CurtPalme.com Home Theater Forum

cyclop · Joined: 20 Mar 2009 Posts: 16

Hello Everyone.

Just recently I acquired this projector: Runco DTV-933. After numerous hours I managed to properly set it up  ; must admit it was a bit of a learning curve Very Happy

. Anyways, to my disappointment watching it bothers my eyes. I tried different media and sources with no luck. I ran the projector using bundled in video processor with DVD player, laptop and Blu-ray using HDFury with same results. I also own an old single LCD halogen driven PJ (EzPro CTX 550) with poor contrast ratio and very bad color reproduction, I can watch it for hours with no issues. Also I should mention that my friends Sanyo PLV-Z1 bothered my eyes as well. I was under impression that CRT projectors are easiest on the eyes, true color reproduction, smooth movie like motion and no artifacts. What could be causing my problems?

Thanks in advance.

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

How close are you sitting to the screen? What sources did you try, exactly - and what resolutions / refresh rates? Progressive or interlaced?

Usually CRTs are very easy on the eyes - even compared to CRT monitors at the same refresh rates (48hz progressive on my Barco flickers a bit but is perfect for movies; obviously on a CRT monitor it would be unusable!). So what you're seeing is a bit strange!

cyclop · Joined: 20 Mar 2009 Posts: 16

I know this is strange; nobody else in my family is having this problem. My screen size is 100" horizontally 16:9; I'm sitting approximately 11' away from the screen. My setup was the same with the old projector. Projector is running at 60Hz horizontally, which should be plenty. I'm wondering if this is perhaps related to the flickering of the screen. What would be the highest horizontal frequency I can use with 50 MHz bandwidth? What would be my most efficient resolution setting with?

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

You might want to go see an eye doctor.

Nashou66 · Joined: 12 Jan 2007 Posts: 16171 Location: West Seneca NY

I agree that you should go see an Eye doctor, do you also get head aches when outside in bright light environments and do you like having the lights dim when indoors? I bet your older PJ is very dim and that is why it doesn't bother you, and the runco and your friends do.

I have a friend who has this condition, she actually has to put a window tinting film over her TV to watch it.

Athanasios

cyclop · Joined: 20 Mar 2009 Posts: 16

I don't think I have issues with brightness. I can watch any other kind of TV that I own in total darkness with on problems. It appears that problem is only related to the projection. Old projector is surprisingly bright and very comparable to the Runco. It got very bad screen door effect (800X600 native resolutions), low contrast ratio 150:1 and overblown reds; but no eyestrain. This is very puzzling, looks like I will be checking my eyes very soon even thou I don’t think I need glasses. My vision is fairly good during the day or at night. This sucks, I was really looking forward into me new hobby.

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

**Curt Palme** · Posted: Fri Mar 20, 2009 2:08 pm Post subject:

Funny, I remember when there were buckets of posts about eyestrain with digital projectors, never one about a CRT!

cyclop · Joined: 20 Mar 2009 Posts: 16

My initial setup was: DVD player component to Runco DVP-933 processor the 5 BNC to projector. I believe that DVP-933 outputs 720p 60Hz. Then I tried my laptop with Power Strip at 1024x768 60Hz and 1280x1024 60Hz. My last attempt was Sony Blu-ray 720p and 1080i with HDFury green version.
A projector is sharp and clear, best results I got with Blu-ray and the laptop, DVP-933 is outdated and not as sharp.
All the above give me eye fatigue. My 32” LCD TV or my old CRT 36” TV no issues. My parents own older Sony CRT 60” RPTV I can watch that with no problems either.
I don’t see any flicker at 60Hz but who knows maybe my iris can pick this up and I don’t even know it. I work as a computer programmer, so I use to spend allot of time in front of CRT monitors with on issues, but I was always making sure that my refresh rate is at least at 70Hz (I can see CRT monitor flicker at 60Hz). Can this projector be used with 720p at 72Hz? Will 50 MHz bandwidth limit allow that? I don’t have very good understanding of video calculations as of yet so I always tried to use standard resolutions.

cyclop · Joined: 20 Mar 2009 Posts: 16

Curt, this was one of the reasons I got the CRT projector, nobody compliant about eyestrain.

jkruger · Joined: 24 Oct 2007 Posts: 2435 Location: Carlsbad, CA

cyclop · Joined: 20 Mar 2009 Posts: 16

Well, I tried resting my eyes for few days and I get same results. Also I tried some bias light in the room with no luck. Optometrist here I come.

**Curt Palme** · Posted: Fri Mar 20, 2009 2:49 pm Post subject:

I've got it! You're Cyclop. You only have one eye! Very Happy

perisoft · Joined: 29 Aug 2007 Posts: 2920 Location: Ithaca, NY

Try running at 72hz - or, hell, try 80hz if the PJ will sync. It might not be good for watching movies, and it might be blurry, but at least it might help you narrow down the problem.

cyclop · Joined: 20 Mar 2009 Posts: 16

Curt, that was a good one. that gives me another idea, I will try to block one eye and see if that helps:)

Ile · Posted: Fri Mar 20, 2009 3:27 pm Post subject:

Test with higher refresh rate, brighter picture with 60Hz flickering can cause this.

I can't watch 50/60 Hz flickering either.

cyclop · Joined: 20 Mar 2009 Posts: 16

I will be cranking it up above 70 Hz tonight. Question, is pixel clock the same as projectors bandwidth?

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

try to replicate the problem using a crt monitor, drop the refresh rate play around with it see if you can replicate and get to the heart of the problem, it will be easier to do it like that instead of the projector, once you know what the problem is its a lot easier to deal with. At 60 on my crt monitor I get a headache, at 75,85,90,100 its great, at 43 you cannot watch it. As some others have said check your eyes out as well you may be short, long sighted which will cause a strain, I have astigmatism which is a real pain. Check your eyesight against other peoples if you want to, get a sign and check the range of your eyes vs theirs etc if you want a quick test. Also check if your eyes are dry, there have been various studies showing that if the eyes are dry the muscles cannot change their shape fast enough, I will try and find you the link for the study in Cambridge. Last but certainly not least, try dropping the resolution of the pj, what are you running it at, try it on your monitor first, at 1080p on my monitor my eyes cannot handle it without glasses, even then I don't like it, good luck mate.

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

I think a Runco 933 is a NEC 6PG Xtra isn't it? 720P@72Hz should be fine, hell I ran 720p@72 on my Barco 800G.

Mike

cyclop · Joined: 20 Mar 2009 Posts: 16

Well, I was playing around with different frequency's using power strip and as it turns out I think i killed my Red channel. I don't get anything from my red tube, except bright red output. No text no video. I guess i don't have to worry about my eyestrain for a while.