Hi, i need a little help here, I have a PSone lcd and I have a polaroid protable dvd and don't know which one i should use.. what do you recoment... the specs for the polaroid are the following:

7" widescreen (16:9) color LCD screen
TFT LCD Resolution: 480 x 234

I have stripped the polaroid lcd and it's quite easy... but still I'm not sure which one should I use. I know i can't get a large image but i want to do it anyway to experiment and see if it's worth the mony to make a 15" or a 17" projector in the future.

Btw, what kind of lens do you recomend? triplet or varifocal? and the FL, between what and what it should be?
thanks..

Well the PSone screen is only 320*240 so the 7" would have better resolution.

Also the 7" screen would allow you to get a bigger picture than the Psone screen while limiting the screendorr effect seen on the larger image. And you might have more adjustments with the 7" like brightness ,contrast, color ?

And I would reccomend the standard LL triplet and fresnels. They work very well with small Lcd Pj's.

thanks a lot jonjandran, yes the 7" has control over brightnes, contrast and color, also it lets me choose between wide and letter box..

also I found a cheap Kodak ektagraphic III A slide proyector and it comes with a lens that acoording to what i found is a 100 - 150 mm f/3.5 it also says that it produces 13000 lumens with a 300w EXR lamp..

will that work for my project?

how big an image do you think i can get with it?

should I keep the lamp or use something else?

I want your advise because I don't want to waste my money, thanks..

Well the slide projector's light will probably be more yellow, and probably not bright enough to make you happy.
I think the 400 watt light kit would be best.

Check once in a while on these boards and members will be selling their used light kits and lens kits for around half price. Some of them brand new because members buy them but don't get the time to install them.

ok, so I shall use a 400w kit but what about the lens? do you think that's a good one or should I get something else?

I'm not to sure about the lens. It might not be large enough to capture all the light. Someone else would have to answer that.

no problem, you helped me and that's what matters. i hope someone else has an opinion or a sugestion for the lens. thank you

Slide projector lenses come in two flavors, curved field aka CF or flat field aka FF, the difference is
extremely important.

35 mm slides are generally in cardboard mounts, and have a curve to them, the curved field lens is designed to be focused along this curve. This is a compromise because some slides dont curve, or dont curve as much so the focus isn't always perfect.

To acheive perfect focus slides can be placed in glass mounts which keep the slide perfectly flat. To go along
with this there are flat field lenses that are focused along this flat area.

The lens you have in your projector is most likely a curved field lens, if this is the case it won't provide
even focus because your LCD panel is perfectly flat like a glass mount slide. You might be thinking, hey I'll
just curve the fresnel lens to compensate, well it won't work. You see the slides curve in from the top,bottom and sides where as a fresnel lens will only flex one way.

IF you have a FF lens, then your next obstacle is finding fresnel lenses that you can use in conjunction
with the lens that is designed to focus on a 35 mm slide. Not saying it can't be used, just don't know
what fresnel lenses you could use. Now if you happen to come across some fresnel lenses, it should be
pretty easy to mock up a test jig to see what kind of image you could get.

So in summary, if you have a Flat field lens go for it, otherwise your lens most likely wont work as well
as you would like it to.


Good luck
FS