| ap0the0sis |
daaaaaaamnnn! this thing hasnt moved in 3 days! :confused:
i guess you guys got your fingers shocked from the MH ballasts and cant type. It happens... :D |
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| Mario007 |
| I was kinda wondering too why no posts. People are just so busy working they don't have time to post. Has anyone got shocked by a MH ballast before wouldn't that be enough voltage to kill you? |
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| ap0the0sis |
probably, those things can build up a hefty charge. i've been shocked by 110V and it sticks to you for a sec or two. so i can imagine what a MH balast is capable of...
ap0the0sis |
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| gav |
i've been done with three phase :( my arm was numb for about 5 minutes!! (not to mention a helluva shock when it first happened.. :) )
it wasn't on a projector tho :) |
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| remp |
Careful guys.
We dont want to loose any of you.
BTW all joking aside safety is an important issue. Most guys if you are anything like me are so keen to get things going that sometimes the important safety issues can take a back seat. Things like no exposed live wires and using proper connector blocks to connect wires without leaving stray bits of live wire sticking out. And tape them up properly. Only takes a few seconds.
Things like that. Maybe just take an extra minute to make you systems safe because its not only you that could get a shock. Might be the lady of the house or small children.
One very useful tip if you are working on live cables or poking around potentially live wires is always keep one hand in your pocket. That way its unlikely you will get a direct electrical path between both hands. Which of course passes right through your heart. If thats too hard pull the plug and leave it right where you can see it. |
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| daveb |
Since there's a lull in productivity and we're on the topic of safety, here's a question: With one of those hulking 400W ballasts, when it's plugged in a the bulb's a-glowin', are there any components that shouldn't be touched?
Obviously, the bulb is hot, but what about the coil? Or it's block? Or the capacator encased in the plastic housing? Any of that ready to shock or burn?
I'd rather find out from you than by accident.
Thanks,
dave |
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| daveb |
If I can get a few hours in the workshop, I'm going for the gusto with my setup. I've had limited (low light output) success with my configuration so far, so I've devised a new approach (see the attached pic)
With the suggestions from this forum, I'm going to presume I can obtain parallell light from the bulb & reflector (I'm going to have to cut into the sides of the reflector bowl to allow for the bulb to be mounted horizontally. The practical upshot of this is that it;ll give some space for airflow in one side of the reflector and out the other.
Then I'll use the ohp fresnal upside down to condense the rays. I'll then re-mount the original lcd's fresnal back into place on the underside of the panel. (this is the fresnal that came with the panel inside the Telex Firefly P250.
Then on through the OHP optics/mirror head and onto the wall.
IF this doesn't work, I'll have to try the "2.5x glass magnifier infront of the bulb" method of obtaining a point source, which will eliminate the ohp fresnal from the setup.
(In desparation, I"ve started pricing the panasonic PT-AE100. My confidence is slippping. Must... remain... vigilant...) |
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| Gunawan W |
hi Daveb,
if you can produce parallel light from your parabolic reflector, according to your drawing, you don't need that 2 fresnel panel!
If you want all parallel light goes to your objective lens after passthru LCD panel, then you can put fresnel panel at 1" after the LCD (make sure fresnel has fl. > obj. lens fl.)
See you. |
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| daveb |
Gunawan,
I think I do need the fresnels, and here's why:
The reflector has a diameter of about 15", and I want to capture as much of that light as possible and force it through the 6.4" diagonal LCD screen. Tell me If I am mistaken.
And here's yet another question: If I've got to change my objective lens, I'm wondering about the 5 7/8" lens that some have obtained from Surplus Shed (which doesn't seem to be available any longer). What is its focal length, and why have I not heard about any spherical abberabtion that is supposed to be inherent to single lens setups?
And something else: People have spoken at length about the DELTA 20 CRT lens. I've found a Delta IV lens. looks the same, but I can't find any reference to it. Anyone know if it's in the same ballpark?
dave. |
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| fender4 |
Gunawan is correct. You would only need ONE converging fresnel lens (ala "page magnifier") if the reflector produces parallel rays. Two would give poor results in that setup.
I haven't been following the thread for some time now, so I'm sure I am repeating old topics...but CRT lenses really aren't well-suited to most applications. For a proven solution, look for an OHP lens, or at least aspheric lens of appropriate focal length to avoid chromatic aberrations.
-f4 |
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| multiplexor |
| quote: | Originally posted by fender4
Gunawan is correct. You would only need ONE converging fresnel lens (ala "page magnifier") if the reflector produces parallel rays. Two would give poor results in that setup.
I haven't been following the thread for some time now, so I'm sure I am repeating old topics...but CRT lenses really aren't well-suited to most applications. For a proven solution, look for an OHP lens, or at least aspheric lens of appropriate focal length to avoid chromatic aberrations.
-f4 |
Curious,
what does chromatic aberrations mean(in simple english of course)? :D |
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| daveb |
| Are you suggesting my setup would be better off like this: |
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| remp |
Multiplexor
what does chromatic aberrations mean(in simple english of course)?
Different light colours get bent slightly differently by single glass lenses so you see colour fringing on a projected image.
Cheaper OHP use a single lens but better ones use two or three lenses cemented together for colour correction. Costs more but looks better.
My OHP uses a single lens (3m 1705) and there is some aberration but you have to look real hard to see it. |
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| xblocker |
Daveb,
in this last drawing, there is a much to short FL of the fresnel.Is this really an OHP setup? If you watch the light pyramide going out of the fresnel the, apex of the pyramide, which is the focal point should be at the objectives plain. But then, of course there is wasted a lot of light outside of panel area!
Looking at the 2. pyramide going up from LCD to objective:This 2. pyramide isn't supported by the light path! If it was, the light rays would match with these of the 1. pyramide!
So you have no other choice than:
a) take a fresnel, which has the focal point at objective lens and blockout the unused light with a blind at the fresnel' state
b) try an objective with shorter FL
c) prolonge the fresnels FL with a second fresnel with negative FL
For a better light efficiency the reflector could be smaller, so that the overall aperture decreases in size. Condensors don't need to be larger than the LCD.
