| kinsale11 |
| No one else started another thread so here you go. A lot of good ideas have come out of the original thread so lets keep it going. |
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| SuperZoboo |
For projector screens, how can we decide which options are the best and what quantitative methods do we have for measuring gain and viewing angles for different options?
So far I've seen 4 top contenders:
1. Da-Lite Screens
2. PLAS-TEX by Parkland Plastics
3. Blackout Cloth from fabric stores
4. Visiscreens??
this week we're starting our screen from blackout cloth. i post pics and performance numbers (possibly??) in a few days. |
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| HokieTT |
I may be in the minority here, but does anyone else think that just starting nother thread for all of this info is a bad idea? The mountains of unorganized information from the last one will probably just continue if we dump all our new ideas and info into another thread. At the very least, this project deserves its own forum with separate threads. Ideally, a group of forums dedicated to each piece of the project would be used. diyprojectors.com is working on such a forum. I'm sure many others on here, including me, have access to forum creation and management and can start one if need be.
It just seems like an awfully good opportunity to add some organization to this very detail-oriented project at this time.
What do you guys think? |
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| SuperZoboo |
hokie,
i agree. we should use a new forum with better managed groups when one is available, or start several threads here temporarily that attempt some kind of organization while still being under the same topic. perhaps this will work:
DIY Projector - Screens
DIY Projector - LCD Panels
DIY Projector - OHP's
DIY Projector - Result Pics Only
DIY Projector - Custom Designs
DIY Projector - Optics
and etc...i think you get the point. what do you think? would this work or would it become cluttered without moderation?
also, i think we should contribute finished information to a website such as cowan's diyprojectors.com or some other place. ive tried to organize information at my own, but in the future hope to transfer it to a central site.
lets agree to do something, like the new threads, new forum, and/or site contribution and see this project continue to grow! |
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| multiplexor |
| quote: | Originally posted by SuperZoboo
hokie,
i agree. we should use a new forum with better managed groups when one is available, or start several threads here temporarily that attempt some kind of organization while still being under the same topic. perhaps this will work:
DIY Projector - Screens
DIY Projector - LCD Panels
DIY Projector - OHP's
DIY Projector - Result Pics Only
DIY Projector - Custom Designs
DIY Projector - Optics
and etc...i think you get the point. what do you think? would this work or would it become cluttered without moderation?
also, i think we should contribute finished information to a website such as cowan's diyprojectors.com or some other place. ive tried to organize information at my own, but in the future hope to transfer it to a central site.
lets agree to do something, like the new threads, new forum, and/or site contribution and see this project continue to grow! |
hmm i may have had the idea of starting a new thread like this, but then i thought that cowans site would actually be great to continue with this information stream.... I really think it would be great. He already has the forum setup and he also has the sperate forums ready for the DIY projector specifics. |
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| SuperZoboo |
| yeah, cowans forum has/had a nicely laid out forum. for the moment hes switching to a new forum software, but yeah, once its up ill use it too. it would be nice if diyaudio.com would establish a similar organization scheme and throw in a few good mod's. heck, id volunteer to mod if they need someone. |
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| Jason |
| quote: | | heck, id volunteer to mod if they need someone. |
Moderators are being appointed as you type, although they will be "passive" - we don't want a police force just an easy way to keep things tidy and easy to use. Work has already started on cleaning out the completely useless stuff from the V1 thread.
SuperZ: There has been a notice across every forum for the past 4 days asking for moderator volunteers if you're interested.
| quote: | | At the very least, this project deserves its own forum with separate threads |
Did you mean threads, or did you mean seperate forum areas? Did anyone notice the Video forum was created about 2 months ago? ;) Also that the recent site update allows you to view only video discussions?
If you decide on a forum structure then it will be created. Simple as that! I would even consider turning <a href="http://www.diyvideo.com">diyVideo.com</a> into a sister (brother? ;) site on its own if you think that would be a good idea.
Happy to create seperate forums per your suggestion below. Whatever you need, it's not a big deal and I'm happy to provide or create it. |
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| Jason |
<A href="http://www.diyaudio.com/wiki/index.php?page=VideoLinks">A complete list of the 760 links referenced in the DIY Video Projector thread</a> is now available in the Wiki.
If anyone would like to help name and categorize the links I'm sure everyone would really appreciate it! :) Editing the page is of course as easy as clicking the Edit link. |
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| Marklar |
| Well beta 2 is on the drawing board now, that means smaller box brighter bulb and higher resolution. Cooling for these things isnt going to be as big as a problem as I thought it would mine seems to run very cool with just a fan and vent. My friend at the electric supply is working on finding me a bulb, I told him 50,000 lumens 4500-6000K color temp about 10000 hour life and as small as can be so mabey he will have better luck. |
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| multiplexor |
hmm if Jason is willing to do all this, I'm willing to fully stay here. I just saw cowans site as being organized into diff sections, but if that can be done here to. I figure it started here, should stay here :) hehe
Oh, hehe I had sent Jason an email asking for moderator status a while back also. Mainly passively for the V1 thread. But if he ever needs some, I don't mind giving a hand also.
:) |
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| HokieTT |
Can you please tell me how you created a hole in your reflector big enough for the bulb base to pass through?
Also, do you have any more details for us concerning how to get a reflector like yours? I got a reflector in, but I think it might be too shallow to make efficient use of the light. Thanks. |
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| Undream |
| Marklar, you punk! :) you do realize that we could all use a reflector like that. BTW, excellent job. Look what happens, I go on vacation, and you have to go and beat me to the final product. Oh well, I'll be finishing my box next weekend hopefully :) Good luck with your tweaking and perfecting. And thanks for all the great pictures of your progress. Makes me want to work more on the project! Seems like noone posts pictures except me and you Marklar :) .. hrmm.. come to think of it, theres not a lot of people making boxes like us, is there? |
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| Jason |
| Thanks. As I said I don't think we need any kind of in-your-face moderation, just a way to keep an eye on the ball and get stuff done when it needs to get done. I've been working hardcore on my day-job for the past 12 months, and haven't made the time to give this place the attention it needs. Now that the new site revision is done it's a lot easier for me to roll with the punches, so to speak :) |
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| Gunawan W |
Hi guys,
good to see you again on this new thread.
Let's continue our discussion.
Last night I made some test with fresnel panel.
As per woneill idea and from this link, which placed the fresnel panel in front of the LCD panel!
I put the fresnel 1,5" in front of the transparancy and I was surprised with the result, the projected image quality almost unchanged! there was slightly blurry at the image edge, but I think this was because my fresnel has a lot of scratched and slightly bended.
In this test, the fresnel panel doesn't act as objective lens, but as collimated lens.
If you already have 2 fresnel panel and LCD panel, you should try yourself and see the result.
The setup should go like this:
The light source should be placed at 1 fl of the first fresnel to produce parallel beam and will pass thru the LCD panel (placed right in front of it) and then hit the second fresnel panel (placed 1" to 2" in front of the LCD panel).
Light beam out from the second panel will collimate at 1 fl and at that point the objective lens should be placed.
This setup will answer one of the two LCD panel lighting conditions (another conditions is polarizing beam).
see you... |
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| blahn |
Marklar,
Have you thought of using an adjustable 90 deg projection lens ,like overhead projectors, with your setup? so you could lean the box upright against a wall, out of way, and still be able to adjustment the image placement? |
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| woneill |
Hi Guys,
Good to see that the spirit lives on!
One possible downer about multiple other forums and web sites is that the previous thread acted as a single nexus for creative ideas from all over the world - some good, and some bad - but all were brought to scrutiny in one place, and while the thread was awkward to navigate, it was a single point of reference.
