| slize |
may be i got some things wrong; espacially this "lol"
(what means "laughing out loud")
and you said that several times, so i felt attacked...
i am in this forum since the first post of the first thread when
vince aka vdi_nenna posted his ideas of LEDs with panels...
Since then i have read EVERY single post, so don't tell me to read this forum...
yeah sony and so on are using small panels and small bulbs to make their projectors portable; which has nothing to do with the light out-come (it complicates a good projected picture because of the optics but thats another theme) mainly the bright light comes from the special bulbs they have (that's the reason it costs 100 of dollars to replace them). they have bulbs at 250watts but with 100000 of lumens...
but my projector doesn't have to wheigh 6 pounds it can also weigh 60 pounds if only the quality of the picture is good...
go and read some pyhsics books about lumen, lux etc. and you will see that my theory is correct... |
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| slize |
hi rapsac,
the panel has TCO 99. i think at this time all response times where at about 35 ms (i hope so... :) ) i'll see when i have it. but on my first projector i had a MaxData PC Monitor TFT a it came with TCO95 and worked well too... then i got a MaxData TFT with TCO99 and it worked great (this is what i use now)...
the point with the panel is too bis for a fresnel is solved through an fresnel from an overhead projector, which is big enoug to light the whole 15" panel.
That's the main reason why i bought a 15" TFT with sxga. I can be sure the fresnel will light up the whole thing.
best regards
slize |
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| slize |
| my bulb is an OSRAM Powerstar HQI-TS 400W/D with 45000 lumens and 9000h life time. actually it is an HQI bulb which is mainly egual to MH bulbs... |
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| ace3000_1 |
oh dont u worry slize ive done my theory ive done my physics and reading on light, maybe u ought to read up on what u can do and how to control light, and the main reason sony and the other pro's make projectors so small is not only because of them being portable but also no one wants a 60pound box in the middle of their room not to metion a 400w current draw, if u did some research on projector bulbs they are not so special eh? its the size of the bulb that matters to them and the output, and buy the way a typical 250w projector bulb puts out a max of 20000lm's, and they only add a small amount of mercury to the gas to get it that bit brighter thus costing them life and also over current, the main reason u pay a high amount for the projector light is also the reflector, its not just an ordinary reflector no more, its a work of art and a filter, so why dont u read up and email around and maybe u might learn somthing for yourself instead of just by whats going on in here and have some respect while your at it, oh and dont u worry about respecting me slize im leaving this video forum as far as im concerned if people dont want to listen, beleive in things that have been practised not just in theory but practically aswell well im out, im done with helping jelous ****heads like yourself who instead learn' pic and acuse me of being a know all, sorry but any info is good info when u are learning and if u cant hack that good bye, another thing i have never posted somthing i have never tried or hasnt worked, the only thing i posted that i didnt try was about ohp"s and condensers, cruser did that at the exspence of my help wich he is greatfull for and he conducted the experiment i told him, it helped me and it helped him, i beleive that is called coperation and helping the other out somthing u have yet to learn, and i dont care how long u have been in here for it doesnt make u right! eh?
anyway im gone with the rest of the pro's who knows whats best see ya all |
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| prjctr_builder |
you are a noobling who doesn't know S*&T and trys to convine us all of your ingenuity. I am sorry, but ACE knows 10000 times more than you... and because of sorry noobs like you, pros leave this forum and it makes others quit building their prjectors. If anyone had to go from this forum, ACE would be the last one on the list....
:( |
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| Negative Design |
:bawling: :bawling: :bawling:
Hey Ace we're gonna miss ya buddy:bawling: :mad:
I bet property is behind this all:scratch: lol
well im leaving too (if anyone cares...lol)
im kinda bored with DIy.. plus my ISP is going off soon..
WE SALUTE YOU ACE!!
save me a kangaroo ol' bloke ...hehehe I'll c ya on yahoo:cool:
C U NEXT TUESDAY BUDDY! |
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| slize |
i am sorry to see you leave... honestly ...never meant to hurt your feelins bro'...
too bad i cannot profite from your help anymore...
i never doubted your thoughts but HOW the **** can get an sxga projector if not using an 15,4" TFT??? isn't that the best way yet??? any ideas ace??? |
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| slize |
what the **** is wrong with you??? i am NOT telling everyone MY idea is the best way and everyone has to follow me... i am NOT even saying my projector is better than ace's... the opposite is the case, i think ace's projector is great; because of the design and the wheigt. it's the best projector this forum has brought out... all i am saying is I want a projector with sxga resolution, in my case for the price of design and wheigt... i wish i could built a projector like ace's with an sxga resolution, but i didn't get any help for this, all i got was critc "how dumd i am to use a 15" tftf"... thanks ace... but i don't know 5,6" tft panels with sxga...
i never told ace he should **** the **** off, the was his own decision; i think he likes *****ing around a bit...
i am just presenting my idea and were attacked for that even from you; we can compare result sas soon as i am finished if you like to, but you won't see any differences... know you are asking me "why do you build a projector with sxga then, if there are no differences?" my answer is: "for me!" so that i can say i have built an sxga projector; u got that?