If you have OHP setup, then the parabolic reflector completely changes the light path. In common OHPs the point lightsource allows the apex of the light pyramide to be shifted towards the objective. Using parallel rays from a parabolic reflector, there's only one place where the apex can be, and thats the focal point of the fresnel. But this point isn't the objective of the OHP!
Hope you understand my rough explanations!
xblocker |
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| icculus |
| i know this is off topic, but i'd like to know what software you guys use to make your diagrams. i've had a few ideas, but don't have the patience to use any of the 'draw' type programs i have, and don't have a scanner(no space on my desk). i'd like to be able to make a reasonably accurate rendering without spending more than 20 min. |
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| chukie1 |
hi all first off i want to say i have been reading this forum for a few weeks now and i am truly impressed with the ideas that have come about, and i had a question has anyone tried to use fiber optics to concentrate the light source into the lcd panel , if done correctly i think this would do two things, one remove the heat issue from the lcd and lenses , and two you would have little light loss and most if not all the light concentrated on the lcd panel , please let me know your thoughts on this idea, sort of a socket around the lamp housing with the fiber optics connected to the front then another housing attached to the lcd panel with the fiber optics running into that. what do you think.
thanks chuck1 |
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| remp |
Greetings Chukie1
I see you are a new guy. Welcome to the board.
What you are saying here sounds pretty interesting. Could you do a diagram of what you have in mind.
Thanx |
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| chukie1 |
| hi guiys here is what i had in mind if you connect the fiber optics to a sort of lense cover at both the light source end and the lcd panel end you use the maximum light without losing any around the edges, also depending on how long a run of fiber optics you move the light source away from the lens and lcd making them less likely to heat up i think what do you think |
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| chukie1 |
| quote: | Originally posted by chukie1
hi guiys here is what i had in mind if you connect the fiber optics to a sort of lense cover at both the light source end and the lcd panel end you use the maximum light without losing any around the edges, also depending on how long a run of fiber optics you move the light source away from the lens and lcd making them less likely to heat up i think what do you think |
the only problems i can see for this after contemplating it all night is the following.
1. using the cool fluxen or ??? name for the 65w fluorecent worklight idea it still has some heat i am afraid so i think you would need to put a small set of fans in the area of the light cap to solve that problem .
2. i would like to make a same size rectangle about the dimensions of the light source and stack fiber optic strands to fill it so you get the maximum light, this could be a problem at the lcd panel end because of the amount of fibers it would take for a given lcd panel sze , but it would i believe give a perfectly even throw of light with little light lost because you have all the light channeled threw the fibers.
3.third problerm??? the fresnel can it be done to set the light source , lcd panel then the fresnel and then lens i guess you could run the fibers to the fresnel first and attach the fresnel to the lcd panel .
well this fiber optic is just part of my ideas for a projector i am starting, began this project after a not to great 100' projection tv project i have been working on , i found the plans online for free so it only cost me for materials, it is a neat experiment but i hate the problem of not being able to get the image clear enough for me so i am starting this project . i have purchased a sharp Qa-1000 panel 640x480 will this work to get things rolling 89.99 shipped with all cables power and case please let me know
thanks
chuckie1 |
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| ap0the0sis |
aren't fiber optics expensive? expecially since you need so much of it?
you're planning on using a 65w fluorecent worklight as your light source? i dont think that will give you the light you need to project an image onto a wall that is 10-15 feet away. some people here are using 400W MH lamp and they claim the pic is still a bit dim so i dont see how a 65 watt worklight will work for this.
my .02 cents
ap0the0sis |
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| remp |
Icculus
Windows paint is not too bad for a quickie. Its got circles, rectangles. lines. text, selection of colours, rub out, go back, fill.
You can get one done in 10 min if you are quick. The default paint window is a pretty good size for here so you dont have to mess around resizing.
First time you save, select "save as" from file menu and before you save set the file type box to .jpg |
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| erasmo |
hi
maybe someone knows where could i buy a Sharp lcd panel in germany ?
maybe some shop in berlin ? conrad ?
google gives me nothing :-(
thanks
erasmo |
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| chukie1 |
yep the expence is one of the problems all right
as for the light this is a flourecent flood light 65w 6000 lums
i may need two but should give me enough light this is the cool light lighting of america sells equal so they say top about 600w haligen |
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| chukie1 |
| ohh ya i can not even look at this light when on very very bright and projects the light well to the screen. very coooool |
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| Mario007 |
| chukie1 flourscent lights are not point sources which means it will not look good. As not enough light will reach the panel. How are you going to get a fiber all over that? Sure it may look bright now but people are complaning that 49,000 lumen metal halides aren't cutting it. |
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| chukie1 |
| well just doing a simple stand the light in a box put a fresnel in front and focus lens in front of lcd i have a decent pic so even if i must go to two bulbs at 12,000 lums and these are wall mounted with case flood lights i think it will work okay .ya the fiber optic idea does have it's draw back as in amount of fibers needed that is one of mt reasons maybe not to use it not sure yet. |
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| jvisaria |
the point sourceness of it all isnt really that big a deal in his idea because the fiberoptics parallel-ize (word?) the light for him...
Fiberoptics can get expensive... however... what about small glass rods? They can be found pretty cheap every now and again..and a stack of them might do the trick?
Anyone have any input? |
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| xblocker |
jvisaria,
fiber-optics don't parallelize incoming light.
1. Light is coupled into the fiber within a certain angle of acceptance(probably wrong translation?) and is coming out as a light cone. No parallel light here! Exeption: laser light in a monomode fiber!
2. If you have no parallel light coming out you have the same problems as already discussed with multiple LED light. Each ending of the fiber should have it's own condensor and must additionally point to the objective. (lens array)
xblocker |
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| thumper |
NEWBIE ALERT!!!!!!!
I have read EVERY SINGLE post in both the old and existing threads for the DIY projectors. I gotta tell you, you guys are too much! It's like following a soap opera every day, waiting to find out what's next. It's been great!
I have finally embarked on my DIY projector and am using the following design:
Light Source - Condenser Lense - Fresnel - 5" LCD - Fresnel
Light source is 250Watt MH with no reflector, light tube or cone. Just a big old bulb burning my eyesockets out while I'm working... Condenser is from inside of Delta IV CRT projector lense (it's the middle lense when you disassemble the lense assembly), two fresnels (page magnafiers from staples) and the 5" LCD is from Parts Express.
It is set up in prototype right now (that means I have a disaster waiting to happen on my project desk:o )and I gotta tell you, I'm getting one heck of a picture???
I'm projecting about 12 feet onto the wall, the room is FULL of ambient light from the MH bulb, and I'm not using an objective lense, simply the second fresnel after the LCD and focusing with it.
This does not seem like it should work at all. I have tried to use the objective lense (again, from the Delta IV) but it is a real pain to focus (and not the ouside edge stuff that was talked about earlier, that was fixed by taking out the first SUPER planoconcave lense that is at the begining of the lense barrel). The focusing problem is from the two fresenels overlapping pictures onto each other and then trying to converge them with the objective. That's why I just started using the fresnels. Has anyone else had any experiences with this?
P.S. when you put the condenser lense RIGHT NEXT TO the light bulb - make sure it doesn't touch!!! I'll be heading out to get another Delta IV to scavenge the condenser out of tomorrow. The bulb BOILED surface and now I have a big spot with a bunch of little bubbles. (yes, it's glass and not plastic...) Teach me not to pay attention
:confused: |
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| thumper |
| This is how simple the design I'm trying out is. I have no idea how it's going to work once I get the housing built and actually add a brushed aluminum reflector behind the bulb. |
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| uvodee |
i used 2 Fluorex bulbs 65 watts each and 6285 Lumen
so about 11.000 Lumen if you deduct the 10 pct efficiency loss.
i have some pics for those who might be interested
by the way, ZARK rules and those who do ot believe it, i will let you see my project copied from the Master himself! |
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| uvodee |
some info
i will reduce the size of my pics to under 100000 bytes, as larger ones are not possible to post ..... |
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| Gunawan W |
Hi Daveb,
when you use parabolic reflector, it suppose to produce parallel light and it should have a size slightly bigger than LCD panel.
Xblocker is right, see my rough sketch below.
Hi Multiplexor,
please try printable version of this thread (part 1 & 2) and search for chromatic and spherical abberation, you will find lot of this topic then.
Hi chukie1,
please try printable version of this thread (part 1 & 2) and search for fluorecent light or LOA, you will find lot of this topic before you start your shoping...
Good luck. |
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| daveb |
Gunawan,
I see what you're saying (and drawing). And maybe it's time I change my optics. Here's my dilemma:
The optics I'm using come from an overhead projector, and the native distance from the surface (where your transperency would go) to the lens assembly is 12.5". So far as I know, to get a focused image (projecting 12' across the room) using this lens then the object being projected MUST be at this distance from the lens.
Meanwhile, the fresnel which came with the projector has a native focal length of about 5.5" (the distance at which you can burn a hole in the picnic table by shining sunlight through it)
If these two things are true, then I propose it's impossible to place the objecive lens within the focal length of the fresnel.
PLEASE tell me I'm wrong, and this can work. Otherwise, it's time for new lenses all around, I think.
dave.:( |
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| woneill |
daveb,
Your situation may not be as dire as it sounds...
If your fresnel is from an OHP, then the trick to remember is that it is (probably) really TWO fresnels, each with a focal length of around 12" arranged so that the first one collimates diverging light from a point source into a parallel beam, and the second one condenses that parallel beam into a cone.
When you focussed parallel rays from the sun, you will have been treating the combined fresnels as a single lens with a focal length roughly half of the focal length of each fresnel.
If this is the case, then, with a parabolic reflector producing parallel light, you will not need the first half of fresnel doublet, because its work is already being done by the reflector.
In that case, you would be left with a single fresnel with a focal length compatible with your primary objective...
Bill. |
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| daveb |
Bill,
An interesting approach. However, I do believe that my fresnel is a single, not a double. I've taken it out, and it's got one side smooth (the side towards the bulb) and one ridged (toward the lens).
Perhaps the right thing to do is to replace it with a different Fresnel. Any idea of the typical focal length of the "page magnifier" available at Stapes et al?
The one from the ohp is plastic, so I don't think I'll feel like I'm wasting it if I don't use it.
dave. |
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| icculus |
| the focal length of the 2x staples magnifier i got from staples seems to be ~14" |
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| woneill |
Hi Guys,
If the focal length is 14" then all is well.
I have never tested mine, and my memory is not good tonight, but I seem to remember that generally for a lens, their magnifying power is equal to the number of times their focal length will divide into 25cm (about 10").
It is something to do with near point of the eye and the amount by which the magnifying glass pushes the virtual image away from the viewer...
If I am right, then with a 2x lens, you will see a 5" (12.5 cm) focal length.
Here's a link I found that might help clarify my ramblings...
http://acept.la.asu.edu/PiN/rdg/elmicr/optical.shtml
Bill. |
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| woneill |
Gustavo,
Many moons ago I mentioned that, "the image was still dim..."
I was talking about using a normal laptop with normal brightness to demonstrate how a large LCD panel could be used with a fresnel to project an image.
The dimness was because the light output of my laptop is not very high, and while it is ok to use, it is not good for projecting with... ;)
If I put a high power light source behind the screen, the image would be much brighter when projected on the wall, but without shades, it would be unusable as a laptop. :cool:
Bill. |
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| uvodee |
I do not understand why this forum cannot see success when there is
i posted some pics yesterday from my projector, homemade, and working perfectly, thank you. and no one replied .... ???
Is this perhaps a) because i used the FLUOREX 65 watters ? i noticed that some people are completely ignoring them = those i invite to come and see The hunt for Red October and i will record their reactions........
b) is it perhaps because success is not an option ????
c) perhaps someone on this forum is trying to invent hot water???
---- I watch movies now on a 95 by 48 screen (yes plas tek poly white) with a MINTEK dvd player that costed me $69.00 at Best Buy (new , not refurbished === people that buy dvd plaers on ebay should have to see this one! plays about every format there is including karaoke, dvd's that i copied with dvd copy plus = VCD format etc etc..