Anyway, back to business - there is actually a second reason I wanted to follow the LCD by a fresnel and concave lens - independent of collecting the maximum light through the LCD and maximising the contrast of it: I wanted to produce as parallel a beam as possible feeding into the main objective.
Why? To test my idea about anamorphic widescreen...
The theory is this - if you pass the beam through a concave cylindrical lens, and then subsequently pass the beam through a convex cylindrical lens of the same focal length, then in theory, the beam should be widened along one axis without disturbing the other one. With the two focal lengths of the lenses being equal, then I am hoping the overall focus of the beam will not be affected either.
Alternatively, using four cylindrical lenses (two PCV and two PCX) a configuration might be possible where the vertical axis gets compressed, while the horizontal axis gets expanded. This arrangement might be preferable because each axis gets "interfered with" less than with the single pair of lenses. Alternatively, each lens might introduce so much distortion that a less lenses is better. I honestly don't know.
I haven't tested this yet, and am waiting for my new lenses in the mail. But for this to work with the least possibility of distortion, I would guess that the more parallel the beam as it passes through this lens arrangement, the better... Hence another reason toplace a concave lens as close as is optimal to a fresnel after the panel.
I am only guessing about all this at the moment, and as I say, I have not tested it. What do you guys think?
Bill.
P.S. Gunawan, did you test the arrangement with the fresnel out on a laptop panel first to determine a rough optimal "viewpoint" for the image coming through the fresnel? This is probably very different from the optimal focal point of the objective lens. Having the actual viewpoint of the fresnel too close, or too far away can result in significant corner distortion. |
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| Marklar |
blahn
Marklar,
Have you thought of using an adjustable 90 deg projection lens ,like overhead projectors, with your setup? so you could lean the box upright against a wall, out of way, and still be able to adjustment the image placement?
That would be what Im gonna do with beta 2, I really want to find like an old grandfather clock or something like that and cram all the stuff in there so it sits at the back of the room and looks like a peice of furniture.
HokieTT
Can you please tell me how you created a hole in your reflector big enough for the bulb base to pass through?
Also, do you have any more details for us concerning how to get a reflector like yours? I got a reflector in, but I think it might be too shallow to make efficient use of the light. Thanks.
I used an air die grinder to make the hole bigger as for making it the right size i had to find the focal point so i stick my finger in the hole umm hehe anyway i put it in there and looked stright at the reflector until the reflector turned flesh color then I measured the bulb and marked a hole then cut it.
Here is what I got the reflector off of.
Cooper Lighting |
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| Marklar |
| For any of you that use IRC I made a channel on dal.net #diyprojector come join and chat. |
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| thelaw |
has any one heard of or used the NView Spectra Pro. Its an 800x600 panel but i cant dig up any specs on it.
cheers, |
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| icculus |
| for anyone with the fuji vp5110b projection lens, i bought one from edmund for six bucks. as is, it's practically useless, but if you take it apart, there's some pretty decent lenses inside. i think this is the same one that surplus shed is selling for more money. it's got 2 pcx 1pcv and 1 dcx. i haven't made any precise measurements on them yet, but i am able to project a clear image with the convex lenses. i may try using the pcv in my light stage(before the image) |
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| icculus |
| how are you going to mount all these lenses? |
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| woneill |
Icculus,
The same way porcupines make love - very carefully... :D
Unfortunately the mechanical side of things is my weakest skill.
Everything up to now is stacked vertically on my ex-OHP. The lenses I have up to now, are each mounted individually on 12"-square pieces of chipboard with an appropriate hole cut through the middle.
The fresnel on the OHP is simply glued to the chipboard panel. The other lenses (6 3/4" DCV, 5 7/8" PCX) so far, are clipped to their panel using loudspeaker mounding clips.
I have a crude concept of "legs" for each lens-panel based on blocks glued into the bottom side of each panel that have bolts screwed into them - each block is about 1.5" thick, with a hole running through it and a mounting nut super-glued to the bottom; appropriate length bolts from Home Depot are used according to requirements, screwed through the nut, into the block, to adjust the height of the panel above the previous one...
It is very "physics lab" at the moment, and not kid-proof.
Once the optical arrangement is perfected, I shall have to devise a more permanent enclosure...
As for the "anamorphic lenses", I don't have them yet. they are on order from Einstein's Emporium:
http://www.einsteins-emporium.com/s...ptics/sl230.htm
They are 2" square in section, and I am intending to mount them (glued) stacked vertically in their own rectangular tube that can be added/removed as a single unit depending on the characteristics of the DVD being watched.
When I get myself a new camera, I'll post pictures.
As for the internal arrangement of the anamorphic lenses, I have ordered 2 each PCV/PCX lenses, and depending on what works, I am thinking of cementing two pairs of PCV/PCX lenses together at right angles to each other as doublets that can be mounted a couple of inches apart from each other...
Hope this helps,
Bill. |
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| HokieTT |
Thanks for the help, Marklar.
Next question, for anyone who has made a screen with blackout cloth: which side do I use? One side is coarse and cloth-like, and the other side is smooth and rubber-like. They're both about as white as can be. Which side does the picture show on? Thanks. |
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| SuperZoboo |
generally, the rubbery side is used. its easier to clean too. the forum at www.avsforum.com had several good threads under the screens section if you wanna good read. one guy made a nice frame for his.
as for ours, Krazzyed took it home to his mom so she can stitch a 8 foot long "rod pocket" for our dowel rod to slide into. as far as design goes, frame vs hanging, this may or may not work that great. it will be a week before we know.
meantime, if you finish, let me know eh! |
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| EternaLightWith |
I was browsing THG and I saw some news on Sony introducing a new LCD display. Looks interesting. Sorry if you guys know aobut it already. Just sending a heads up.
Eternalightwithin
Here's the full article at the digitimes.
http://www.digitimes.com/NewsShow/A...pages=03&seq=16 |
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| multiplexor |
it's funny cause i work at a company that has so many links to websites with electronics, capacitors, resistors, lcd screens...
yet i never bothered looking for some handy links to company web sites... I think i'm going to start trying to find some handy links to these sites and see whoe and where they sell stuff...
maybe i might find something handy.
anywho, just wanted to share :)
Curious, but what have people been doing for posting info lately?
have you been using cowan's site? or still plan on only posting here?
ciao |
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| fender4 |
Hokie TT and SuperZoboo,
I recently purchased the blackout cloth, and mine has one white side and one tan side...so picking which side was not tough! ;)
I am happy with it so far. I don't have a frame/backing for it right now, but I was thinking about getting a 4x8 sheet of foam insulation board from Home Depot (I think it is pink with some writing on it). I plan on making it a 90" diagonal for 4:3 viewing, so it will take a little trimming and glueing. My goal is a lightweight, movable, durable screen, so that foam board might be good. I think it was $6, so the price is right.