my appologizes go out to ace, because of my bad english understandings... |
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| slize |
| i am working right now on a light unit with a big reflector and my aim is to run it withou a fan and not to come over 45°C... i thought to use mirrors, will that help? what do you think? |
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| lincoln |
hey there. what type of projectors are you guys using?
i have an old slide projector, it works quite well. i was wondering if i could do something similar with it?
it dosnt have a round thing with the slides.. it has a thing that you push in to use only 1 slide.. loading manually.
if i could do this, would i need like a 1" lcd to put where the slide goes? or could i somehow make it so i can use a 5" or larger lcd?
thanks. |
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| lincoln |
thats just want i need! but i live in australia and thats on the american ebay :(
if i can obtain one of theese, do you think it would be worth doing?
i mean because the lcd is so small would it still look good on the wall? |
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| slize |
even if u will get it, you have to know that no one of this forum tried to tak ethis thing apart yet. no one even tried this thing at all. so there are no informations about the response time contrast etc... all i can say from my experiences is, that those little thingies don't work well... to low resolution, but i am taking this real high to 1280x1024 with an 15" TFT Monitor...
the resolution is 112000 pixels, which means 40000 dots. now imagine your tv has 307000 dots (640x480) lines wich is NTSC; don't know what they have in Australia...) so think about blowing up your tv to an projected picture on the wall with one tenth of resolution and ask yourself if this would be good enough...
in my opinion, you need at least 960x240 pixel, which would be 320x240 dots and which would be 78000 dots
but for a try it is surely worth it, especially for that low cost... so if you try it please let me know your results... |
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| Mavmesa |
While it is true that higher res at the same screen size will block more light, it should not be signifcantly more than a XGA.
You may get some corner cut on the fresnel not projecting through the tft panel's corners. I get just a touch of that wiht my 15".
Go for the higher res. I do not project more that 75" as I want to keep the "screen door " effect from beng noticeable. A higher res would allow me to project a larger screen while still minimizing the "screen door effect".
As a 15" lcd panel user, I support you, slize. Keep on going!.
Ken |
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| slize |
| :) finally some positive response |
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| lincoln |
i am currently the high bidder for the same one on the australian ebay!
but the reserve is not met... i think the reserve might be set at like $ AU 100...
would this still be worth it? |
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| prjctr_builder |
Well, you'll be the one to tell us if it is worth it, once you get it and test it.....
good luck:) |
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| slize |
received my nec TFT today; this thing is awesome: can't wait to take it apart an build my new projector; 15" but 1280x1024 awesome and no shadows at all, the response time must be something like <35ms and the contrast isn't bad at all; it's the same like with my 300:1 panel. but you recognize at once the resolution difference especially when watching football or tennis basketball etc...
this time i'll built a portable "compact" projector sxga projector. |
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| Video Freak |
| Slize hwere did you find a sxga 15 " lcd? C mon Spill the beans!!!!!!!!!!!!!:goodbad: |
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| prjctr_builder |
does anyone know where i can get a complete lightsource for my projector? preferably between 250 and 400 watts and about 4000-4200k temperature. i need the bulb and the ballast kit.
thnaks for any info
good luck all:nod: |
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| Video Freak |
| Hey Builder I just ordered a 250w HQI ballest light and endcaps from www.yellertwoproducts.com and it came within 3 days and was packaged really well I would recomend them. it was 159.00 plus shipping, hope that helps. |
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| Mavmesa |
Slize
Let us know how that thing comes apart and how the boards are connected.
Mavmesa |
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| slize |
i will...
as soon as i find the time to take this apart... with pictures hopefully... |
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| prjctr_builder |
$159.99 is way too much for a lightsource that will be installed in a DIY projector, is it not?
i am watching a few ballasts on ebay and i am not planning to pay more than 60 for both ballast and the bulb. SO far i got a 250W MH bulb for $20 from ebay, brand new, 22000 lumens, 4200K. so that leaves me with $40 for ballast.
good luck all:) |
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| Magamus |
Slize,
Yes, please let me know how that NEC 1525 comes apart.
Guys, I would REALY appreciate some help here. I tried using a Samsung Syncmaster 15" AND a NEC 1555v also 15" and they both had a dang ribbon cable conecting two cards behind the freaking screen:( I cannot use either one as it covers up too much of the screen. btw the Samsung is a bad **** lil monitor (the best screen I have seen, as far as all of it goes). But please help me on this (as I am driving myself mad, lol) and let me know of any type of LCD monitor displays you guys have used (that were easy to work with once taken apart and are still for sale, stores or e-bay:)) I would very much appreciate it. Thanx to all in advance. |
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| Mavmesa |
I don't know anyone in Ohio that uses the word "****".
I have had great success with the NEC 1545V. What is the LG model number on the internal TFT module on the 1555V?
Mavmesa |
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| Magamus |
Mav,
Dunno. My friend is the one doing it (I bought the stuff and I am doing most of the research, but I have never used soder for anything) yes, I use "****" all the time, lol. btw, I can't find a NEC 1545 for sell anywhere (even ebay) do you know of any others for sure that work? |
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| Specter |
Hello all.