I have 16/9 format & wide screen at home for less than a regular tv. My whole project without the dvd player costed me (including the wooden toy box (from IKEA for $9.95) US$160.00
I will be posting pics on a regular basis, including pics during projection, as long as the moderator does not kick me out of here .
I enjoy it very very much!
now for me, and i suggest all of you, your next project or for most of you you the first one( i suspect) will be a lcd projector with a lcd monitor screen of 2.5" or smaller , so that the whole casing can be a bit more compact... i admit that 25"*16"*11" is a bit big.
This should really become the talk of the town as.....
a projector with a 5.6" and FLUOREX floodlight is already working boys! |
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| uvodee |
by the way, there is a serious flaw on gunawan's excell sheet with one and 2 lenses. Something that is truly impossible ...
i wonder if anyone else has noticed this... |
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| Assailant |
| quote: | Originally posted by uvodee
i posted some pics yesterday from my projector, homemade, and working perfectly, thank you. and no one replied .... ???
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do you have any pics of the actual image produced? i mean it's all well and good to post pics of the enclose, but what are we going to say/comment? nice IEC plug and switch? |
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| multiplexor |
| quote: | Originally posted by uvodee
I do not understand why this forum cannot see success when there is
i posted some pics yesterday from my projector, homemade, and working perfectly, thank you. and no one replied .... ???
Is this perhaps a) because i used the FLUOREX 65 watters ? i noticed that some people are completely ignoring them = those i invite to come and see The hunt for Red October and i will record their reactions........
b) is it perhaps because success is not an option ????
c) perhaps someone on this forum is trying to invent hot water???
---- I watch movies now on a 95 by 48 screen (yes plas tek poly white) with a MINTEK dvd player that costed me $69.00 at Best Buy (new , not refurbished === people that buy dvd plaers on ebay should have to see this one! plays about every format there is including karaoke, dvd's that i copied with dvd copy plus = VCD format etc etc..
I have 16/9 format & wide screen at home for less than a regular tv. My whole project without the dvd player costed me (including the wooden toy box (from IKEA for $9.95) US$160.00
I will be posting pics on a regular basis, including pics during projection, as long as the moderator does not kick me out of here .
I enjoy it very very much!
now for me, and i suggest all of you, your next project or for most of you you the first one( i suspect) will be a lcd projector with a lcd monitor screen of 2.5" or smaller , so that the whole casing can be a bit more compact... i admit that 25"*16"*11" is a bit big.
This should really become the talk of the town as.....
a projector with a 5.6" and FLUOREX floodlight is already working boys! |
Oh, I saw your pics :D
But people will really comment when they see a final result. Show the people some displayed images :)
I do like the switch you used. looks tough and will last long ;) |
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| thumper |
I would absolutely like to see more on uvodee's projector. But what was posted was just not enough to get a good idea of it's total construction and results.
Uvodee, how about some pic's of the whole box so we can see how you finally put it all together. The box construction, the light - lense configurations, etc... You know, wide angle shots of the whole shabang.
I'd really like to see how people are mounting their Disassembled LCD's ( for those of us that are using the small disassembled monitors ) as I am having trouble getting a tight enough fit around it to prevent light through the edges of the mounting. Did you expoxy it to a piece of glass or construct a frame so there was no additonal light interference? Being too forceful and breaking it is not an option. Although $120 is a pretty good price, they're too expensive to replace all the time.
I for one don't care if two wax candles can be made to work well enough to generate a good quality image! What I posted earlier is working pretty well, though hopefully I didn't give anyone the impression that I had duplicated a $5,000 commercial projector:rolleyes: . I just think that for a very first time attempt that it puts out a good picture with no screen door or moir (is that spelled right?).
I'd still like to hear from anyone who is using or has tried using a condenser lense and two fresnels without a final objective lense. From what I can see, it's going to work out real well. It's just a matter of mounting it all in a frame and keeping the plastic fresnels perfectly flat. |
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| erasmo |
hi!
so nobody knows where could i purchase a lcd panel in germany ?
preferible Sharp @ 800x600, active, polychromatic
any ideas ?
thanks |
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| Redevil |
uvodee
Way to go
So now we have options.
I would be interested in seeing your setup.
Man that would be great to go from 400watts to 130watts
and a lot less heat.
Keep us posted
My settup is also working great.
But will be willing to save money on energy bill.
Also to measure our light output to the LCD we should set a standard.
Example: Find a standard solar cell, say from Radio Shack.
Something that we can all get. Then attach a volt meter to it.
Put the cell in the centre of the LCD and 4 corners on the light side and measure the voltage.
The person with the same 5 voltage readings and the highest
would be the winner
Later |
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| Mario007 |
| Redevil hmmm It would be cool if we could simply measure it that way but there are some problems. For one distance from the lcd is a issue,not all cells are the same in their light picking up,multimeter that would test the light cell would be different,we would have to have the same image going into the panel,ambient light picked up. See although it would be cool if there was an easy way to measure brightness there isn't. |
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| xpndsprt |
I've been hearing alot of ppl say that their panels arive either defective or not copatible with their videocards .. in both cases i'm talking about vsync problem (screen jumps)
here are POWERSTRIP settings that corrected that little nasty on my panel :) |
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| uvodee |
[QUOTE]Originally posted by Redevil
[B]uvodee
Way to go
So now we have options.
I would be interested in seeing your setup.
Man that would be great to go from 400watts to 130watts
and a lot less heat.
Keep us posted
Because YOU asked for it, the enclosed box before cutting the frame for the screen/lens |
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| uvodee |
i hope you have an idea how the plastic was cut in order for the casing to be put in the box.
Anyway this was how they got inside..... |
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| uvodee |
this form another angle ....
gee this makes me tired !!! |
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| uvodee |
I really question ( and more often than you think) the honesty of R&D depts when it comes to the purpose of launching completely useless, inefficient products, hence some of them based on conclusions that were given in by sales and not by knowledgeable beings. Let me explain
1+2=3. 3+2=5,5+3=8,8+5=13, 13+8=21,21+13=34,34+21=55.
correct ? i think so, now when you divide the result with the first factor the figure you get is always (ALWAYS) 1.61
example 55/34 or 34/21 both result in 1.61
this is called the Gulden Snede or Golden Cut i think in English
(poor Fibonacci struggled more than 1.61 years to understand why.....
The gulden snede was ( and is still used by painters (visual artists) in order to create a PERFECT picture for the viewer.
How was this done?
well let's say a portrait: every inch horizontally should have 1.61 inc vertically so a portrait of 20 inches wide, MUST be 32.2" heigh
For a Landscape the opposite is through
55 inches wide gives 34.16" heigh.
Ask you eye doctor why this 1 on 1.61 is so perfect.
and Could any one answer me this... why are those darn Matsushita r&d people studying the golden cut for a possible new type of screen ( likely to be within 2 years on the market!!!!!!!!!) |
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| uvodee |
I thought my screen was going to break if i just screwed it against some mounting frame, so i used a black foam i bought at Lowe's to place it between the screen and the wood frame....
i kept the plastic frame from the LCD so it was a piece of cake to use tiny screws for mounting it. I am going to look for the pics of that and will post them, i hope tomorrow! |
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| daveb |
After hours of re-jigging the light and optics, I went to try out the panel in the light path, and with a small puff of white smoke, my panel is dead.
:redhot:
I've been working on this since beast since april, and I'm at wit's end.
I now have a very nice 400 W MH ballast/socket/lamp with only about 1 hour of use that's ready for a new home. I've also got two fresnels and the objective lens head from an OHP that I won't be needing...
Turns out the optimal focus for the reflector was much lower than I had been using, so I cut out the bottom portion to situate the filiment at the focus, and lo and behold, a ton of light now screams out the top.
Too bad there's nothing to shine it at.
dave. |
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| Spanky_Mcfarlin |
| If your done with your bulb will you consider selling it to anothe DIYer? Let me know.... |
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| Gunawan W |
Hi Daveb,
you're right, if you use parabolic reflector at it's focus point, but there is another way, see my sketch below, if you can put your lamp at a distance shorter than reflector fl. you will get spreading light beam.
Put the lamp & the reflector at fl. of fresnel panel, then you get parallel light output.
Moving the lamp unit backward (> fl. of fresnel) the light beam start to condense! Keep moving it until the light beam just fit your objective lens.
Good luck.
Hi uvodee,
Please tell me what is wrong in my excel sheet, so maybe I can fix it if have enough knowledge, thank you. |
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| daveb |
Gunawan,
yes, that would work too. But I'm now panel-less. Without one, I've just got a nice big white rectangle on the projection screen.
Great for making shadow animals, but not much else... |
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| woneill |
Hi Daveb,
Sad to hear about your problems. How did your panel die?
Is there a lesson we should all learn here?
Was the puff of smoke an electrical thing, or was the output of your lamp focussed to a point on the panel?
Bill. |
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| gkase |
Hello all,
I too have read with interest what's going on...
can someone point me to a location where someone has identified a likely (and relatively easy...read "no micro soldering") lcd panel that they have implemented? I want to go the non-projection panel route. As a side note, about ten years ago I built a crt based projection unit using the Delta lenses and three little 4" crt TVs...I have been stewing about the LCD idea for some time and have been knocked out by the last weeks reading of the video threads...great stuff!
George |
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| thumper |
Uvodee,
Thanks for the mounting tip. I too, fortunately, kept the frame intact for future use. Your rig looks great! It's given me a few ideas for my case design.
gkase,
I don't know if your referring to a vga monitor or a tv (composite video in only) monitor. I chose the 5" tv monitor sold at parts express that is typcially used in vehicle installations. The resolution isn't superb, however the price and simplicity of use and installation is. I personally don't have any use for "computer on the wall" so I didn't need that option, my kid uses video game consoles and dvd/vcr only. I intend to use it for tv and dvd/vcr only. We'll see who gets more time on it, me or my kid!:D
for all,
I have modified the optical design I previously posted to this:
light - condenser lense - objective lense - fresnel - fresnel - LCD - fresnel
The condenser lense and objective lense are "butt" up against each other right after the light source. This has greatly increased my brightness. I am in the process of using the previously mentioned "mixing bowl" to work up a reflector. I feel good about it after testing it with lower intensity bulbs. Now I have to cut the hole for the monster MH.
as is, the only screen door effect is on bright white areas or if you walk right up to the wall. and then it only lasts a few seconds as your eyes automatically adjust to it. I think it's as good as I can do with the montitor I'm using.
By the way, as I mentioned before, the condenser and objective came right out of a Delta IV CRT lense at a cost of $4 from a surplus electronics place downtown, so don't write off the Delta IV because of the fish eye problem that was pointed out many moons ago. Just take out the first concave lense and the other lenses are absolutely normal (and big enough to keep you unit from being twelve feet long! Mine looks like it will be about 30" long...)
Keep up the great work, we're getting there..... |
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| gkase |
Thanks for the tip on the 5" monitor...are the electronics easy to move out of the way?
Are your fresnels from office supply (8.5x11 page size)?
Thanx
George |
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| BenY |
Hi there,
I don`t understand this...
Why would anyone want to build a home made projector using fresnel lens and going through all this,When you can get a used High quality LCD or CRT projector on Ebay for a song. |
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| thumper |
George,
Yes, the electronics were fairly simple to relocate. I simply unscrewed the boards from the back of the backlight and folded them up and screwed them (using the same mounting holes) flat against the board I mounted the screen on (Kind of made my own frame out of 1/4" sheeting. Kind of like opening a book and screwing it's covers down to the table. The backlight then slid right out of the frame. The parts express part # is 205-013 and the power supply that I'm using is #120-532 (it's a pyramid regulated power supply that I'll also use to power my 12v fan).