Good luck,
f4 |
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| SuperZoboo |
fender4,
yeah, we got the yellow sided stuff too! anyway, i like your idea maybe a bit better than ours. i might halt the stitching progress. what dimensions are you going for? it seems that if the cloth is 54" you could do:
54" x 71.82" (4:3 ratio)
54" x 96" (16:9 ratio)
with the dowel rod aproach we lose height for the rod pocket and ultimately will have something like 48" x 85" (16:9).
alternatively, with a foam board and a 1 inch black felt border i guess the max would be 46" x 81.42" (16:9) or 46" x 62" (4:3).
still, i like the foam board idea and we might just go for it instead. what dimensions are you using exactly and do you think you'll use a felt border? |
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| SuperZoboo |
Jason,
Its been several days and cowans forum has yet to be restarted. I have no preference and want nothing but a forum thats reliable and moderated. And someone else said why not this forum since it started here and its well known. So i suggest these categories for a new subdivision of the video section:
DIYaudio Forums > Top > Video > DIY Projection:
Subcategories within "DIY Projection"
Screens
LCD Panels
Enclosures (OHPs, OHP mods, custom boxes)
Optics/Lenses
General
Of course this might need refining so any other suggestions would be great. I say make it so if you can and move the big threads, but closed for responses. |
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| cowanrg |
i would restart my forum, but due to traffic, and lack of overall interest, it really hasnt been much of use.
it's nice that this forum is shaping up a bit, but it does still need work IMO. |
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| noodles |
I was kinda interested in seeing how cowan's forum was coming along. It had more appropriate categories for this kinda thing.
When I put my Spectra C on my OHP, do I need to take the stage glass off the OHP first? Mine has two layers of fresnel, the glass, then the Spectra on it. My LCD itself is quite a bit smaller than the stage and there's lots of space left. But the rest of the LCD panel covers it up. Should I worry about this?
Oh yeah, I just remembered. What aspect ratio should I be using with the Spectra C? My screen is 4'x7' Visqueen plastic. It's barely thicker than a shower curtain. Do I have to cut it to 4:3? Will it leave out light, or does it project black at the top and bottom of widescreen? |
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| cowanrg |
yeah, i really wish people would have been more interested in my forum... i just didnt have the time for it to work (as of now....). im just one person :-)
i didnt touch anything on my OHP to do what i did. i only removed the LCD panel and housing from the spectra c. mine just has mirror, fresnel, glass. but i have a 1" thick fresnel, that is kinda encased (not really, but both sides are smoothed, its kinda like enclosed.)
as far as the size of the spectra, that's what makes it ideal. with normal OHP's you get a hot spot in the middle, and the edges have little light. the spectra is situated in the middle of the stage, and therefore where the majority of light is.
this allows it to have the most light possible. i tried this with larger lcd's and the image was MUCH dimmer. plus, if you totally mask the rest of the stage (recommended), you get VERY little (none if you are good) bleed through from the excess light. mine projects ONLY the panel, and there is NO light coming from the projector, except for the fan vents.
so, i suggest mounting panel fairly flush (mine has rubber pads to create a ~1/4" gap that allows for airflow underneath panel.) i noticed that the extra light that bled out brightened room, and in a sense, created an ambient light equal to a small lamp being on. making the image a tad more washed out.
now, the screen. since we use really shi**y LCD panels (150:1 contrast ratio is BAD in the relative sense) blacks aren't quite black. on a spectra, we get a kinda dark grey. there are a few ways around this.
if you only watch widescreen or letterbox (or fullscreen, read further), mount your screen so it's at a level where you can lower it JUST enough for the picture to be shown on the screen. however, the light from the "black" bars will just go onto the wall or whatever, and wont look to swift (yeah, i said swift :-)
so, i do the ghetto version. goto an art store, and get some picture frame matting. if they are nice (or if you are a smooth talker) you can get them to cut some for you. or give you some for free.
take the strips, and cut them the width of the LCD panel. now, you have inserts that you can set inside the LCD frame (on the spectra, there is a black "ridge" piece of metal that kinda makes a frame for the lcd. you can set these strips of matting inside this, and bam! you have a letterbox. get them for various aspect ratios. just play a movie and measure the dead space on top and bottom.
it looks AWESOME if you do it right. you get a widescreen image projected, with SHARP corners. it looks like its that res native. it really looks great.
for the longest time, i just used 2 pieces of thick letterhead paper, and just kinda propped them on top of the panel, so that they cut out the black strips.
but with any panel of this low contrast, you will have nice and ugly grey bars projected. its even worse if you have a high gain screen, like a glass bead impregnated screen like i do.
plus, another tip for DIY screeners, put a nice black edge on the sides of your screens... this will look a lot better than trying to fit the image perfectly inside the screen. this will give you a better margin, and if its a nice black, you wont even be able to tell the projected image is overlapping.
well, thats my 2 cents. hope it helps some people. da**, long post, guess i had to make up for my lack of posting lately. hehe.
| quote: | Originally posted by noodles
I was kinda interested in seeing how cowan's forum was coming along. It had more appropriate categories for this kinda thing.
When I put my Spectra C on my OHP, do I need to take the stage glass off the OHP first? Mine has two layers of fresnel, the glass, then the Spectra on it. My LCD itself is quite a bit smaller than the stage and there's lots of space left. But the rest of the LCD panel covers it up. Should I worry about this?
Oh yeah, I just remembered. What aspect ratio should I be using with the Spectra C? My screen is 4'x7' Visqueen plastic. It's barely thicker than a shower curtain. Do I have to cut it to 4:3? Will it leave out light, or does it project black at the top and bottom of widescreen? |
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| Undream |
cowang, darn you. hehe. I already had this idea, and had yet to post it. I'm going to be taking sheets of really cheap sheetmetal, and cutting them to look like this:
I'll make one for 16:9, and 2.35:1, and just slide the sucker right into the side of the projector (I'm making one side of it on hinges that can easily be swung open) whenever I watch a widescreen movie. |
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| SuperZoboo |
rats, both cowan and undream beat me to my revolutionary solution. we just find whatever scrap paper or trash we might find on the floor (junk mail works good) and line that up to block the light.
seriously, thanks for the tip cowan. i think ill find some matting soon.
btw, im gonna buy a little digital thermometer from radio shack for $20 to monitor heat. what do you think about putting a PVC 90 corner over the vents to cut down the light some? think it will block the flow enough to overheat the innards? |
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| HokieTT |
Hey guys. I finished my screen a few minutes ago. If it looks crooked on the right, it's because the base was further way from the wll on the right than on the left. When put flat against the wall, it's perfectly square. For a reference point, the TV on the left is 35" diagonal.
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| Undream |
awesome :) is that plastex? nice to see someone following in my footsteps.
its fun as hell to build, huh :) goes together so darn quick. so much easier than the crappy projector itself. You think to yourself.. Hey, I *am* capable of doing something after all!!!
hehe. then you go back to your projector :) |
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| cowanrg |
the matting works well, becuase its easy to get, and it blocks light. plus, if cut right, they fit RIGHT in the corners of the panel, and takes about 1.2 seconds to box out your panel.
as far as the temp guage goes, dont even bother. here is a rule of thumb for panels, if you can put your whole hand over it when its on, and it isnt uncomfortable, its fine. if its kinda hot (meaning it almost hurts), its too hot. they can stand up to quite a bit. you would really be surprised how hot their tolerences really are. and believe it or not, our skin is one of the most accurate thermometers. save the $20, and just use a hand test. if YOU can handle it, so can your panel. we have low tolerences for heat.
of, if you wanna spend $20, let me know, ill give you my paypal account :-)
sorry about beating everyone to the tip. hehe, i still lurk around here every so often.
| quote: | Originally posted by SuperZoboo
rats, both cowan and undream beat me to my revolutionary solution. we just find whatever scrap paper or trash we might find on the floor (junk mail works good) and line that up to block the light.
seriously, thanks for the tip cowan. i think ill find some matting soon.
btw, im gonna buy a little digital thermometer from radio shack for $20 to monitor heat. what do you think about putting a PVC 90 corner over the vents to cut down the light some? think it will block the flow enough to overheat the innards? |
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| fender4 |
Hey Undream...I'm disappointed! Why stop at hinges? I want to see some automation! How about an auto-aspect ratio selector controller from an HTPC? Sorry, couldn't resist. :cool:
Good ideas, everyone.
