DIY Video Projector

[Undream]

also, I've got a Super Metal Halide 400w bulb on its way, which should add 6,000+lumens. Brighter is good!

[The Xung]

@Undream
You were just using a PCX? How were you not getting spherical aberrations? or were you? is that why the images seem blurry and not because of some motion blurring in the game?

My achromat finally came and I tell you it made a world of a difference. Not only that, but apparently if you throw in the right set of minicus at the right distance, it fixes the pincushioning effect. Now all that's left is to sell the 175W MH and get myself a 400W MH.

[Undream]

the photos I took were pretty bad.

1) I don't see any spherical abberation whatsoever. its clear, corner to corner. I can see individual pixels without a problem.

2) blurry images are either because of the fact that I was just holding up a lens, or, the game was moving *very* quick at the time. i could have also not held the camera steady. point is, when I wasnt using all my hands taking pictures, I could get the image next to perfect.

I cant explain it, but, I'm not arguing.

one more thing..

my pcx lens is larger than most of the ones people have on this board. its from surplusshack.

My fresnel lens converges the light down to a point approximately 18" from the LCD panel, and, whaddya know, thats the focal length of my PCX lens. it worked perfectly. Believe it or not, I think that nearly all of the light from the LCD panel is only hitting the middle of the PCX lens. That might be why I have no spherical abberation. it just worked out perfectly for me.

Also, that image is 77" diagonal. not the biggest, but, its still really, really big.

[prjctr_builder]

Originally posted by multiplexor


i called infocus directly to find out more about that 7600 model... it can't do animation buddy

so i never bid on it on ebay...
the guy said it doesn't have the circuits necessary to do it...

the only reason i want to build a projector is to play games on my computer. and i believe that the panel is made just for that!!! is it not? ......buddy....

[baybum]

I have a Sharp QA-1150 Projector Panel, but I don't have the cable to hook to my computer. It takes some kind of db-26 connector.

It works hooked directly to my VCR or DVD, and has good picture, but I think it would be even better through my computer. Does anyone know what kind of cable it might take or where to get one. Can it be made DIY?

Any help will be appreciated. Also I will post some Pics. as soon as I can get a good camera. Thanks.

[BodySuitMan]

Ive got a QA-1150 aswell and ive got the cable your talking about. All I can tell you about it is that on the end of the plug that connects to the panel it says "JST" on one side and 26p on the other side. BTW, if you think the quality was good using the composite input you will be blown away at how good a computer or other true vga source looks. Enjoy

[Fiat1]

Thanks for reply

Living in Australia can often be very anoying with cost! I got a Sharp 1500 for my set up, I am in my last year of highschool and purchased it for $150 Aust of them, if you ever look for another panel your best bet is to look in the paper and they always have auctions with these kinda things for sale from ex government kinda things. Hmm fresnel is not a good projection lens, I guess it is just an experiment. We do have a place like surplaceshed it is called Oatleyelectronics and can be found on the web at www.oatleyelectronics.com.au, they sell many kinds of things from time to time. I am gonna use my lens from my OHP possibly, I have not found a source of lens in Australia and am not keen on getting stuff from America becuase it costs an arm and a leg. Have to ring up tommorow about getting a MH globe. Where did you get your reflector? What globe are you using sorry? I am going to buy real screen material, although it will have to be from America I guess, even though I don't want to buy it from such a geat distance, but around my screen I am gonna put some blue down light to shine out around and look wiced before a movie starts!

[Fiat1]

Sorry Gav1 after reading you post I can see now you are using a 55w downlight which has its own reflector. Need a much brighter one as I am sure you already know.

[gav]

as was pointed out, my panel roughly equated to $130 american, which also includes $20 us in car parking fines and $15 transfer fee, so i think i came out alright....
fiat1, yeah, the fresnals were only to keep my confidence up i have a mate at gym who is a physics teacher who is chasing up some lenses for me, if i find a couple of possibilities i'll be more than happy to ship one over to you

i went to the ansett auction and picked up a near new projector screen for $90, works perfect for me

yeah, the light was abit dull, but with all curtains drawn and lights out it was watchable, but it definately req. more oomph...on a side note i went to my mates work and picked up his OHP for the weekend to try out, it's a 3m 920, with a 275w bulb....WOW.... just finished watching dvds on it and even my g/f was impressed (she normally just laughs at my projects ) would be nice to leave it at that but i want to do the full diy bit and make my own housing and lens assy - but it's definately insparation!!!

[Gunawan W]

Undream
I wonder with darker part on your 4 corners of the image. Looks like the perfect contrast of the image only in the middle, am I right?
You said that light beam from the panel only hit in the middle of the lens, I think because of it the problem come up.How about adjusting fresnel panel-lens distance, so the light beam hit the lens in bigger spot.Won't it eliminate dark side of the image? Or become worse than before, because it will generate spherical abb. problem.
Another possibility, does it has relation with polarizing filter in LCD panel? because light beam pass thru in slightly angle at the outer side of the panel.
What do you think?

cowanrg
Great screen shot, good contrast, clear image, I wonder what is your setup?
It will be perfect if you can take a picture behind your projector, so we can see all your setup and know how big your projected image.

The Xung
May I know what kind of achromat lens do you use (diameter, fl etc)? Do you use only one achromat lens?
How about spherical abb, is it still a problem now?
I'm waiting your screen shot, thank's.

My progress still stuck with abberation problems.

see you.