The fresnels are plastic 81/2" X 11" from Staples. I got a picture good enough to sit and watch Star Ship Troopers last night ( I still can't believe that's my favorite movie. My wife laughs everytime I watch it...). I'm going to keep my eyes open for glass fresnels to increase the focus and brightness even more though. I imagine glass fresnels with very fine grooving will be quite an improvement, but rather than buying them I'll wait till I can salvage them somehow and from somewhere. For now the plastics work fine.
Still waiting to cut open the "mixing bowl" to create the reflector. The shape, size and finish look perfect. I got it at "Big Lots", a close-out type store here in Florida. I was "Dad" tonight and had to hang up my "Mad Scientist lab coat" so I didn't get to it yet. Maybe this weekend, the kids should come first.
BenY,
My father used to tell me, "no one takes time to appreciate their own work any more, therefore there's no pride in their work. It's just something they had to do..." I take pride in what I build, it gives me a sense of satisfaction and continues to build my confidence and self-esteem. I try to pass this on to my kid, considering the world we live in I figure she can use all the help she can get.
Enough of that already, It's also a whole lot of fun!
I will ad some pics ASAP. I have it set up on the project table so you should be able to get a good idea of the optical sequence and how I'll have to put it all to together. I've got some pretty good ideas for focusing and what not. My brother is a skilled cabinet maker so I'll definitely be calling in on him for some help. It helps to "know people".;)
Talk at ya; |
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| gaff |
beny,
yes you could probobly find a used projector for a decent price, but i bet most people don't want to spend $400 on a replacement light every 2000 hours. many of the metal halide bulbs that we use can last up to 20000 hours and cost $40.
gaff |
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| multiplexor |
the main reasons why i jumped in on this is because it's simply cool! For a low price you can build yourself a pretty good quality lcd projector.
I haven't been able to purchase more parts than the lcd panel (car problems and stuff) but when i have the cash i can't wait to get back on the bandwagon.
it's the whole "I built it myself" thing... it would feel great to build my own projector, would be cool, would be creative, would last longer, etc... :D
anywho, i gotta finish my windows reinstall... :( |
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| uvodee |
well gkase
i wasn't that lucky with my lcd compared to all the others here in this forum.
my screen had 3 flex cables north, south and east of it so only one was kept intact, the others i had to prolong ( i hope this is proper english) with extra flex cable .. Boy boy, was this a night mare or what there were 2 cable formats
one had 10 connections and was 11.15 mm (0.5 mm conn)
the other had 20 connections and was 16 mm (0.8 mm conn)
rookie that i am in the US in took me a day before i had located the supplier/distributor and allthoug digikey sent me the connectors and one of the cables, fujicard did it because i guess thesalesperson took a few moments of his break to help me... when i told him i only needed one cable from him he almost broke his neck from laughing i think! he's more used to dealing with 100.000 pieces i guess!
I will post some pics of this lcd positionning i did tomorrow i hope.
no reply on Fibonacci ??? interesting!
Jean-Pierre |
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| jamie |
i have bulit this projector even better than the plans and its like this it seems to project well when your hand are a picture is under it but withe lcd it just dont cut it ,,,with the lcd it playstation screen it looks better withe the light off useing the light from the lcd all in all so far you will get a head ake rfrom trying to see the picture its there but its just not there hope this helps im trying some new things ill post in awhile
......jamie |
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| CAD |
@uvodee
What kind of lamp is it - and where can i buy it?
greetz
CAD |
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| mycamel |
| quote: | Originally posted by BenY
Hi there,
I don`t understand this...
Why would anyone want to build a home made projector using fresnel lens and going through all this,When you can get a used High quality LCD or CRT projector on Ebay for a song. |
For some of us, its a reason to learn something. I've already learned more about optics than ever before. Several years of doing my own B&W film processing didn't force me to really understand what was going on inside the boxes I used, but this does.
Remember Heathkit? DIY is cool! |
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| Billett |
Hey what's that big ball of wires behind your lamp housings?
I have been experimenting with one 65watter and i barely get anything but a dim image. Worse than what i have with my 1953 300w projector bulb. Will adding a second really make a big enough difference? Did you refract or reflect the light in any way. Did you use Frenzels in front or a or Mirror behind?
Thanks for the inspirational pics.
Now i need more! More ! MORE !
Paul |
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| Billett |
| quote: | Originally posted by thumper
This is how simple the design I'm trying out is. I have no idea how it's going to work once I get the housing built and actually add a brushed aluminum reflector behind the bulb. |
I have had success using a fresnel as a projection (after LCD) lens. The clarity was much better than i expected and there was no noticeable distortion like i had with my glass fish eyes. Now I'm trying to find a way to increase my light output. Maybe then i will notice problems but for now the cheap staples lens is working very well.
Paul - The Nephilum |
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| Billett |
| quote: | Originally posted by CAD
@uvodee
What kind of lamp is it - and where can i buy it?
greetz
CAD |
Hey G!
Not to step on unvodee's toes but i can tell you what light he's using. I've spent a little time trying with one lamp but that wasn't bright enough. His system has two.
It is a FluoreX bulb sold by Lights of America as a Fluorescent Work Light. Its 65w and they claim its output equals a 500w halogen. It IS bright and i can't argue that it wouldn't make a great work light.
It is relatively cool (acually cold compared to some of the projection lamps i've tried). It is so white that it makes my walls look yellow but it does not project a beam. I'm finding it hard to focus all the light onto the frensel & OHP Panel. It seems uvodee has found a way to make it work.
I got mine at Wal-Mart and I've read that they are also available at home depot and other DIY home improvement places.
For more info search our forums for Fluorex.
Mine was $24.95 USD
Hope that helps!