SuperZ,
My math is terrible, but I came up with:
90" diagonal, 4:3
72" width X 54" height
My blackout material is also 56", so I left an inch on each end to play with. To construct these dimensions with the 4'x8' foam board will require some cutting and gluing. There will be 24" of length left after I cut the board down (because of the 4:3), so I will use the excess material to fill in the missing height (48" extended to 54". I will try to be precise with the cutting and gluing, but since material will cover it, absolute precision is not critical. I will probably add a black felt border. It seems like the practical thing to do.
I hope to make some progress this weekend on the screen and the projector housing. I am still looking for a Marklar-esque reflector for a MH setup, so in the meantime, my DYS halogen-powered projector will double as slow-roaster. Should work out great for the 4th of July!
-f4 |
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| cowanrg |
i actually had plans for a motorized setup for my aspect ratios, but to tell you the truth, it would be hell! you would have to get a stepper motor, motor controller, and basically have set aspect ratio sizes programmed, etc, etc, etc, etc..
so, i thought to myself... why!? im usually one to overdo things, and typically, if its a hassle, i go for it, regardless of benefit :-) but this was one of those things that for the simplicity of dropping 2 cardboard pieces down on the panel, as opposed to building a contraption (which wouldnt work as well, because it would have to set OVER the panel, couldnt set right on top, because of space issues, you wouldnt even have crisp clean lines....
been there, thought about it, didnt done that. |
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| noodles |
We're already ghetto-ing the projector, why not case mod it? A thermometer would be kewl if it was backlit. Window kits would be kinda stupid though for these cases. :D
Well you could line your (let's call them) "aspect boards" together, kinda like a book. And put a hinge on the top/bottom. Then you can just flip the one you want over and WHAM!!! You got yourself some keen innovations. The only thing you have to worry about is the order you put them in. Don't put the one with the big hole in the front, because it will block the ones with the littler holes. Get what I'm saying? Maybe I should draw a pic for it.
minutes later:
Yeah, I'm no artist when it comes to MSpaint. But it basically shows the order of the boards. Putting them in this order will prevent them from covering each other up. Pretty average concept. This is the kinda stuff that comes out of my brain when I don't go to sleep. |
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| eebasist |
After seeing what Marklar did i think the thread would benefit by a very good rundown of the calcs that he did and how they were used.
I have a basic understanding of focal lengths, but like a lot of us dont really know enough.....i've read all 2K posts so don't say read them..
Specifically, can anyone tell me what calc Marklar used to find the dist between his light source (it has a focal length right and a lens right) and the fresnel/lcd......but more importantly how to do the distance between the lcd and lens and wall. What size aperature of this lens is necessary? I plan on using a lens that has a small aperature (35mm SLR).....if someone can give me a good set of calcs and what numbers are important it would be appreciated.
I already have an LCD/OHP, but would like the quality that Marklar's design has........i just dont know what calcs were done for bulb/light source placement.......what determined where in the reflector the bulb goes, where the lens in the reflector goes, and how far from the fresnel/lcd the light source goes. |
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| rmccoll |
COOLING IDEA
allcorp has a thermoelectric cooling unit it's like miniture refrigirator it can produce cold temperture up to 68C in a small area this is great those metal halide bulbs it cost 26.00 at www.allcorp.com
I don't need this because i'm using a compact flouresent bulb from lights of america that puts out 3700 lumens. If you go to www.topbulbs.com they a compact flouresent light bulb that puts out 12000 lumens put it's 11 inches long. |
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| cowanrg |
TEC (thermoelectric cooling) is nice, but its HIGHLY unpractical, unless you are super cooling. you can really only cool point ot source with it. large surface area is really hard to do.
seconldy, they have MASSIVE condensation issues, so it has to be fully insulated, becuase you dont want moisture inside the projector.
lastly, they get cold, but they also get equally hot... i had a medium power heatsink/fan on one once, and it burned up in less than 30 seconds. you need to REALLY cool these things. and, that creates noise, but you have to get the heat OUT too. and powering them isn't the easiest task. they take a lot of power.
the thing is, we dont need something like that for this application. a fan will be FINE. just make sure its a GOOD one. i suggest a panaflo (panasonic). i have some that push around 60CFM each an operate silently. you can boost the power up a bit, and get 87cfm from them, and they are still barely audible. i used them to cool a radiator for watercooling.
quality, not quantity. a CPU in a computer gets in the hundreds of degrees C within seconds if not properly cooled. our projectors dont come close to that... and hell, we can cool the chips with just a heatsink and fan, as long as we dont expect amazing temps.
if a CPU can operate like that, i think our stuff can too.
| quote: | Originally posted by rmccoll
COOLING IDEA
allcorp has a thermoelectric cooling unit it's like miniture refrigirator it can produce cold temperture up to 68C in a small area this is great those metal halide bulbs it cost 26.00 at www.allcorp.com
I don't need this because i'm using a compact flouresent bulb from lights of america that puts out 3700 lumens. If you go to www.topbulbs.com they a compact flouresent light bulb that puts out 12000 lumens put it's 11 inches long. |
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| eebasist |
| Yeah, TECs are nice, but not for this app....they draw a ton of power, and they have to dump the power somewhere.......they get awfully hot and require a huge heatsink wich requires something to cool it. Our MH bulbs have too much surface area to even think of placing these on them.....not to mention you couldnt evenly distribute the cooling properties resulting in hot and cold spots wich would most likely cause the glass to crack from the thermal stress |
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| Marklar |
| Well let me say this dont build a projector based off of mine, it is nice but it needs tweaking. As for how I got my distances I didnt use any math I just layed everything out on a table and moved everything around untill it looked good. Math cant tell you if your gonna have a hot spot so you just have to play with it. I have also thought about using something to block the lcd when I want to watch wide screen but i have a nice da-lite pull down screen so i just pull it down to where it reaches the bottom of the image and Im gonna put a black cloth at the top to absorb that light. I tell you what Behind enemy lines was awsome in letter box the fighter jet part owned on the big screen :P. I can watch it during the day but I have to close the blinds. well thats all for now got any questions? |
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| eebasist |
| Marklar, what type of lens did you use at the opening of the light source? Is that just sheet metal with a lens on it? Also can you explain how you decided where in the reflector to place the bulb? I dont quite understand what you said by putting your finger in and looking for flesh color.....I'm not copying your design...I plan on modifying it signifigantly, but need to understand yours better first |
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| eebasist |
| what focal length was your projection lens.....i'm contemplating useing a crt projection lens to keep light output high. Just thought my 35mm lens might be too small an aperature for enough light to go through |
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| woneill |
Hi Guys,
Here's a whacky idea that might be of interest to those people with LCD monitors and Laptop Panels...
Would it be feasible to remove the CCFL Panel backlight and replace it with an "apparatus" that used an elliptical reflector surrounding either a 300 Watt double-ended halogen ("Torchiere" variety), or a high power fluorescent along the lines of the 11" LOA-style offerings mentioned above?
The halogen option would need an IR filter and excessive cooling in order not to melt the LCD, and all options would need some kind of long thin cylinder lens (possibly the cheap plastic type available for magnifying sections of pages).
The idea is that these panels already have a very efficient mechanism in place to give a uniform distribution of available light to all points on the LCD surface, and also to get that light to come out from the front of the panel.