Just stumbled into this forum and thread a few days back.
Interesting ideas here. This subject has been of interest to me, on and off...for some time now...but I must admit...I haven't yet tried to build my own, due to excessive cost.
Anyway.....
After reading most of the individual postings here, I thought I'd add my two pennies worth.
Some info and items readers here might find of interest:
Scientific Americian Magazine, March 1991, vol 264, #3
page 76 "Non-Imaging Optics - Funnels for Light can concentrate solar energy to supersolar intensity"
The principals might help with light collecting problems I see mentioned here...
Scientific Americian, "Amateur Telescope Making, vols 1, 2, & 3", Albert G Ingall Editor
- it's not just about telescope making...good optics info, theory and DIY how-tos -- no ISBN number
and finally...
IBM made a Thinkpad laptop, models 755CV & 755CDV.
These particular models are designed to be used as normal laptops, but also can fold open flat, after removing the LCD panel back cover...for use in an OHP.
Downside...640x480 pxls...low colour palatte...and 486/Pentium classic (upgrades) CPUs. Obsolete.
Hope this info proves useful.
Specter |
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| echow87 |
| quote: | Originally posted by Magamus
Mav,
Dunno. My friend is the one doing it (I bought the stuff and I am doing most of the research, but I have never used soder for anything) yes, I use "****" all the time, lol. btw, I can't find a NEC 1545 for sell anywhere (even ebay) do you know of any others for sure that work? |
Theres a couple on ebay. Just search for NEC 15", do not type in 1545V because it will not narrow the search for you. |
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| Magamus |
Mav,
Look at some of my other posts. I finally got it:) I used the Samsung 150MP and it only had one card on it (which is out of the way) and one sammler card hooked to that card (for menu selections, but is is out of the way too) came out great! Thanx for your willingness to help me:) |
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| Mavmesa |
That's GRRRRReat!!!.
As for me, I am happy with my 1545. Now I am just waiting for my new shorter length fresnel lens from Alan to increase my brightness. The shorter focal length on one side lets it capture more of the 400 W MH bulb's output and send it through the lcd panel. The 13" fl drops to 8" fl on just the bulb side. I will be able to shorten my case as well. :nod:
Mavmesa |
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| prjctr_builder |
Where did you get the 13" fresnel lens? Who's Alan?
thanks |
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| Wes Marquenie |
| I think he's talking about focal lenghts and not the fresnel size. |
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| Magamus |
Mav,
Can you elaborate on that a bit more for us? Do you have to crop the image at all? My LCD does not allow me to crop the screen image:( How much does this cost and where can we get one?
Jacoby |
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| Magamus |
| Check out my new thread on a polarized film sheet. You guys might like it.:nod: :nod: :nod: |
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| verbose mustafa |
I just bought a CMV 1515 LCD monitor! $239 shipped and brand new!
Resolution: XGA
Colors: 16.7
Contrast: 500:1
Pixel Pitch: 0.297 mm
Responce Time: 15 ms
It has a stand alone power supply so there is no ac power going into the monitor itself which i like. Should be a very clean strip to take out the lcd. There will probably not be too many boards in there layin around.
And get this! It Has two 1 watt speakers :rolleyes: !
I figure at $239 this is a pretty good deal for the specs. I'll keep you guy informed as to the ribbon cable situation. It's really taking a long time to get my lexan glass projector built lol. Least i'll have a good display in the meantime. |
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| Mavmesa |
Alan has a web site called www.diylabs.com and sells alot of stuff that we can use. His prices are cheap considering that all of it is new, not ebay. Many people here have dealt with him, but many get frustrated with his long fulfillment times. He found the new fresnel lens for us and is the only source that I know that has it, so I wait patiently for it to arrive. He actually has enough parts that he can supply everything in kit form except the lcd itself.
Ken |
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| prjctr_builder |
omg, it took me about 10 hours of work today just to instal my lightsource into my projector's enclosure. I finally recieved my ballast on Monday and was making plans of my projector to be... I ordered 2 ballasts from ebay, a 250W ballast and a 400W ballast. They both cost me about $60 and the 250W ballast works pretty well. They are both new. The bulb that i got off of ebay, 250W MH 4200K and i think 22000 lumens also keeps me very much satisfied *knock on wood*. As to my LCD, i am using viewsonic 15" XGA lcd. it came apart alright, but the ribbon cables are a little flexed in my construction. About 30 minutes ago, i tested the whole "prototype" that is for now held together my duct tape, and still, i got a bright, sharp and very good looking image. I did not get a chance to connect it to my computer, but the BLUE color in lcd menu, was the sharpest blue color i have ever seen. It looked about 5-10 times better than the color i got from dukane quantum and Sharp QA-2500. I will work super hard tommorow to try to install the optics and the LCD in place permanently...
that's all for now:)
good luck all |
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| echow87 |
| quote: | Originally posted by prjctr_builder
omg, it took me about 10 hours of work today just to instal my lightsource into my projector's enclosure. I finally recieved my ballast on Monday and was making plans of my projector to be... I ordered 2 ballasts from ebay, a 250W ballast and a 400W ballast. They both cost me about $60 and the 250W ballast works pretty well. They are both new. The bulb that i got off of ebay, 250W MH 4200K and i think 22000 lumens also keeps me very much satisfied *knock on wood*. As to my LCD, i am using viewsonic 15" XGA lcd. it came apart alright, but the ribbon cables are a little flexed in my construction. About 30 minutes ago, i tested the whole "prototype" that is for now held together my duct tape, and still, i got a bright, sharp and very good looking image. I did not get a chance to connect it to my computer, but the BLUE color in lcd menu, was the sharpest blue color i have ever seen. It looked about 5-10 times better than the color i got from dukane quantum and Sharp QA-2500. I will work super hard tommorow to try to install the optics and the LCD in place permanently...
that's all for now:)
good luck all |
Wow,
Awesome, you say you got both of those ballast for only $60? If yes, good find. |
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| verbose mustafa |
| The projeciton lens will project an image over 10 feet at only 37 inches! What a zoom lens! Don't worry though, it will only work with a 4" lcd panel :(. |
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| chbright |
| why will it only work with a 4" panel verbose. if u put the back of the lens where the fresnel's foucus point was wouldnt it work. |
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| cohort36 |
OK, I know I'm new posting here, but I've read all of the original thread and am most of the way through this one. I have searched this one through current postings for LED related posts, and have read the seperate LED thread.
That said, I am wondering about the Luxeon Star (1W) LED's. Everything I have seen has ruled these out as too expensive per lumen or not creating enough lumens. The specs list these at 25 lumens. I think that a higher percentage of the lumens would be usable as compared to a MH or other bulb, because of the fact that the light is collimated (by the optics) and is perpendicular to the LCD. Secondly, if price were not an issue, do you think these would be a viable option? I may be able to pick up a LOT of these very cheaply.
Any feedback or ideas? |
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| echow87 |
| quote: | Originally posted by cohort36
OK, I know I'm new posting here, but I've read all of the original thread and am most of the way through this one. I have searched this one through current postings for LED related posts, and have read the seperate LED thread.
That said, I am wondering about the Luxeon Star (1W) LED's. Everything I have seen has ruled these out as too expensive per lumen or not creating enough lumens. The specs list these at 25 lumens. I think that a higher percentage of the lumens would be usable as compared to a MH or other bulb, because of the fact that the light is collimated (by the optics) and is perpendicular to the LCD. Secondly, if price were not an issue, do you think these would be a viable option? I may be able to pick up a LOT of these very cheaply.
Any feedback or ideas? |
Heh...
LEDs' will not work. They arent bright enough. If I were you, just get a MH ohp on ebay or get a lighting kit, maybe a 250 watt double ended? |
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| verbose mustafa |
LED Stands for:
(L)ittle (E)xpensive (D)im |
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| cohort36 |
| So are there any specific suggestions/recommendations for using MH? Is 250W (assuming a decent reflector and/or condensor setup) enough for a 5" LCD? Or is 400W the way to go? Is the only choice those big 8" M59 bulbs, or is there anything smaller? I've seen some double ended bulbs that are smaller, but I haven't found a place where I can get a setup for that for anywhere near a decent price. Thanks again. |
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| prjctr_builder |
I have been building my projector for past 2 weeks now, and i got LCD, and lightsource insytalled already in a pretty nice, but kinda big box. I am about to install LCD controller and fans in the box and i will be all set. Opps, almost forgot, i need to attach my objective to, but it is kinda tricky, sicnce i wanna have a moving objective to adjust focus on my projector. I am running a 250W HM bulb, and i am testing my setup on the white wall about 3 feet from the objective. eventually, i will have my screen about 15-18 feet away from the objectives and that is what worries me. So far, the brightness is perfect, but what will happen when i move my projector 5 times further away from the screen? Will the 250W bulb provide enough light?
P.S. I built a very nice reflector from sheet of steel tha ti got from home depot...
:( |
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| Mavmesa |
prjctr_builder
Here is how I got my triplet lens fixed in a lens board and attached that to an old OHP focusing arm.
 
 
Normally, I have a cloth shroud that covers around the lens board, almost like a bellows on the old photographic equipment.
Mavmesa |
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| pashiran |
i knew this site just a minute ago :)
Im Korean and forgive my poor English plz.
Korean started DIY projector about 1years ago.
but made good projectors many
just come and look.
http://club.wassada.com/diypro/iclub.asp?code=3
that link is pic board. of course language is korean but you can see pics. ;) |
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| prjctr_builder |
I got my projector about 90-95% completed, and i have encountered a problem that i knew i could peotentially have. Basicaly, i have a good quality, contrast, brightness and sharpness, but my projector works like a rear projection type. It displays top and bottom correctly, but it shows left side on the right side and right side on the left side. What i need is someone to tell me how i may be able to fix that problem... If there's software that does that, let me know, if there's a video card that dies that let me know as well... If there's any way i can flip the screen across the y-axis let me know. Physically flipping the screen is not an option... i will not be able to fit all the components into the projector and i will need to extend the cables, which do not want to do. please help me, anyone...