Paul - The Nephilum |
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| biteon |
ive notice there are two ways that light should travel from the light source setup for even light. parallel rays from the bulb and reflector, or ray evenly spread from the point of source(yes the ray can be reflected as long as they reflect back in the same direction they came from "the point of source") but the thing is we cant go with both because they use different lens setups. i might be wrong but i doubt it. see the pic's below
i just thought about it and im wrong on one part .with a parabolic reflector its not posible to get even spread parallel rays.so basicly
lasers dose parallel even rays, and parabolic reflectors do both parallel and raysfrom point of source, and 1/2 sphears reflector setup dose evenly spread light from point of source. ill put some picture exsamples in a little bit to explain the two way that would work and the resond why parabolic might not be good for even rays of light. i still might be wrong on this so tell me if im wrong. |
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| biteon |
| i think parabolic sucks for projection and thats all i got to say about that. forrest gump yes. |
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| thumper |
| This is an overall picture of the optical sequence. |
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| thumper |
| condenser/objective setup |
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| thumper |
| The LCD mounting (temporary but you get the message). The boards simply folded up (see the triple ribbon cable a the top of the screen connecting the screen and the green board). The three boards have holes in them to run small screws through and secure it to the mounting board. |
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| thumper |
I TOTALLY agree with everyone so far who has said "digital cameras were NOT meant for dark or low light conditions!!!!!!!!
This is the best I could get. I wouldn't want to tell my family they had to watch it as a primary right now, but I have watched it two nights in a row with no discomfort. The dark area at the top right is a piece of paper I was using to try and block some of the ambient light. The white at the edge of the picture is the poor temporary framing job I did around the LCD panel.
I really feel that the reflector will help with the brightness. Even if it doesn't though, I've at least proven how to do this type of setup, and just replace where I have a 250watt with a 400watt. I just don't feel inclined to go out and spend another $70 or so for a new ballast and bulb until I've exhausted all other means.
The other types of setups have their own way of doing it and who knows, may very well look a whole lot better.... The whole issue boils down to "how much you wanna pay?" High cost, high quality parts will produce a higher quality picture. I think that with ongoing tinkering someone will find just the right combination of locally available parts to make it all work just right.
I don't think this is too bad for a bunch of stuff propped up with coat hangers and cardboard. I will begin on the permanent housing as soon as I'm happy with some kind of results from a reflector. |
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| uvodee |
2 floodlights ????? 65 watts each fluorex bulbs ( bulbs alone cost about $9 each and go about 25.000 hours)
i did not remove the photocells, hust covered them with some black tape (yes i was too lazy!)
then i used ONE of the orignal covers to hold them together in the front ( i reversed a frontplate and used some stainless steel nuts and bolts (see detail of one of the pics)
the rearend was put together with again nut & bolt
the reason for using one orignal cover is: the plastic is perfectly heat or should i say warm resistant= no significant increase in temp. I incorporated a 5" 12 Enermax fan, i should have known better: more cooling that it needs but that's ok for now.
I piad $30 each at Home depot
the plastic fresnel ( i want to change it to a glass one) does the focussing or should i say in my words the job pretty well : i coudl clearly see the light being brough together into a rectangular shape and then i covered the fresnel with black fotopaper that i recuperated from a foto book ,and i cut out the size of the lcd screen.
i saw this at ZARK's website and s. o. a. gun that's all it took
soe playing around with 2 lenses delta IV and delta 67
( both have there good and bad points!! and
this weekend i have some friends over for the ocean's eleven viewing! with beer from my homecountry Belgium: Stella, Geuze, Hoegaarden en Triple Palm!
Skoll! |
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| CAD |
Hi Billett, hi uvodee!
Thx for the Infos!
Which online-shops sell this lamps?
You must know i came from Autria... (not Austriala ;) )
So a shop in UK, Germany or Austria would be good.
thanks,
CAD |
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| access256 |
OK I am finally ready for my first post. I've been reading both parts of this forum (wow like 230 pages) I tried to print the first part and it was going to take over 1000 pages! Any way I have been playing with the flourex lights and heres what I got so far. I tried 1 light and got a washed out image but a viewable one in darkness. Then I was hesitant but went out to get another and tried that. The strangest thing happened when I put 2 of them behind my lcd the contrast of the lcd looked sooooo much better. Then I put my lens on front and almost passed out!! The image was beautiful. Now this image is through the lens of one of those Chrstmas/Holiday projectors that you put in the yard (my new lens should be here anyday.) Now I still don't have any frensels with the 2 light set up yet (got too late) but hopefully tonight I will get a chance. My question is how does this setup behave with light in the room. I have only tested at night (pitch black) I tried to get an image on an overcast day but was unsuccesful but my lens is only like 1.75 inches. Also I purchased a Delts 67 lens and it is just useless (the typical focus problem due to curvature). Anyway sorry for the long post just wanted a little input and let you know my progress. Maybe I'll try to take a pic of the image tonight and post it.
p.s.-- I also have a 400 watt MH fixture and buld at my father-in-laws house for free just incase :) |
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| gkase |
Hi,
I am interested in making a "from scratch" lcd projector ala thumpers design and others...here's an observation that may be of use. I went ahead and purchased one of the overhead projection panels that is ready to go (it's an Apollo Q2 unit)...of course I tried it out on the overhead projector at work and it worked great. Here's the observation: The distance from the fresnel/glass stage of the overhead to the actual LCD unit is about 1"...in other words, the LCD and the fresnel have some distance between them and are not butted up against each other. Thought that was interesting.
George |
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| jco9w |
Hey all,
Been a while since I posted because I defended my Ph.D. successfully and started a full time job. I finally got my condenser lens from Surplus Shed, but it isn't matching up with my current Fresnel and objective optics well. I am just going to buy an OHP and strip it out to build the optics of this thing.
uvodee- I would be interested in LOA's but I want to see some screenshots of your projector working, not just the box. To me it seems like you must be getting hotspots and coldspots, because the setup you have can't be creating a nice even light field. However everyone has different standards, so I respect that you have something you like. Please post some screenshot when you can!
J |
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| uvodee |
so you live in Austria...
humm Gaby Addler from some place in south Vienna city, thang long time ago .......
well any way , Gaby left such a strong impression on me that i now like all austrians!and if you do not find them in Austria, i can send some over there.
will not be very cheap i guess and then there is the issue that the ballasts/bulbs are 120 and not 220 volts. the packing is not that heavy .....
if you want to i could do it for you. you can pay me through paypal i guess, i have an account there for my ebay and other bizz. i bought them at Home depot at 29.95 each plus 8.8 pct sales tax (local sales tax)
let me know if you are interested! |
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| uvodee |
I would sincerely like to know what you guys think about the issue of NOT using the 16/9 out of respect of the humon body and old masters of paint!
