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I know that this will sound strange...but has anyone experienced headaches after wathcing a DLP for a few hours? Could I be experiencing a problem with "rainbow effect" or some other motion artifact?


Thanks,


CGM
 

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watching 5 hours of LT150 (DLP) for the first time. This is my first long term viewing of a DLP and I started experiencing heavy eye strain after 1-1.5 hours. I did see a few rainbow effects here and there but they weren't that noticeable. Now that I am done for the evening, I have quite the eyestrain enduced head ache.


I don't think DLP is the way for me to go. I'm going to try a VT540 or LT155 this weekend.
 

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There has been mention in some posts of an effect caused when the field of vision contains to great of a contrast change. The example I remember dealt with the surrounding ambient light vs that of the screen.


Basically I believe the argument went something like this: If the ambient was too low and also occupied a fairly large portion of the field of view then the contrast between the low light surrounding the picture and that of the movie caused the eyes to continually shift aperature.

Whereas when the field of view for the movie was enlarged such that the dark area percentage of the field of view was reduced, the eye strain did not occur.


So turn on very dim light or make the picture bigger. So some say.


My take - if your eyeball is autoranging a lot it gives you grief.


On the gripping hand, this probably has nothing at all to do with this thread.
 

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I did experience eye strain with the LT150 using a JVC progressive scan DVD player.


I also experienced some eye strain (but not as bad as the LT150)with a VT540 using the same DVD player.


However, I had no eye strain with a Sanyo PLV-60 and same DVD player.


The the case of the LT150 I think it was a combination of rainbows and artifacts due to poor internal scaling. With the VT540, it was probably due to artifacts by internal scaling.


I think I'm one of those people who has a critical eye and both my eyes and brain try to work together to counteract the 'imperfections'. "Golden Eyes" is what some industry people call us.


I'm a bit sensitive to screendoor as well. However, slight defocus of the Sanyo corrected the problem and given the source was 470p lines scaled to almost 700 pixels, then the defocus did not cause noticable degradation. In fact I find I perfer a 'softer image' over a razor sharp image.


Ray
 

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exactly as I would describe it. :)


I woke up this morning feeling the eye strain still (after 5 hours of watching the DLP LT150 last night and getting mega-eye strain).


Jamin, I was watching in a dark room with a 100" diagonal screen from 12 feet. I think that is a big enough screen size to not get the effect described by you.


I was watching in on an older Toshiba Interlaced DVD player and it was crappy viewing experience. Jaggies were ever present. Rainbow was minimal for me, perhaps because I was projecting onto a ultra white painted wall not a hi gain screen.


While this was my first exposure to DLP, I agree with Radar that I must have a very sensitive/critical eye and there was just too much crap on the screen for my eye&brain to deal with. This must have led to the eye fatigue.


I phoned my sales rep at http://www.advanced-inc.com/ and I described my problem with the LT150. They are not really geared for HT consumers and don't have a consumer friendly loaner policy. I would like to look at the VT540, but am not encouraged by the eye fatigue that Radar describes looking at it. But I'm not going to pay $300 to rent it for an evening just to try it out.


I do need to upgrade my DVD equipment before I do another demo, because interlaced does not cut it on a big viewing area.


Oh well, I was kind of disappointed by the viewing experience. An impressively large movie picture but a lot of negative also-- at least with the LT150. I have to wait until my eyes recover from this viewing experience before I move on. THis is going to get very expensive if I pursue FP for movies. I think my eyes are very sensitive and getting the right projector will take a lot of trial and error--- difficult with the lack of retailers willing to loan you units.


- JP
 

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I've experienced this as well. Not only with projectors but also with RPTV's.


The answer is a 6500k fluorescent behind the screen.


You can find these at Pet Stores that sell aquariums. Make sure the bulb says 6500k. I bought many that said daylight or someting like that and every time we tested them with the analyzer they were no where close.


The theory here is that the 6500k light behind the screen (that way it doesn't affect the image from the front) is that your eyes don't have to work so hard to adjust from dark to light. It's like what happens when someone suddendly turns on a light in a dark room.


I always thought it was hogwash, but it really works. Also I swear, althugh I can't prove it, that the colors look better and the images are crisper. It might have something to with eyes not working so hard.


Anyway it cost about $20 to $25 for the experiment. Who knows it may work for you as well.
 