:(
aleksey |
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| Takusama |
| A mirror perhaps? :scratch: |
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| Mavmesa |
I ran into the same problem. I was, however, using a doublette lens that had a mirror. As soon as I changed to a inline tripilett, the problem solved itself.
It seems that NVidia drivers can do just about anything, except flip the x or y axis. I do not know of any solution other than to put a mirror at a 45 degree angle in front of your projector.
Ken |
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| sadd3j |
Just in case you're using an ATI card.. the Omega drivers can flip/rotate the display for any orientation.
-rep |
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| prjctr_builder |
ok, here's what i did...
I went on NVIDIA website, got the tech support number and gave them a call. Some newb answered my call and for all my questions and requests he said either i dunno or i have to check. So i just hung up and called ATI as it was referred to me by him. ATI person did not know wack either, but after he transfered me to the "TECH SPECIALIST", i got and answer. Turns out, the card that does the flipping of the screen however i want it, costs roughly 400-450 US$. After a minute of analyzing what just happened, I went downstairs, took the LCD and controller boards out of the projector, and after 5 hours of non-stop work flipped the screen exactly the way in needs to be. i figured that what i did, was worth 80$ an hour, so i think it was worth flipping the LCD manually. I have to tell you that i dunno how the ribbon cables did not rip, becasue i have to bend it at almost 90* angles and dropped controller board while it was connected to the screen. Anyways, theoretically i solved the problem, but i need to test it tommorow since my brother too the power cable upstairs for some reason...
thanks guys for your input...:) |
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| prjctr_builder |
IT WORKS!!!
i will include the pictures within 2 or 3 days
yessssssss |
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| Neversaid |
It works...!!
Hi all!
In the end i managed to get a panel from the US ! I've got i thin a lot of luck for all in one i paid 60$ for my whole setup. I've also buyed a proxima ovation 820C for comparsion.. But if i compare:
ASK Impact 21 <> Proxima Ovation A822C
Colors:
I'd like to say that the ASK is the better on.. I say the image is clearer and naturally, on the Proxima the picture is sometimes a little bleached...
Reactiontime:
Hmm the reaction time... In the Eraser Scene with ( with Arnold Scharzenegger) the great showdown in the port id'like to say that on the Ovation and on the ASK no Noticeable blur is, but if you compare dark scenes, the ASK have got an sharper and colorfuller picture.
Id'like to say .. all in one the ASK is a little bit better not much but a bit.
One pity is, that the ASK 21 has got no Composite Input.. so you can't watch tv without a linedoubler.. but i've got a tv card.. no problem :devily:
some technical Informations...
ASK Impact 21
==========
640x480 (800x600)
2.1 mio
VGA only
remote control
40ms
June 1994
Proxima Ovation A822C
================
640x480(800x600)
2.1 mio
VGA, Composite
30-50ms
1994 (?)
Overhead :
========
old 3M from school with 300W Halogen bulb..
watchable with a little bit daylight.. night's watching totaly ok
I replace to bulb with an HQI 250W soon...
So on... i post some results this evening..
Greets
Bernhard |
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| prjctr_builder |
guys, i am in trouble...
i got a good image from my new projector and everything workes just fine, except, i only get the desired screen size about 5 feet from the projector. this is bad because haveing an 8' by 6' screen 5 feet in front of you doesn't look that good and almost gave me a headache. i am using an objective lens from dukane 4003 overhead projector (it says 327mm on the objective), and because of that the objective throws light out at a large angle. I need to have the same 8' by 6' feet screen about 15 feet from my projector. any ideas on what type of objectives i should use? or is there another way to solve that problem.
thanks guys (and girls perhaps?) |
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| proto5 |
Ahhhh.....
Grasshoppa seeking Holy Grail of DIY projector building.....
Problem has not been solved for as long as I've been around this forum. |
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| cohort36 |
prjctr_builder:
I'm not entirely sure what's going on with your objective and throw distance/screen size, but I have a couple ideas. Even if none of them are right, I'm still interested in what's going on, because I'm about to order an objective for my projector as well, and don't want to make the same mistake.
Using gunawan's spreadsheet calculations, I entered the following data:
LCD diagonal: 15"
Objective focal length: 12.87" (327mm)
Distance to Screen: 180"
LCD to Objective distance: 13.86" (autocalculated by spreadsheet)
This produced a screen diagonal of 116.88", which is in the ballpark range of 120", so that objective should work, if the LCD to Objective distance is correct. I played with the numbers a bit, and at a distance (to the screen) of 60", if the objective is only 4.5" from the LCD, you will get a screen diagonal of 120". I don't know your exact setup, but based on these numbers, maybe your objective is too close to your LCD?