What do you think and if you hesitate, look at a 16/9 and 16.1/10 format before and then answer ........
Jean-Pierre |
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| Gunawan W |
Hi Biteon,
I think nothing wrong with parabolic reflector, good parabolic reflector will produce even parallel rays, of course there are some direct rays intervene parallel rays, from your previous attch. dwg #4, you describe clearly that direct rays mess up with parallel rays from reflector, that's why I propose to put small lens in front of the lamp to convert direct rays into parallel rays too. (see your previous attch. dwg #2).
From your attch. dwg #1 & 3, it's standard configuration of OHP, except OHP has second fresnel to condense parallel rays into objective lens.
Parallel rays is the best way to pass thru the LCD panel to avoid hotspot. |
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| daletmp |
Hi All
Is it possible convert a laptop lcd panel to receive PAL video signal ? I am planning to buy a laptop lcd panel (IBM THINKPAD 760 C/EL 12.1" ACTIVE LCD PANEL) from ebay. Is this model good ?
Apart from lcd panel what else I need , how much it will cost. |
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| uvodee |
Dear Cad, the pc psu is being used for a) the fan, b) the lcd monitor .
the lights are 120 volts ac and come after a fuse i put in just to be sure.
I personnaly think that fluorex technology is in Europe much longer than in the US maybe not under this name, have you tried Sylvania Europe ?
Jean-Pierre |
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| uvodee |
| pic of the $9.95 toy box while under power |
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| uvodee |
a pic of the opening while lights are on before i installed the lcd , gresnel, glass and lens
Oops almost forgot, I used smoked glass in front of the camera, just to be sure that the optics inside the camera would not get damaged.
Me, i had no idea i had to do this, it was an engineer(my wife) who told me so!!!! grmmmpppsfffffffffffff!!!!
Jean-Pierre |
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| uvodee |
Looking at the last posted picture i almost got blinded.
be carefull not to stare too long to the pic ok !!
Jean-Pierre
who said on this forum i wasn't a sensitive guy! |
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| ainsane |
Hey, I'm going back to school so I dont have time to finish off my projector :(
I'm selling my 400W metal halide bulb, ballast and socket. I only tried them out for 10 mintes and it works great.
check out my ebay auction if interested.
http://cgi.ebay.ca/ws/eBayISAPI.dll...2049622350&rd=1 |
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| CAD |
| quote: | Originally posted by uvodee
Dear Cad, the pc psu is being used for a) the fan, b) the lcd monitor .
the lights are 120 volts ac and come after a fuse i put in just to be sure.
I personnaly think that fluorex technology is in Europe much longer than in the US maybe not under this name, have you tried Sylvania Europe ?
Jean-Pierre |
Sylvania by OSRAM
I will inquire by osram!
Which model is your lamp?
Ist the Lamp hot?
I tried a 1000W/220V Halogen Lamp - the brightness was great - but simply too hot! :( |
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| Billett |
Jean-Pierre AKA uvodee
Well that looks bright!
Sounds like when combined 2 units put out more than twice the amount of focusable light. But is that all the light you want? I don't feel like spending an extra fifty just to find out it works but should be brighter.
The reason I'm attracted to this light is not because I'm a moth but because it would be so easy to contain. I don't want to close in the hot bulb that I am using now. I can't hold my hand 6 inches above it for very long and it's barely bright enough. If these 65 w lights do the trick they would be so much safer.
Jean where do you live maybe I'll take you up on that offer to come over so you can prove that it is bright enough!
Paul Billett - The Nephilum |
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| chukie1 |
| hey there fellow 65 watt fan i to am working on a projector usung the flurex 65 watt bukbs and i also live in washington st where abouts do you live maybe i can stop by and check out your setup. |
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| vinyljunky |
Hello everyone, it really is about time I posted, I have absorbed so much and given back so little. I am at the stage of trying to tweak my projector to get a better image from it. My current setup is:
MH400W<->(100mm)<->OHPFresnels<->(~20mm)<->Projection panel<->(~400mm)<->8-1/2" PCXlens
The screen is about 3meters from the PCX lens. Transmission of light hasn't been too much of a problem for me. All but the darkest of scenes is viewable with daytime ambient light and I put this doen to the size of my PCX lens - it really is an impressive size and weighs over a kilogram (f400mm).
The problem I do see is the symptom of the single lens objective -aberration both spherical and chromatic, at the edges of the screen. At least thats what I think it is. Would this fit in with the visible symptoms of aberration? I'm not entirely sure if aberration is a symptom more obvious on the center or outer of an image.
Another observation I make is that the smaller you make the projected image i.e. the closer you move the projector to the screen, the less apparent the blurring is. But of course, I would like to retain the bigger image :) .
Possible solution? : I believe that part of my problem may be due to my fresnels - Just two page magnifiers face to face. They have a combined focal length of 10mm and my PCX is f400m. In other persons experience, does a closer match of f(fresnel, objective) render a better image? I would of course be very interested to know of anyone else's experience in this area.
I understand that with this kind of system there are limits and you will never get the kind of performance demonstrated by commercial projectors, but I'm sure there is room for some improvement in my system.
Apologies for the long post, had to get it all out of the system ;)
J.Cousins
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Please check out my projector pictures at:
http://www.imagestation.com/member/?name=jamescousins |
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| Gunawan W |
Hi vinyljunky,
my setup very similar with you, unless I use Halogen floodlight but I'm going to change with MH too.
How is your projection image look like?
Do you get uneven sharpness of the image? ie: sharp on the middle but blurr on all of outer sides? (I think this is called spherical abb.)
have you try to cover 1/3 of lens diameter (outer side) to reduce this problem?
About your fresnel, as long it can cover your lens with light beam (with adjusting it's position towards the lamp), it's OK.
I just received more lenses from Surplusshed brought by SushimasterX, thank's Gary...
I hope I get more quality improvement with this new lenses, I'll report here soon.
See you. |
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