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like my room was way too dark. I will keep it in mind. This is quite a learning process.
 

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Think of what it would be like to watch a 5 hour movie in the theater. FP is more like that experience than watching a 27" tube.
 

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I have never experience anything like that in a movie theater. NEVER. As I write this now, 2 days after watching, I still can fill the eye strain!!! I felt the initial eye strain while watching DLP 1.5 hours into the session.


I have never even felt anything close at the movie theater, at 2-2.5 hours of viewing. I have also watched movies back to back at a theater, for a maximum of 4 hours of movies watching. Again, there was no eye strain.
 

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I have had similar eye strain with even a 19" monitor....


I think it's just your eyes needing to adjust.


I never had eye strain at the theater either............


Aboviously your eyes MAY not be"familiar" with the image, either size, brightness, resolution, or the amount of motion on the screen (i.e.movies vs. video games) is wearing out the muscles that control the movement of your eyeball and socket.


Trust me.


You may not like DLP, and I cannot blame you, but you may as well go ahead and get the eye workout, cuz your gonna need it.

The more you watch it, the more adaptable and strong your eyes will become...


Remember, that which does not kill you makes you stronger...


I had to get "used" to my 61 inch RPTV, I had a few relatives that felt motion sickness in the first few minutes of viewing (mind you they were all used to 21-27inches) and I personally thought I was gonna puke the first few seconds of watching the Omnimax in Chicago...


Methinks it is something you will have to get used to, it's your eyes "moving" due to the size of the screen. If you are having to look left and right to follow the action of a movie, you will eyes muscles will wear out, because that just like jogging or lifting weights or ANYTHING that would make you tired.... When your eyes are better, go back, and see... Eye muscle wearout can feel like a migrain headache............. Your eyes may be darting left-righ-up-down.........


If it's still there, get some more rest!!!
 

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I've been thinking more about this (naturally, since I have the 9000 on order, I'm now worried about everything;)).


When I initially auditioned the 9000, I watched it for at least an hour straight. Later, when I was offered the opportunity by an AVSer to check out his LT150, I think we probably spent 2-1/2 hours watching various content. I then went back to look at the Sharp and spent a good 2+ hours watching it.


On none of these occasions did I experience any discomfort, fatigue or strain. I left these occasions feeling fine and having throughly enjoyed the experience.


However, on two recent occasions I have dropped in on the dealer to take a peek at the 9000, and experienced a little eye strain on very brief viewings (10 minutes or so).


I doubt, therefore, that this phenomenon is specific to the projector or to DLP per se. Rather, I suspect that it may be either environmental (like the room and screen combination) or physical (like, I'm very tired lately and therefore maybe more susceptible to fatigue).
 

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The only time I experience this is when I drink to many beers during the movie.
 

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It sounds like the dlp projectors should carry a warning from the surgeon general.
 

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Quote:
Originally posted by CGM
I know that this will sound strange...but has anyone experienced headaches after wathcing a DLP for a few hours? Could I be experiencing a problem with "rainbow effect" or some other motion artifact?
After demo-ing a DLP for 20 minutes.. I had a head-ache, felt dizzy and nearly threw up. I'd suggest that I'm at the extreme end of sensitivity to DLP's.... but eye strain is nothing strange. My wife whilst not feeling sick.... her eyes did feel very fatigued.
 

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When it comes to 3 chip dlp, the reply to your suggestion is:


Nonsense.


I once pointed a Camera at Ocean Drive from my lab in South Beach, the ocean view on the 3 chipper mounted in the backroom was awesome, a few viewers came to the conclusion that one would actually get t a headache when walking out on the real beach. Reality gave the headache, dlp the cure...
 

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I've had one of the first DLPs since it came out in 1998, PLUS UP 800. There is one thing people seems to forget about DLP, they were created to show a progressive image.


Feeding a DLP with an interlaced signal is a really awful viewing experience. Your eyes will not be relaxed when watching the picture.


The solution is to get yourself a linedoubler.
 

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Everyone....This eye strain/headache IS DLP.....Like a poster said, "it's too much information for your brain to process"....I too, am sensitive to this type of projector, and hope that the next generation of 1 chipers are better....Unfortunately, I believe that the problem will not be cured until the 3 chipers come out for us "hobbyists". Maybe these DLP companies should include some Advil in the box. My LCD is watchable ALL DAY.....
 
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