Using another formula for calculating the optics that I found in this forum (or maybe it was part I):
D = F * (S / A + 1)
D: Distance to screen (180")
F: Focal length (12.87")
S: Screen diagonal (to be found)
A: LCD diagonal (15")
This leads to S = 194.79", which doesn't match up with what you've seen or gunawan's spreadsheet. If you set S = 120" and solve for F, you get 20", which means your objective is too short. Or, if you set S = 120" and leave F =12.87" and solve for D, you get 115.83", or roughly 10", not the 15" you're shooting for.
What does all of this mean? I'm not sure entirely. I have a feeling that your problem (and all of these contradicting calculations) stems from the fact that the focal length of your objective is smaller than the diagonal of your LCD. I thought that it had to be at least as large as the LCD.
Sorry for the long post. It may be completely useless, but maybe there's a couple of things to try (LCD to objective distance, objective focal length). Keep us posted. |
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| verbose mustafa |
| If I'm right from some hours of research, the focal length should be the size of the lcd diagonal or slightly larger. That is wy we cannot use 35mm zoom lenses. |
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| prjctr_builder |
my projecor works great if:
distance from LCd to objective = 16"
distance from objective to the screen = 80" (this is where i can get a good focused 6' by 4.5' feet image ont he screen)
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this gives me a good focused 90" image 6.5 feet from the objective.
thanks guys |
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| prjctr_builder |
I did a little research using a nice little program that you can find here http://www.opsci.com/index.asp?page...hCalc&exten=htm
I decided that to have a perfect theater environment, i will need to have my screen 12 feet fromthe projector.
Here's what i got from my focal lenght and al the other stuff. Let me know if this is correct, and also where cal i got objectives with such focal length?
thanks |
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| afan |
| For projection purposes we would need zoom lenses with FL of about 350..500mm. Thus, we could possibly use some telephoto optics with 170..500 variable focal length, but new ones cost like hell. It's cheaper just to buy a set of lenses, with, say, 350mm, 400mm, 450mm fixed FL and change them in projector if needed. |
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| prjctr_builder |
$189.99?!?!?! i do not think that ANYONE on this forum would be willing to pay that much money for the objective lens alone...
thanks guys
P.S.
is there a way that i can combine objecives with different focallengths to get the focal length that i need.
for example, have a 327mm objecive and add a 200mm objective, what will it give me? any ideas?
god luck |
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| cohort36 |
prjctr_builder:
I thought you were going for a 8'x6' (10' diagonal) screen at 15' away. Have you changed to trying for 6'x4.5' (7.5' diagonal) screen at 12'? Anyway, I think the ~520mm lens should work for the smaller, closer setup. (At least that value works in all of the formulas I've been using.)
As far as using your 327mm and 200mm objectives to get ~520mm, try using gunawan's spreadsheet for 2 lenses. Using those 2 focal lengths, if you placed the lenses 15-16" apart, you'd (in theory) get the equivalent of ~520mm. I don't know how well this actually works in real life, though. If you don't like the idea of that much space, try getting a couple of shorter focal length lenses. For example, (again, in theory) if you had 2 lenses with 100mm focal lengths, you could do it in about 7". |
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| slize |
here comes the dumb slize; may be you should ask genius ace for this...
anyways; here is a try to solve your problem...
the "maximum focal lenght of lense" means this is the maximum to get your picture projected in this way you want to have it.
4 rules
first rule:
imager distance twice the focal (2xf) lenght then picture wide has the same size in the same focal lenght (2xf) on the other side of the lense
second rule:
imager distance is bigger than 2xf then picture wide is smaller
third rule:
imager distance lies between focal length and 2xf then the picture is magnified
fourth a rule:
imager distance is smaller focal lenght the picture won't never become sharp
now to your problem:
i guess you are using an ohp lense (guessing from your lense focal length)
my ohp lense has a focal length of 30cm that is 1/f = 0,033 dioptrin
in my case i'll need a lense with maximum of 54cm = 0,0185 dioptrin
ok that means i'll need an additional lense that has -0,0145 dioprtin
0.033-0.0145=0.0185
tomorrow i'll go to the optiker a gonna buy an eyeglasses with -0,0145 dioptrin...
as i see your parameters are quite the same as mine... hope that helps everyone...
BTW nice program you discovered there...
i don't know if this works but i am confidently it will because i tried to build a 2 lense system with eyeglasses; it worked ok; better then the fresnel lenses but worse than the ohp 3 lense systems...; but if you combine the 3 lense system and the single eyeglass may be that makes a clear sharp picture with the size you want...
hope that helps everyone; i will try it in about 2 weeks
slize |
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| slize |
and LOL 190 bucks for a lense we don't know how/IF it works, that is WAY to much...