Gunawan has already ratified that I am not criminally insane for suggesting the use of a fresnel in front of an LCD panel to collect all of the emerging light and focus it on the main objective.
If we could utilise the existing efficient mechanisms in a LCD monitor, but using a more powerful light source, we could produce a nice, compact hi-res projector...
Thoughts, anyone???
Bill. |
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| icculus |
| i think it nas been previously discussed that these(laptop) panels have the potential to be our ideal image source. the problem is getting controller boards for them at a reasonable price. check outearth lcd we're talkig $300-$400 for the setup. I'm hoping to find something a little less costly. if anyone can find a small( under 10") lcd monitor for less than $300 that would be perfect, as long as the controller, inverter, backlight can be easily removed from the light path. |
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| prjctr_builder |
we can use the lcd monitor, but i prefer to use a panel, because a panel is a lot smaller and is made for projection. and in any case you will HAVE to use some type of objectives to project the image. that will add whatever the focal length of the lens is to the length of a projector. BUt i am working on a new design that will cut projector size by a good 1/3. tell you later, gotta go.
aleksey;) |
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| woneill |
Hi Guys,
Good stuff! I was actually thinking here about using a laptop panel directly connected to a laptop - my primary DVD player IS my laptop. :)
It gives me progressive video at the 24fps of the original film, while automatically scaling up the video resolution to match the screen.
For many laptops, a second LCD panel can be bought fairly cheaply, and the idea of being able to wire my laptop into a secondary screen that was driven by a much brighter light source than the standard CCFL tube is interesting.
A standard LCD monitor is a more flexible, but possibly more expensive alternative.
The technical question is whether the issues of trying to remove the back of the monitor panel, performing micro-soldering to extend the ribbons, and then building a massive light enclosure to get even lighting across the back of the LCD, can all be avoided by "squirting" a high brightness light source down the normal light path that the panel's standard edge light would use...
In effect, it would bethe equivalent of turning up the brightness of a standard LCD monitor (or laptop panel) by a factor of 100 (guessing here) and using that light source with a fresnel and suitable objective to project an image.
Bill. |
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| biteon |
i like your idea with the aspect boards. getting rid of some of that extra uneeded light can help the projected picture look better to the eye, sharper apperance,& i think it looks like it changes the contrast to(i did some tests with some like that when i first started trying to get my tv to project a picture on the wall).also i dont no to much on this but im guessing it might help with blurry edge's on the projected picture.
i was trying to find out how to make a setup where i would have all the aspect boards attached in one unit,you just answered that so thanks.
:D :D :D :D |
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| Marklar |
| quote: | Originally posted by eebasist
Marklar, what type of lens did you use at the opening of the light source? Is that just sheet metal with a lens on it? Also can you explain how you decided where in the reflector to place the bulb? I dont quite understand what you said by putting your finger in and looking for flesh color.....I'm not copying your design...I plan on modifying it signifigantly, but need to understand yours better first |
Yes I just robbed the lens that was in front of the light that was on the dukane 680. with the reflector I put my finger in the hole where the bulb goes and looked stright at the reflector and it reflects my finger on the sides of the reflector when my finger was at the focal point. My projecion lens is 327mm right now but Im going to get a 450mm so I can move my screen back. |
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| prjctr_builder |
Is having the 750 hour lifo on the 575W bulb out of dukane 680 the only disadvantage? cause i wanna try to use it. the reason is that i do not wanna spend any more money buying the ballast and other things.
aleksey:) |
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| woneill |
Aleksey,
The 575W MH bulb is actually quite nice for projection - it has a small spark gap (7mm - much smaller than the standard 400W bulbs) a high colour temp (5600K), and I have seen them for as little as $90 (ish).
It is a small bulb in comparison to the standard 400W modules, and can be mounted (with a little ingenuity) in a parabolic/elliptical reflector without too much difficulty - giving a VERY nicely profiled beam.
Osram now make them with 1000 hour life, but you pay much more for that.
Now the down-side: They are not compatible with the standard 400W ballasts; they require a high voltage igniter; and run very hot. It would appear that they run SO hot that the ballasts (usually electronic) and/or igniters fail prematurely. (I have encountered three dead ballasts in old projection equipment in the last couple of months...)
The ballasts/igniters are a pain to find replacements (or components) for, and those that can be found cost a fortune due to these bulbs being used in photo/film lighting equipment - such stuff costs a fortune...
Despite this, it is my bulb of choice when I can get suitable ballast components to drive it (cannibalised from DOA old projectors...)
If you have a system that uses such a bulb, and it is in good working order, then you are in luck! Treat it nicely and Enjoy!!!
Bill.
P.S. Forgot to mention the most important point: an output of 49000 Lumens... |
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| braxton |
I got a sharp qa-1650 off of ebay- purchased beginning of May.
I asked to have it shipped to my sister's place in the US so she could bring it when she came to visit (I live in canada and wanted to save on shipping-he quoted me $90 shipping to Canada-$20 to US). Because the guy didn't ship it until over 2 weeks after he said he would, it did not arrive at my sisters on time for her to bring it. Also, she didn't feel comfortable testing it other than to say it powered up ok. She came up to Canada again today so I could finally test it.
Unfortunately, the VGA input doesn't seem to work, and with the rca video in I only get black and white images from a DVD or VCR.
Im tried all settings from the panel and the remote (ie contrast tint color), but still only get black and white. Haven't tried s-video in yet-will buy a cable tomorrow.
Any suggestions as to what could be wrong?
The weird thing is that the startup screen appears in color and all colors are crisp. The menu is in blue and thats ok too. But screen only shows black and white???
Hope someone can help me. I'm not counting on the seller being very supportive- he never returned emails when I was trying to find out why my panel hadn't arrived when it was supposed to.
Thanks. |
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| cowanrg |
some of the sharps have "modes". maybe check the menus to see if its being TOLD to display only color.
just a thought. |
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| prjctr_builder |
i am afraid that my 600W ballast will give up on me and i will be left with a broken projector. i know that 575W MH bulb is buyable for $70, but if the ballast fails, i will be in deep touble.
also you know how in dukane quantum 680, the bulb is housed in between a reflector and a condenser lens, and the whole assembly is quite small. and the fact that they recommend changing the bulb after 750 hours, doesn't mean you have to.
so here we have. up and downs of 575W.
UPS:
small
is housed with reflector and condenser
49000 lumens
nice color
downs:
short life
expensive
it is kind of balanced.
also the 400W bulb gives off blue end of the spectrum, so it may display colors not as bright as they are supposed to be. and that thing is huge, i've seen it yesterday. if i put it in my projector, it will,be huge.
my main objective now is to decrease the size of the assembly, i wanna make mine about two times smaller than marklar's. no offence of course, but i think that we have spent a lot of time here and we have come to a STALL. i do not see a good alternative for a projection panel, so i will use it in my setup, but i will work towards making my design smaller. i will probably have a fold-away design for the objectives. also i am working out a design that will let me cut the focal length of the objectives i have right now with mirrors. it is a bit tricky, but if it works, it will decrease my projector's length by about, say 9", that's a lot.
also i am going to try to take the panel apart and detach the LCD screen form it. if i succeed, i will have a projector way smaller in a diagonal size than any of the ones made until today. DIY of course.
and now i have a question... do you think that i will break the panel if i try to take it apart? consider the fact that i am very handy and cautious.
because having to deal with a 10.4" screen is a lot easier than dealing with a 18" panel ( that's what i have)
and i am planning to get Shapr QA-1800 during the weekend. of course for a reasonable price only. that thing has nice contrast, pallette, and inputs. i hope it will serve me well, if i get it , wish me luck.
thanks...
aleksey:) |
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| Jason |
I assume that no news is good news and so the categories suggested by superZ are ok?
| code: | Screens
LCD Panels
Enclosures (OHPs, OHP mods, custom boxes)
Optics/Lenses
General |
If this is ok for everyone I'll proceed... |
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| Gunawan W |
woneill,
as I mentioned before, there was no distortion on projected image, the image in perfect shape.
