DLP rainbows

Discussion in 'Projectors, Screens & Video Processors' started by Jim McC, Apr 6, 2004.

  1. Jim McC

    Jim McC
    Standard Member

    Joined:
    Mar 28, 2004
    Messages:
    64
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Location:
    Wisconsin
    Ratings:
    +0
    Why do rainbows affect some people and not others? Is there an optometrist out there?
     
  2. TT9

    TT9
    Guest

    Products Owned:
    0
    Products Wanted:
    0
    Ratings:
    +0
    I've noticed a definite identifiable relationship between buying power and susceptibility.

    . . . 'The HT300 gave me headaches and I saw rainbows so I bought a Z1'. . .
     
  3. docfeelgood

    docfeelgood
    Standard Member

    Joined:
    Sep 9, 2003
    Messages:
    237
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +1
    TT9.... I can see the rainbow effect very easily. In fact on one occassion it was so bad that I felt sick. After I had finished the demo I could still see the rainbow artifacts when I blinked !

    This was from a PJ I wanted to buy... and had the money to buy... I was gutted.

    The problem exists for many people who are sensitive to it.

    It is misleading to imply otherwise.

    I would be very dissapointed if I spent 3k on a nice DLP only to get it home and not be able to relax and watch it.

    Then there's friends and family. How do you know if they are sensitive to this. Not much cop if no-one else will watch a movie with you because 'it makes them feel sick and dizzy'.

    Firstly... make sure you demo a DLP in proper conditions.
    Secondly.. are you likely to be using this alone? ... if not then take along some of the people who will be watching to the demo.

    cheers
    :)
    Doc
     
  4. uczmeg

    uczmeg
    Active Member

    Joined:
    May 18, 2003
    Messages:
    3,498
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    71
    Location:
    Nottingham
    Ratings:
    +67
    I agree with Doc, demoing DLP is a must.

    Not all DLPs are equal, so try and demo the one you are most interested in. Or if you really want to be sure demo something cheap like the Infocus X1 with it's slower colour wheel. If you are OK with that then you are OK with anything.

    Once I'd seen that the wife was fine with DLP and how much nicer DLP was over LCD I thought, sod the friends. 95% of the watching is just the two of us. I'll take the chance on the rest of them! ;)

    Luckily the dozen viewers so far have been fine.

    Cheers
    Marc
     
  5. SanPedro

    SanPedro
    Well-known Member

    Joined:
    Jan 11, 2001
    Messages:
    4,536
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Ratings:
    +521
    Cheaper DLPs are more noticeable. I've seen the Sim Domino 20 and didn't see a thing untoward. Some cheaper machines have been quite noticeable from my experience.

    I'd guess that within 18 months - 2 years (maybe sooner), as the faster colour wheels filter down to the cheaper models then rainbow will be less of an issue to most peple.

    CL
     
  6. gizlaroc

    gizlaroc
    Well-known Member

    Joined:
    Jul 26, 2001
    Messages:
    9,373
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    Norwich
    Ratings:
    +895
    Although I dont suffer too badly from rainbows, I do get a headache from DLP units, I find myself frowning after 45 minutes or so and it starts to really hurt after about an hour and a half.

    So it would be advisable to get as long a demo as possible.
     
  7. Clint C

    Clint C
    Active Member

    Joined:
    Dec 10, 2002
    Messages:
    425
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Wiltshire UK
    Ratings:
    +4
    When I first got my HT1100 both me and the misses felt nausea creeping on. After getting advice from this very forum I found that the nausea is eliminated by sitting no closer than 2x screen width. This has to be to do with not having to scan your eyes across the picture so much when sitting too close which would in itself bring on the rainbow effect... let's face it, when you want to induce the rainbow effect people suggest wiggling your eyes left and right in dark scenes with areas of "light" in. So for me and the misses sitting further back means that the picture is still large but a whole lot more enjoyable from this wonderful DLP projector.

    Clint.
     