:))))))))))))))))))))))))))))))
in my opinion it won't work, because the imager wide has to be the same as a camera film; and an lcd of this size with good resolution would be great for all of us...
with oph lenses it is different, they are constructed for din A4 sheets, in wide near to our LCDs...
slize |
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| prjctr_builder |
so what lens will i need to purchase in addition to my 327mm objective so that my max focal length would be about 521mm?
thanks slize |
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| thermopyle |
| so you need a -610mm focal length at 100mm from your 327 to give you 520.81mm total focal length. I guess that means you use a convex lense but I'm totally new to optics. |
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| prjctr_builder |
all this S%*T is confusing... i cannot seem to find the right way that i can solve my problem.
theoretically, using slize's way of solving for the dioptrin, i will need a lens with -0.011391 dioptrin. please correct me if i am wrong, slize.
but at the same time, having my 327mm objective and adding to it a 200mm lens 400mm away... will give me about the same 521mm final focal length.
Can sone one who's good at this tell me if i am on the right track or am i just getting deeper and deeper in the forest of confusion.
thanks guys |
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| slize |
your dioptrin sounds right...
1. divide 1 / "focal length of your existing lense" and you'll get the dioptrin
2. then divide 1 / "max focal length you'll need"
now "1." - "2." = something negative, that is your dioptrin of the additional lense
you'll need a konvex konkav eyeglass...
because a bi konkav eyeglass is very expensive and will paralell the rays, so you won't never get a sharp picture.
just ask for eyeglasses for farsightedly people, they have to be cheap at this low dioptrin...
important: in my conclusions, you'll need to add the additional lense as close to your ohp lense as possible, that means NO distance just put it right in front of it. Becaue if you have more lenses fixed togehter closely you count it as one. but if you have distances between it, you'll need to count every single lense and that is too much work :) (at least for me) |
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| slize |
thx verbose,
great programm too...
@prjctr_builder:
you can try your results with the program of verbose mustafa and you'll see; if you leave the distance at 0 the focal length will come out just as youwant it... |
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| verbose mustafa |
| No need to thank me. I simply host it for download. "Gunawan W." made it :D. |
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| cohort36 |
A few pages ago, you mentioned you made a pretty decent reflector from a sheet of steel. How/what did you do? I've got the same bulb as you, and am thinking of just bending a length of sheetmetal into a semi-circle, so that the bulb runs the length of the metal. Kind of like this:
(o
( is the reflector, o is the bulb. Both are running into the screen.
If that's not enough for me, I'm thinking of adding a couple of other pieces of metal to the ends, to try to focus more of the light back in.
Is this similar to what you did? Or what worked for you? |
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| slize |
HUI this site prjctr_builder discoverd is FANTASTIC!!! I found out that i can zoom in and out the projected picture by reducing and increasing the distance between my ohp lense and this additonal eyeglass... i'll go tomorrow and buy that eyeglasses with the right dioptrin after some more calculations tonight...
if the sharpness is good that would be a great solution... |
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| proto5 |
Slize:
I consider the "throw distance" to be the biggest issue with our DIY projectors.......There's alot of people doing math and saying this or that SHOULD work, but I've yet to see a DIY 15" LCD/OHP projector that projects a small enough picture. My box is probably only 8 foot from the screen and the picture is like 12 foot diagonal......
IF ANYONE OUT THERE CAN SOLVE THIS....PREFERABLY WITH AN ADD ON LENS, I'D PAY GOOD MONEY FOR IT...AND I'LL BET MOST OTHER DIY'S WOULD TOO!!!
PLEASE KEEP US POSTED ON YOUR EXPERIMENTS!!! |
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| slize |
no need for money; :)
I'll do my best; i think next week i got results, but my mechanical engineering study costs me a lotta time... |
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| slize |
| quote: | Originally posted by prjctr_builder
is there a way that i can combine objecives with different focallengths to get the focal length that i need.
for example, have a 327mm objecive and add a 200mm objective, what will it give me? any ideas?
god luck |
answer: yes you can...
asuming these numbers are the focal lemghts and you put it together with no distance between it you 'l get a lense system with a focal length of 124,1 mm. that is really big magnifing lense.
the shorter the focal length the bigger the magnification... |
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| slize |
:bigeyes: after doing some more research, i think it is a littl ebit more complicated than i thought at first, but it is still solvable...
i think i have to take care of the fresnel lense too...
i wanna try not to waste any light just because of too big magnification...
i'll come up with more next week, as i sit down to think for the weekend... |
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| rmccoll |
I have the same problem with my projector as you can see in the picture my projector is close to the screen, it;s about 4 feet away, but it still shows really good. It has alot of glare but the light was on I'm going to put a light tint on a piece of plexiglass and put it over the screen to reduce glare.
That formula thats on page 104 on this board was first posted by me awhile ago, I got it from the 3M website.
And Don't Laugh At Me For Watching Power Puff Girls:mad: |
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| prjctr_builder |
most of you guys probably know how important it is to have a good reflector... when i was making mine, it took me a while, but i managed to make a VERY nice, as i personally think reflector. I have made a parabolic one and it covers the whole bulb. i have plans for it which i will photocopy and post on a website or just post a pic here. the plans consist of the left, right and the parabolic sude, it is hard to explain, but once you see it, you'll ge the idea. i used sheet of steel and the good thing is that i can solder it with a common soldering iron. i do not know if the solver will get too hot and melt if you are running a 400W bulb, but i am running a 250W and everything is just fine. I had my projector on for 2.5 hours straight today and it did not overheat at all.