Distorsion came up when I looked directly in front of the fresnel panel, like using magnifiying glass.
The problem was, when I placed fresnel closed to the LCD panel (in my case = transparancy), it showed up moire effect. If I moved further away, the image became to big.
I don't know the benefit of this setup, maybe we can get
sharper image with less "lumens" light, maybe it will eliminate hotspot problem with big size LCD panel, if the result will make worsen image, then I will back to earlier setup.
Guys, who own 2 fresnel panel, can you make a test to confirm this setup? Please...
marklar,
you can use mirror to bend light 90 degrees, make sure using front surface mirror.
Actually I have similar plan. I will use hanging cabinet (cupboard?) behind my sofa.
The setup goes like this:
On top is Lamp housing facing downward, next is fresnel then LCD panel, before the beam hit the bottom of cabinet, I will place adjustable mirror to bend the beam 90 degrees to the cabinet door. The mirror also can use as keystone correction too.
Last, I will place the lens set (with zoom adjusment) at the cabinet door.
From the outside, you just see a hole with the lens set (around 3" diameter) at the cabinet door!
see you. |
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| prjctr_builder |
| quote: | Originally posted by Gunawan W
woneill,
I will use hanging cabinet (cupboard?) behind my sofa.
The setup goes like this:
On top is Lamp housing facing downward, next is fresnel then LCD panel, before the beam hit the bottom of cabinet, I will place adjustable mirror to bend the beam 90 degrees to the cabinet door. The mirror also can use as keystone correction too.
Last, I will place the lens set (with zoom adjusment) at the cabinet door.
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this is exactly what i am talking about, we cam eto a stall, and most of the people are satisfied with the results we have now. i think that we need to work on a way to make the construction SMALLER.
aleksey:( |
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| woneill |
Aleksey,
I was checking out the Osram site last night, and they mention that the 575W bulbs can be used with a 400W ballast - giving longer life. They don't specify whether this is the standard magnetic ballast, or a special electronic type.
I searched around the web and found a number of "pulse start" 400W ballasts that might do the job. (The pulse start ballasts include an igniter...)
I suppose a number of emails are in order to tech support people to see if any of the ballasts are ACTUALLY rated to drive the bulbs without going up in a puff of smoke... :confused:
Gunawan,
Cool stuff! I thought you were suffering distortion in the projected image... My experience is that by using this arrangement, you DO get a sharper, brighter, and more contrasty image overall (even with one of the cheap page magnifyers from Staples).
The Proxima 9100 chassis I mentioned, that made me investigate this effect, has a beautifully sharp image: text, even at small fonts, is very sharp and legible - even after having replaced the "guts" with a much lower-res 640x480 projection panel. Admitted, the fresnel that is included with the 9100 is VERY nice quality - but I'm sure that other fresnels of this quality are generally available at reasonable prices.
Bill. |
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| Marklar |
| quote: | Originally posted by prjctr_builder
Is having the 750 hour lifo on the 575W bulb out of dukane 680 the only disadvantage? cause i wanna try to use it. the reason is that i do not wanna spend any more money buying the ballast and other things.
aleksey:) |
Thats what I was using for a while until my ballast blew up. I tryed to fix it but I couldnt find the part for it. |
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| Jernau |
Hi all again
http://www.hexachain.com.tw/modules.htm#b
The HC6401A LCD panel shown on there - has anyone ever taken one to bits, or know what's inside and wether or not it can be used in a projector?
Cheers :)
Jernau |
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| cowanrg |
it really depends on price, but unless this is the cheapest panel we've found, i don't think its worth it. the res is alright (still that low 234 vertical), but the contrast ratio is what bothers me. its only 120:1. which, isn't bad, but its not all that great, especially for a normal LCD panel. ususally they are much higher.
plus, for all the comp users out there, its ONLY NTSC. if its cheap, could work, but hardly a new find.
| quote: | Originally posted by Jernau
Hi all again
http://www.hexachain.com.tw/modules.htm#b
The HC6401A LCD panel shown on there - has anyone ever taken one to bits, or know what's inside and wether or not it can be used in a projector?
Cheers :)
Jernau |
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| Marklar |
| Well I built my new site its starting to come togather real nice check back often I will be starting projector #2 soon. hommie.net |
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| SuperZoboo |
Marklar,
Rockin Site! The more we pool what we've learned and offload it to well organized sites the quicker newbies come up to speed and progress continues! I'll admit that for sure you and some other guys have made some nice work, so far I've taken the easy way out. Next week I'm ordering the bulbs and reflectors and going nuts.
In fact, I plan on posting what I hope to order and posting it for review beforehand. What can you tell us about the super-secretive, skunk works project 2 you're working on? Still going with the same MH bulb and reflector?
btw, Thanks for the props on your website! |
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| cowanrg |
lookin good! wish i could do graphics :-(
my new site will be rolling out in the next couple days, almost double content, and all new look. i will DEFINATELY have a link to you.
nice job man.
| quote: | Originally posted by Marklar
Well I built my new site its starting to come togather real nice check back often I will be starting projector #2 soon. hommie.net |
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| Undream |
You guys are going to laugh at me.
Last week on Tuesday, I got shipment of a 400W MH bulb. 40k lumens, etc. It was going to be my final bulb for the project. Well, I opened it up at work a couple of times, checked it out a bit. When I was driving home from work, my wife called me on the cell and told me to go to her moms, because thats where she was. So, I did, and I took the bulb into their house so I could show my father-in-law. Hes been real interested in my projector. Anyways, after we were done visiting, I packed it up and went home. I threw the box in our kitchen, and forgot about it until the next day. The next day, Wednesday, was junk night. With all the chores I was doing and everything, it totally slipped my mind that I had never unpacked the bulb from the box. And, surely enough..
I THREW AWAY MY MS400/HOR METAL HALIDE BULB!!!!!!!!
I didnt realize what I had done until Friday evening. Searching all over the house for a bulb that wasn't here.
/me cries.
Anyways, heres latest pics.
my solution to mounting the lens:
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what it came out like (it will work great)
latest pics of the box - main box is completed, so, I just have to build the front moveable lens assembly! Also, notice the hinges. Any guest will surely say "DUDE! CAN I LOOK INSIDE!"
this one, I was holding up the lens in the approximate position :D :D
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| MikeZupcak |
Im thinking of building a video projector but using a 7" 16:9 aspect ratio LCD. I had an idea for a light source: a 1,000,000 candlepower spotlight. This is the LCD i was considering:
http://shop.store.yahoo.com/besttoys2/tm7001s.html
The spotlight seems like it should be bright enough. If anyone has seen Zark5150's original projector i was thinking of one along those lines, with the light behind the dismantled screen. I am also wondering how many lenses i will need and where i can find a barrel lense. Would a megafying glass lense inside some sort of PVC tube work? Also, does the lense need to be big enough to fit over the entire LCD module?
Thanks for your help good luck to everyone!
-Mike
Mikez871414@yahoo.com |
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| jco9w |
Well I think I have beaten my Macrovision problems. I bought a Macrovision buster on ebay, not expecting it to work very well. I finally got it last week, threw everything on a 3M 9550 OHP and checked it out. The Macrovision buster had a handy on/off switch so I could turn it on and off at will. I didn't really notice much of an effect on picture quality with it on, some of the colors changed slightly, but it actually looked better in my opinion. So I am considering that problem solved.
