Hi all,

As some of you know I have abandoned ship and just decided to be happy with my Optoma EzPro756 DLP Projector. I would have preferred the WUXGA resolution and cheap replacement lamps but thats another story. Anyways, currently I have set up my DLP projector on the short width of my room (12') as opposed to the long length (20'). It gives me a 80" screen which I sit roughly 11' from.

Now I don't know if it's because the image is too bright, too big or if it's because of the projection being created by DLP but I find it hurts my eyes and I get a bit of a headache from watching it. Does your projector hurt your eyes at all? This is what I want to know, do any of you get headaches from your DIY Projector?

I only wach movies but never so far and my screen is about 150" from 10' away.

What is more likely occuring is the dreaded rainbow sensitivity effect. Its usually based on the color wheel speed- the higher the speed the less noticeable it is. Your pj is rated at 2x so if you're sensitive to it (and that's what it seems to be), you can try a number of things short of returning it and getting a higher speed dlp or a lcd (what users here and all commercial lcd pj owners (like me) don't have to deal with- we have other problems just as lousy)
1. try a neutral density filter to tame down the brightness- some at avs have reported that this greatly reduces RBE on their Infocus X1s
2. keep watching- as your eyes get used to the image it might also learn to ignore the RBE
3. reduce brightness- use AVIa or similar to lessen the brightness and dial in the picture (it might help but certainly can't hurt)

If none of these remedies (isf you can call it that) work, then the only option is to exchange for a lcd projector or get a dlp with a higher color wheel speed

http://www.avsforum.com/avs-vb/showthread....mp;#post3014215

Victor

Thanks for the very informative post!

Hmmm.. now I must admit I am second guessing my decision to sell everything. I think I might try reducing the brightness with a filter, thanks for that idea - although, perhaps the only real solution is a three chip projector or LCD.

I don't dispute that there is rainbow effect that some viewers have a trouble with. But it is called a rainbow effect as people see rainbow, flashes of light etc... Lucky Me hasn't mentioned any issues with the image just eye strain and or headaches, so this doesn't sound like rainbows, more like simple eye strain. Turn down contrast, turn down brightness, increase room lighting, project on longer throw wall seems like a more appropriate answer.

Try turning on some low level lighting in you room. Only enough that it doesn’t take away too much black levels. Maybe to your left and right. It could be that your eyes don’t like the sudden light transitions. Adding some ambient lighting may be enough to close the irises in your eyes so they don’t need to stretch as far. See if it helps?


DJ

I have heard that the color wheel can cause headache and eye strain as a side effect even when the rainbow effect isn’t noticeable.

DJ

No it is the rainbow effect. On certain projections, I think it is dvd's and movies - if I move my eyes quickly I see flashes of red and green. However It seems that I can't make this happen when projecting from the computer but it still seems to hurt my eyes. I played a game on it again last night and there was no rainbow effect just eye strain.

Oh, I am also not using a screen just a semi-gloss tan coloured wall. I don't have a neutral density filter here but I do have a heat absorbing filter that eats some light. Placing that in front of the project seems to ease the pain in the eyes.

Perhaps I have two problems, one is the rainbow effect during movies and the other is simply too bright of a projection. I wonder what strength of ND filter I should buy? I didn't see many options at Surplus Shed or Anchor Optics, but I did see one that was 75% transmissive, perhaps thats the one, or maybe I should just buy a gray screen?

Well, here's my 2 cents worth. My DIY does not bother my eyes. I also own an older commercial unit which is also LCD, a Sharp® XG-E1000U, the North American version of the XG-3900E (in their day a top of the line $9000 projector). The commercial unit is a little brighter and does sometimes bother my eyes. I'm not sure if it's the extra brightness, or if the commercial unit has less UV protection. My understanding is that commercial projector bulbs produce UV rays as our DIY PJs do, even though they may be called UHP or some such. All that being said, it may just be the brightness bothering you. I guess more experimentation is in order.

Here is more info on nd filters.

http://www.avsforum.com/avs-vb/showthread....mp;#post8678163

Victor

If it ids the rainbox effect then I'd sell the DLP and get a LCD, why make it dimmer to solve the problem with the DLP technology when you could get a bright LCD. I checked on projectorcentral.com which some times lists the color wheel type buit not for your PJ. Older DLPs used single speed color wheels with 3 colors, newer ones use double, triple or quad speed and/or increase the color segements to 6 or 7 like a inkjet does for higher photo quality. People who have a problems with the rainbow effect will have problems with single speed and less with double, and almost no problems with triple speed. I see that your PJ was sold in 2003-2005 so maybe a newer model would solve the problem, but LCD would definately be a safer bet.