My setup:
Light= 250w MH bulb with a ballast
LCD= 15" viewsonic VE150
Fresnel= DUKANE 4003 fresnel
Objective=DUKANE 4003 327mm focal length (i need 520-530mm)
Cooling= 4 80mm 12v fans (32 cfm) which all run off 9v power supply. I will upgrade to 18v power supply if i will have any issues with cooling
Screen= 6 by 4.5 feet made of snow white synthetic leather
thank you guys....
P.S.
you know what, i am gonna go and order 3 lenses off ebay with different focal lengths and play around with them, see if i can get any luck. after using gunawan's program it seems to me that we can use pretty much any lens to achieve what we want, at certain distances, that is... |
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| slize |
i ordered my eyeglass today and they told i will have it in about 1 week.
You shpuld have seen the face of the salesman as i ordere ONE eyeglass... :confused: :scratch:
so results next week; hopefully i will have finished my new projector then too... :nod: |
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| slize |
bad news :bawling:
as i experienced it is only possible to get eyeglasses in dioptrin with 1/8 steps, that means it is not possible to get a -0,012 dioptrin lense like in my case ;-(((
the salesman ordered an -0,125 eyeglass for me, but that is for no use, i chancelled the order and now i am thinking about planing my room new to get the perfect image.
You know... it the prayer doesn't come to the mountain, then the mountain must be brought to the prayer... (it is a german proverb, i don't know if it exits in english but that wold be the exact (wrong) translation) |
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| slize |
| right now i am looking for a projection lense with 380mm focal length and a diameter of at least 60mm. may be someone can help me??? best would be a three lens system... |
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| slize |
i made my calculations in the wrong units...
i used millimeters instead of meters...
but dioptrin is 1/m...
my vacations are too long... ;) |
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| slize |
ok here are my new calculations:
i have an ohp lens with a fl of 290 mm = 0.29 m = (1/0.29) 3.45 dioptrien
my object size should be 1.54 m
my room has 3.15m space for that projector thing
the distance between lens and screen should be something around 2.35 m
so my ideal lens would have an fl of 385 mm = 0.385 m = 2.6 dp
that means my adiotnal lens must have 2.6 - 3.45 = - 0.85 dp
but as i know they only have 1/4 steps here in germany that means my lens must have - 0.75 dp... (in the US they have 1/8 steps)
the distance between lens and screen is then 2.31m, the distance of lens and TFT is 0.442m and with the light which has 0.30m i am in my borders; i have 3.05m all in all and can move the projector 10 cm back for the picture to fit...
so tomorrow I'll go buy such a an eyeglass... wish me luck :-) |
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| slize |
| quote: | Originally posted by prjctr_builder
so what lens will i need to purchase in addition to my 327mm objective so that my max focal length would be about 521mm?
thanks slize |
327 mm = 0.327 m = 3.06 dp
521 mm = 0.521 m = 1.92 dp
1.92 dp - 3.06 dp = - 1.14 dp
that means you need to go to the optician and buy an eyeglass with -1.125 dp for farsightedly people (because they only have 1/8 steps in the US)
or you try to find a convex - conkav lense with - 876 mm of focal lenght...
hope that helps... |
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| rmccoll |
| If you guys need help just ask the guys at www.edmundoptics.com they can help you. I email them about this topic they gave me some info but my is for a smaller lcd and a different focal length just email them with your problem and they will help. I got my message in one day. |
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| prjctr_builder |
| quote: | Originally posted by rmccoll
If you guys need help just ask the guys at www.edmundoptics.com they can help you. I email them about this topic they gave me some info but my is for a smaller lcd and a different focal length just email them with your problem and they will help. I got my message in one day. |
True, they will help you. But you will probably end up being convinced to buy on of their products which i hope you all know are not cheap.
my point:
If you need help, just ask for it in this forum, that way we will all learn something from each other. And it will cost you nothing...
good luck all, Aleksey
:) |
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| prjctr_builder |
| quote: | Originally posted by slize
i think a found a lens for you..
http://www.surplusshed.com/pages/item/l3043.html
508 mm focal length
don't know if i got everything right, but it sounds good to my, and for 15 dollars you cant do anything wrong... |
Slize, you are my savior...
I am about to order the lens as soon as i finish typing this post.
this lens will be perfect for me....
thanks man
:nod: |
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| prjctr_builder |
| For me, the ideal distance to the screen would be 12ft. This objective will theoretically give me 11.6ft for $15... Must get it... |
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| mhelin |
How are you going to use it? Look at the picture View #2:
It's too long.
How about this?
80 mm dia, 400 mm FL (it's only doublet though):
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| slize |
i thougth about that too...
but i think 15$ is worth a try, don't you think... |
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| mhelin |
| Sure if you can unmount it. |
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| prjctr_builder |
| there's nothing really great about that LCD. It is almost the same size as my 15" LCd and my LCD has way better specs and also mine was FREE. But anyways, you can get an LCd monitor similar to mine for about 150$ off ebay.... |
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