Now I want to go ahead and buy a 400W MH light and I am looking for reccomendations. I want a reasonably sized bulb, so can those of you with MH bulbs give me there rough dimensions (just assume they are rectangles)? Also, if there are some catalogs that I can use to get this sort of info, can you guys point me to them?
thanks to everyone in advance
J |
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| Undream |
MikeZupcake:
First of all, you need to realize that candlepower is an extremely misleading rating. A 1,000,000 candlepower spotlight is usually a 75-150W Quartz Halogen that puts out at most 2,000 lumens. Check my site update that I did on MAY 6. heres the link:
http://www.dreamlash.com/DIY/may6.html
In fact, as a test, I picked up a 2,000,000 candlepower handheld spotlight for kicks. I returned it promptly when I couldn't project a damn thing with it. |
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| noodles |
| I plugged in my nView Spectra C today and it came up with a blue screen saying nView SPectra C. I plugged it into my puter but no picture appeared. What gives? I'm thinking it could be a bad remote. HELP ASAP!!! |
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| HokieTT |
| A few things to check, noodles. First, make sure you aren't plugging a VGA cable into the 'optional monitor' port on the Spectra...that's a monitor OUT port. Secondly, make sure your computer's resolution is 640x480 with 16K colors, and make sure the refresh rate isn't too high (I've only tried up to 70Hz on mine). |
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| HokieTT |
Guys...
As I continue to go forward with my projector, I'm getting nowhere fast. I've got the 400W MH bulb mounted with a 12" parabolic reflector, and I can slide the reflector up and down the length of the bulb to try to find the focal point. However, I can't seem to produce a significant folused parallel beam of light with them. And no matter where I position the reflector, I can't get my fresnel lenses to converge the light whatsoever. It has become very frustrating. Any ideas? |
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| Marklar |
undream,
you got a big enough lens? how big is that thing? |
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| Undream |
5 7/8"
I spent an hour or so doing some trigonometry to figure out the angles / lengths / different sizes of the pieces I am going to be cutting for the front lens mount. Talk about hard to do, I can see why you didn't slope the lensmount down to a smaller size, its killing me :) |
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| woneill |
HokieTT,
Part of the problem could be that you might never reach the focal point of the reflector with the "hotspot" of the bulb.
Have you tried Marklar's excellent trick of looking head-on at the reflector and poking your finger through the back - moving it towards you until the whole reflector contains a giant image of your fingertip? (Remove the bulb first, of course...)
;)
The point where the reflector fills up with your finger is the focal point of the reflector, and this is where the hotspot of the bulb should be. (You might need to enlarge the hole in the reflector to allow the bulb to fit that far back.)
One other problem is that even if you get the position right, the bulb hotspot is not an actual point source of light, but is instead an elongated strip.
If you want to use this combination of components, you should put the centre of this hotspot at the focal point. The end result will be a fairly uniform beam with some divergence, and some convergence. If you get it right, and the reflector is bigger than your LCD panel, you might not need a fresnel between the reflector and the LCD - the reflector will have done the job of spreading out the beam.
In this case, you should definitely experiment with putting the fresnel before/after the LCD to see which gives you the best results. See previous comments on this concept and explore.
One thing - a 400W MH bulb is going to kick out a LOT of UV and IR... You will definitely need some heavy duty glass between the bulb and the panel, and possibly some fan-cooling too...
Bill. |
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| woneill |
Undream,
Beautiful craftsmanship! I use a similar arrangement myself with my 5 7/8 PCX, but mine doesn't look anywhere near as good!!!
Bill. |
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| biteon |
i have seen your web page and came up with some ideas.
1. with all that room in your box im guessing maybe it might be better ifyou use a air tunnel type of thing to cool the light cause where your fan is at on your reflector is where most or alot of could be reflecting forward but instead its going right out the fan hole.
2.connecting a pipe to the fan thats cooling your light, alll the way to the out side of the box or what ever. so the fan gets cold air and not the hot air in the box.also when and if doing this you'll need and exsost for the hot air to exsit.maybe a hole at the top sents hot air rises.
well that what im working on now basicaly. no i havent tryed it yet. i just sent 3 day making a mirror reflector with integrade air tunnels on the outer sides of the refletor mirrrors.at the opening perimeter is where the air shoots forward then the air hits the glass sparationg in my box and comes back to the bulb and out the opening where the bulb gose through then out the exsost.
maybe i should draw a picture. it might explain it a bit better.
my reflector is made from ride aid cheap mirrors that i cut up to peices,sheet metal and 200 F temp resitant poly some thing grey duct tape(i found it laying around the house ,im stoked but still not sure if the tape will work).
other than that i think your settup is pertty dope.
like the lens , tell me if it works out. later :D :D :D :D |
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| MikeZupcak |
Thanks for the help with the candlepower! Im looking for recomendations for a light source as well as an LCD. I want to use a 16:9 LCD and found one for 200. Can anyone tell me if this is a good one to use?
http://shop.store.yahoo.com/besttoys2/tm7001s.html
Also...im wondering about what types of lenses to use for this and how they should be arranged. Anyone got any diagrams?
I liked the way Zark5150 did his original design if anyone saw that. Also, anyone using ultra bright white LED's?
thanks
-Mike |
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| jjasniew |
This is a 600W, 2000 hour bulb, latest design. Brand new, never used. First $40 into my paypal (joejas@ihpc.net) gets it. This bulb is supposedly temperature expansion compensated, vis-a-vis its mechanical mounting.
This should provide plenty of light with the appropriate ballast. Probably in the 75K lumen range. |
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| woneill |
jjasniew,
Why don't you use it? If you have any hardware to mount such a creature, I'm sure you would have the best light source out there...
I have been checking out the Osram site regarding their 575 Watt bulbs, as apparently used in the Dukane 680 and Elmo 305, and they appear compatible with standard (M59 ???) 400 Watt ballasts when paired up with a "pulse start" igniter.
With the electronic versions of this ballast (higher frequency and better line regulation) the bulbs even give longer life than when used with their normal ballast...
Bill. |
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| noodles |
I'm giving up on my nView Spectra C. I contacted the eBastard but he never replied. When I power on the unit, it comes to a blue screen that reads, "nView Spectra C". Undream has reason to believe that I'm using a bad cable. It's the '92 model with Analog input, DB9 EGA input, Monitor out, Accessory jack,remote, and power supply.
Here is the link to the eBay auction including pic
As you can see, I bought it for $39.99 and it came out to be $55.99 including shipping. If anyone's interested, please tell me. Maybe you will have more luck than I do. I don't have the patience to go buy brand new cables. I'll part with this item at $25 + whatever the shipping costs. I'm not here to rip anybody off. It's just that it doesn't work for me. And I need a model with composite video-in. If you're not satisfied, you can try as I did and offer it to someone else to try out. I really don't want to rip anyone off. I'm a nice person. Unless my seller magically replies to my emails, then this offer will still stand. |
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| MikeZupcak |
I really need to know if a 7" Widescreen LCD will work. Im also looking for bulb recomendations. I really don't want to exceed 400 dollars on this project and the LCD is already 200. If the 7" widescreen LCD is too large, does anyone know where i can find a smaller 16:9 LCD? I REALLY need help on this. Also: does anyone know what kinds of lenses i will need and have links to a site that sells them. Thanks!