  8. Peter Parker

    Peter Parker
    Distinguished Member

    Joined:
    Apr 6, 2001
    Messages:
    13,561
    Products Owned:
    1
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    UK.
    Ratings:
    +3,061
    Hi Jim,

    Are you a regular poster over at avs? If so, is your room carpeted from floor to ceiling in grey carpet, and do you have black indoor/outdoor carpet on the screen wall?

    Gary.
     
  9. G a f f e r

    G a f f e r
    Moderator

    Joined:
    Dec 31, 2003
    Messages:
    3,031
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    136
    Location:
    U.K.
    Ratings:
    +645
    everyone has different susceptibilties to dlp. Good idea for a poll?

    ps, yes they do bother me, but even though noticeable, less annoying on sim2 domino20
     
  10. Jim McC

    Jim McC
    Standard Member

    Joined:
    Mar 28, 2004
    Messages:
    64
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    6
    Location:
    Wisconsin
    Ratings:
    +0
    To Gary, I do post on that forum, but the answer is no to your 2 questions.
     
  11. LV426

    LV426
    Administrator Staff Member

    Joined:
    Jul 14, 2000
    Messages:
    13,576
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Somewhere in South Yorkshire
    Ratings:
    +6,097
    I have to guess (not being trained in such matters) that it isn't exactly an optometrist question since it isn't (I think) about focus or optical sensitivity per se but more about the speed with which either your eyes or brain can detect changes in what you see.

    Long before DLPs and their rainbows, long before widescreen TVs, Sony produced a 29 inch (4x3) TV with 100hz.

    Walked into the local Sony Centre with my colleague. Immediately I can pick out the 100hz TV - the lack of flicker is immediately obvious to me. Whereas, he doesn't have a clue what I'm on about.

    10 (?) years later and he now admits he can see the difference.

    Visibility of CRT refresh rate flicker and rainbows is, I suspect caused by the same thing - can I call it 'fast eyes'? And, my sevsitivity is certainly getting worse (ie more sensitive) as I age. The evidence from my colleague, starting from a less sensitive point, is the same.

    And the pojnts made by others here are well made. At worst, you see, and are nausated by, DLP rainbows almost immediately. At best you have no idea what the problem is. In between and you may find yourself becoming 'tired' or uneasy at watching - without being able to detect exactly why.

    As for keeping your screen size small and/or staying far enough away from it to avoid lateral scanning to keep rainbows at bay - this is surely tending towards defeating the whole point of home cinema - to get (close to) a cinema-like experience in the home. Rare, I think, to go to the cinema and not have to laterally scan a wide picture. Might as well buy a TV?

    Roll-on 3-chip DLPs at realistic prices Until then, it's LCD (with its greyish blacks) for me - no contest.
     
  12. Clint C

    Clint C
    Active Member

    Joined:
    Dec 10, 2002
    Messages:
    425
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    21
    Location:
    Wiltshire UK
    Ratings:
    +4
    Nigel, sitting 1.5 to 2x screen width back isn't that unusual... It's what most people recommend. I just happen to sit 2x screen width back to get over my DLP viewing problem. So from 12 foot back I look at a 6 foot wide screen... still looks big to me and much better than watching it on my tv. Oh and did I mention how nice the blacks are? :D
     
  13. LV426

    LV426
    Administrator Staff Member

    Joined:
    Jul 14, 2000
    Messages:
    13,576
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Location:
    Somewhere in South Yorkshire
    Ratings:
    +6,097
    Indeed. In my case, I sized my screen according to the largest size I could fit into the space available - it is 8 feet wide or thereabouts. And I sit about 12 feet back. Too close, I think for avoiding lateral scanning.

    My point was, that I wouldn't consider using a smaller screen (to circumvent the rainbow issue) as being preferable to the (admittedly) greyish blacks - but otherwise artefact-free image I get from my LCD. My next projector (given the current state of the market) will be another LCD.

    Actually, I doubt even with a 6-foot screen at this distance, I'd not have a problem with DLP.
     

Share This Page

Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice