1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

DLP Rainbows, eyestrain etc: Front projection V Rear projection

Discussion in 'Projectors, Screens & Video Processors' started by Comer, Oct 27, 2005.

  1. Comer

    Comer
    Active Member

    Joined:
    Sep 21, 2001
    Messages:
    1,365
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +82
    I'm starting to believe that with out the auto-iris trickery, LCD has come to the limit of it's contrast ration capabilities. Perhaps, for me, it's time to change from considering LCD to DLP. My problem is that demoing a front projection DLP is really very difficult here but I do have a friend with a 50" DLP rear projection TV. My question is are the rainbows, eyestrain, headaches etc. more, less or the same on front as rear projection DLP.

    Thanks


    Conor
     
  2. michael.redfern

    michael.redfern
    Active Member

    Joined:
    Oct 14, 2003
    Messages:
    859
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    31
    Location:
    Manchester
    Ratings:
    +91
    Not too sure about the headaches and eyestrain as I couldn't bring myself to watch one for long enough, but I can see RE just as much on a rear as a front pro DLP.
     
  3. BretLuke82

    BretLuke82
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I spent about 6 hours in front of my SP 4805 (DLP front projector) last night. I can definitely see rainbows. But, even after hours of seeing the rainbows, I never got a headache or had eyestrain. I didn't notice them while playing Halo, but they were pretty prominent while watching Batman Begins (lots of dark background with bright light scenes).

    To me, the RBE is a non-issue even though I can see them perfectly.
     
  4. Darko

    Darko
    Well-known Member

    Joined:
    Apr 13, 2005
    Messages:
    3,701
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Caterham on the hill Surrey
    Ratings:
    +173
    NOT THE AGE OLD ARGUMENT OF LCD vs DLP NOOOOOOOOOOOOOOOOOOOOOO
     
  5. Comer

    Comer
    Active Member

    Joined:
    Sep 21, 2001
    Messages:
    1,365
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +82
    Who's arguing? The point of my question is not to compare LCD with DLP, but DLP rear projection with front projection.
     
  6. psflynn

    psflynn
    Active Member

    Joined:
    Nov 10, 2003
    Messages:
    338
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Swindon
    Ratings:
    +4
    i have a DLP front proj. I only now seem to notice rainbows if i move my eyes rapidly from one side of the (large) screen to the other.

    So on that basis , I (personally), would be unlikely to see them on a 50" screen as it would always be within my field of view and my eyes would not need to move by any significant amount.


    Having said this, everybody seems to be different. If you dont see them on a rear-pro chances are you may not see them on a front pro - or if you do they may not bother you too much.

    However if you see them on a rear-pro, then you probably WILL see them on a front pro and it may be all too much!

    No help really, other than to be sure, you need to have a good long extended demo of a front pro!
     
  7. RTFM

    RTFM
    Active Member

    Joined:
    Mar 6, 2003
    Messages:
    1,014
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    38
    Location:
    Horsham, West Sussex
    Ratings:
    +17
    RP is generally brighter than FP so is more inclined to show colour separation with DLP displays.

    Jeff
     
  8. PJTX100

    PJTX100
    Well-known Member

    Joined:
    Dec 21, 2004
    Messages:
    8,129
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +562
    Though the desire to look at DLP options as well as LCD is an eminently sensible one, I find your "trigger" for doing so rather strange.

    If contrast is your ultimate goal you should have been looking to DLP much longer ago.

    In my book contrast is only one of a package of features which a PJ must deliver and shouldn't be taken in isolation...PJ
     
  9. monopole

    monopole
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Firstly, I can see rainbows on front DLP projectors. And they give me a headache.

    Recently I spent some time sitting in front of a DLP rear projection TV (on a cross channel ferry - have no idea what the spec was) and it had the same effect on me. It's not so much the rainbows that bothered me, it was the vice like grip it felt like it had on my head.

    Paul
     
  10. NicolasB

    NicolasB
    Member

    Joined:
    Oct 3, 2002
    Messages:
    5,880
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Emily's Shop
    Ratings:
    +566
    But the eye is more dark-adapted when actually watching FP, so that surely should cancel out...?

    I've a suspicion that a very large display would be more prone to flicker-effects than a smaller one, because the peripheral vision is more sensitive to flicker than the central vision - but, equally well, you can't see colours in your peripheral vision at all, so you probably wouldn't see rainbows. I wouldn't be surprised if eye-strain and headaches were a bigger problem with FP.
     
  11. Comer

    Comer
    Active Member

    Joined:
    Sep 21, 2001
    Messages:
    1,365
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +82
    Thanks for all your contributions. I was really impressed with the picture quality of this RP DLP, in terms of contrast and image punch. I did see rainbows but I'm not so sure how much they would distract me if I was watching a movie rather than demoing a piece of gear. Knowing the kind of person I am, I suppose they would, in time, start to drive me crazy. Also my wife suffers a bit from migraine and eyestrain and perhaps DLP would be problem for her. Right now I've got a buyer for my Z3 offering me a great price but I can't decide if I want to sell. I didn't think that new crop of LCDs will offer me a €700 worth of picture improvement over what I have, so I considered DLP.

    All things considered, I think I'll hold firm for another year with my Z3, wave goodbye to the excellent price I've been offered :( and see if a three chip DLP with 1280X720 resolution, 22db fan noise, shoe box sized projector comes on the market for £999 (with free lamp voucher, screen and promotional family meal voucher in McDonalds)

    A gal can dream can't she (and so can I :D )
     
  12. Comer

    Comer
    Active Member

    Joined:
    Sep 21, 2001
    Messages:
    1,365
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    51
    Location:
    Ireland
    Ratings:
    +82
    Well I just spent an hour watching the RP DLP. We watched Gladiator. The rainbows really were quite distracting, I also developed a pain all around the top of my head as if something was squeezing my head. I experienced this last week also but to a lesser extent as I only watched for about 20 minutes.

    My friend sees no rainbows and feels no adverse effects. I wonder if I'd never visited these forums would I not have suffered these problems also. :rolleyes: Ignorance can be bliss ;)


    Looks like it's LCD for me.
     
  13. organica

    organica
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    Wee bit of DLP experience here.

    When I was first looking at projectors, I experienced the rainbow effect very markedly, to the the extent that it outweighed all other considerations for me.

    However, I was also wanting the projector for use at gigs and live shows, and didn't want the liability of using an expensive machine in crowded venues with dodgy wiring.

    So I got myself a nice, value (and bright) Benq PB6210 DLP, planning to get a more expensive LCD model for my own home use.

    Never needed it. My once highly-distracting rainbow problem has somehow subsided. I hardly see them at all on colour source material now. Black&white films are the only issue, and even then, only in very high-contrast scenes.

    I can't guarantee everyone's brain will do this magic acclimatising trick, but I have heard other people mention it, and the degree to which it has happened to me has been a real surprise. And a delight, cos the basic PQ on the Benq is excellent, saved me a grand on a second projector.

    Minds are weird.

    g k
     

Share This Page

Loading...