Also, this is the design i plan to build my projector by
http://www.audiovisualizers.com/madlab/lcd_proj.htm
Scroll down to the hand drawn design. Help is greatly appreciated. |
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| fender4 |
MikeZupcak,
I think you might have a hard time finding lenses to work with the 7" LCD. They would need to be at least 8" in diameter to cover ther image, and that would probably mean a custom lens=$$$.
If you would like to stick with that LCD, you will probably need to use an OHP style setup...just use the LCD like others are using the LCD projection panels. You could downsize the enclosure by "folding" the light with mirrors.
It might be easier/cheaper to just go with a projection panel, but the 16:9 size is a nice feature to have. You could always black out the top and bottom bars and create a 16:9 LCD from a projection panel like posted earlier.
That's just my opinion. ;) Good luck with it!
-f4 |
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| MikeZupcak |
Im still looking into that 7" 16:9 LCD screen
Any way i could build an LCD projection panel using the aforementioned LCD screen? |
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| tomithy83 |
ok ihavent made a projectos yet but why wouldnt you be able to use a 16:9? unless the ribbon cables prevent you from removeing the backlight and everything behind the lcd itself there shouldnt be a prob
$200
you can get panels on ebay for around 50-100 |
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| daveb |
It's me, Dave. You may have gleaned that I'm a few steps behind you, but following directly in your footsteps.
I picked up my 400 W MH ballast/bulb/kit a couple of weeks ago, and wired it up yesterday, while the kids were watching "Shrek".
A couple of questions, for you, or anyone else, who knows:
1) the wiring diagram that comes with the ballast doesn't give any indication of what to do with the Ground wire from the 3 lead power cable. Black goes to the 120V wire, White (neutral) goes to the common, but what about the ground wire? I'm no electrical Engineer (Truth is, I'm a Mechanical Engineer; that plus $1.25 will get me a cup of coffee!) but I'm guessing that I should attach the ground wire to the metal bracket that holds the ballast. Comments?
3) The GE bulbs have a number of letters that may follow the 400W indication. Sometimes U, sometimes H, etc. I *think* these indicate the acceptable burning positions of the bulb: H for horizontal, V for Vertical, U for Universal (that is, any position is ok). IS this correct? I noticied that you mounted your bulb vertically in your early incarnations, but seem to have changed the orientation in your latest casing.
Thanks,
dave. |
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| Undream |
yep, your correct on the letter indicated burn position. I have a MH400/U
U: universal, any direction
BU: base up, which means, hung upside down
BD: base down, standing on its base
H (or HOR): horizontal.
As for the ground on the three prong? I didnt know what to do with it either, so, I just didn't hook it to anything. hehe. Someone please tell me if that is bad. |
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| tomithy83 |
in most eceltric apps it wont hurt if the ground is not connected its just a precaution
should be fine but im no electrical Engineer |
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| Duo |
| Sorry to but in on you guys, but what do you consider to be a really BIG size for a projection screen?? Mine is 7' tall and 9' wide, hows that for a screen?? |
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| djquick_silver |
| I was looking through links on this site the other day and ran across one of them that said that the ground (green wire) should be hooked up to the ballast casing i wish i could remember what the link was but since i've been doing so much reading lately it's buried somewhere... all i remember is that it had something to do with Icecap?? ballasts for MH bulbs ... hopefully this helps or maybe youi could find the link again they had a full wiring diagram for MH bulbs and ballasts. |
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| daveb |
In digging around the web, I see references that both the reflector and the Ballast base should be grounded.
So far, I haven't got a reflector, so the base seems to have been a good guess.
If anyone is in the know, I hope the knowledge will out. There seems to be some advantage to grounding aside from safety. I've seen reference to the fact that is takes out some interference; I wonder if it'll cut down on the hum that the ballast makes.
Probably not...
dave. |
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| the whinner |
hy, i am new here and i need help from german DIY-ers!
can some of you tel me what is the german word for page magnifier lens / fresnel lens ( 8 x 11 inch or bigger )!
i live in Yugoslavia and there is no way to find fresnels here, but i have some friends in Stutgart, Germany and in Wienna, Austria, who could buy them for me!
the only problem is that i dont know what are they caled in german!
or can you give me some links or adresses in those towns, so i could tell them where to go!
THANKS!!!
P.S.: you might find this link useful!
http://www.physics.umd.edu/deptinfo...ecdem/l7-33.htm |
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| biteon |
pink line is the air
air gose in through the fans than it gose through the tubes than air gose through the side holes in the mirror reflector i made than out the front of the reflector (holes) than hits the low-e glass then comes back to the light and out the hole where the light is going in to the reflector then the air gose out the exsost hole.
sorry for the run on sentance.
like this your not circulating hot air,or messing up the reflector, and its cooling the reflector, glass,and the bulb. i hvent tested it because i need to mount the bulb and order the low-e glass to finish my projector.so im still not positive this will work, but it sounds to me like it just might.
yelllow line is the light
this is what im hopping will work,or else im back to step #1. as long as the light gose some what forward and there is a fresnel right at the end of the reflector to catch all the light coming out of the reflector than the fresnel will send the light in one direction. i think it just might work see my picture. if you guys see a problem or have a queston, just tell me .it would help me out.
thanks & later.
:D :D :D :D |
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| Duo |
looks like a great idea to me, that's exactly what I plan to do!
I hope a 400w halide produces enough lumens, I know it's sure darn bright in the open room as it is!!! |
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| MikeZupcak |
Biteon, i saw your diagram and have a few questions:
Where did you buy your bulb? What size and model LCD are you using and what are the blue lines and the green line in front of the light. |
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| woneill |
MikeZupcak,
Re your 7" 16:9 screen idea.
1) Check out whether the pixel res is RGB triplets horizontally, or each LCD shutter (one each for R, G and B). Most small video panels are quoted with a shutter res, and must have their horizontal resolution divided by three to get a reasistic figure.
2) If it has the correct resolution, then you could probably use a higher quality fresnel as an intermediate collector lens between the panel and the main objective, or go the OHP route.
Either way, you need to get all the light coming through the panel to go through the main objective in a controlled manner - otherwise you will lose brightness and/or quality.
The best bet is to use an objective lens that is bigger than the LCD panel - but there are very few 7" objectives around (the fresnel arrangement is a compromise on this). You COULD explore the route of using a 5" panel with the same type of 5 7/8" PCX used by Undream...
Bill. |
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| biteon |
the 2 green lines is the low-e glass which is two pieces of glass and some sort of gas in between to filter hot air . i desided that it might separated the box in two parts 1 the hot stuff side with the light and any thing else that can withstand alot of het and 2 the side that can not have to much heat forinstants plastic fresnels and controler boards and lcd polarizers etc. . but if the cool side of the separration is still to hot im planning to put a small fan.
the blue lines are the two fresnel lenses(plastic for now)one to capture all the light from the reflector and the other to condence the light so most the light is on the lcd and not all over the box walls being wasted.
the lighter color yellow after the low-e glass is colder light sence its being filtered from the low-e glass. and the box under the fresnel lenses is a metal box i made to cover and help keep the lcd controler chip cool i had a (heat problem there not to long ago),it also make it easy to separrate the box more with the fresnel lenses and wood.
im using a 5.6" car lcd color with remote and it has 700x900about res. and bought it at e-bay from some company name starvision for about $124. with out shipping etc. . the bulb is a 400watt metal halide ms400/u i think and i bought it here in my home town at a electrical store called "electrical distributers" or something like that. ive been having cammra problems so its been hard to get pictures ,ive been drawing most of my work. |
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