Projector lumens question

Discussion in 'Displays' started by MikeySmith, Jul 29, 2005.

  1. MikeySmith

    MikeySmith Extra

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    What would you say would be the minimum lumens that I would want if I want a decent projector that will play with lights on and sunlight coming in the doorway.. I don't want to have to turn everything off to watch tv.
     
  2. MikeySmith

    MikeySmith Extra

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    Specific recommendations of projectors would be appreciated.
     
  3. mark alan

    mark alan Supporting Actor

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    no projector will work in that scenario. You cannot compete with the sun. Unless you are willing to ensure dim light at all times, DO NOT get a front projector.

    By dim, I mean just bright enough to read, like one 60 watt bulb away from the screen.
     
  4. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

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    Greetings

    Well Benq's 7700 was actually marketed at the CES as a projector to use in a room with a bit of ambient light. They had a small lamp on for reading ... and a 80 inch rear projected image (froma FPTV) on a second wall showing a bright demo reel and the image still looked "okay." Very watchable.

    If you want it to compete against ambient light ... then add a high contrast screen ... 2.8 gain variety.

    Regards
     
  5. Nils Luehrmann

    Nils Luehrmann Producer

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    There are projectors and screens that can increase the foot lamberts to a high enough number (+50 ftl) such that even in a bright room it wont look washed out, but just remember, 'black' will only look as black as the color of the screen in a lit room. So while a set-up that gives you ~50 ftl will give you a very watchable image in a well lit room, the black level will look light gray at best.

    There is a new technology commonly referred to as 'Black Screen' which DNP developed. In basic terms, it uses a high contrast filter, which only allows the light coming from the projector to be reflected back to the viewing area. In addition, the screen material is black, thus boosting typical contrast levels to as high as ten times that of a normal 1.3 gain screen.

    Screen Innovations here in Austin have developed a screen called Mirage, which is based on this technology:

    [​IMG]

    They had it available for demo last week, but unfortunately I was in Seattle the entire time and so I missed it, a fellow Austin HTF member went and saw it and he seemed quite impressed. CLICK HERE to read his comments.

    These screens are not cheap though, and they are not readily available, but in a couple years I suspect we will see several new screens based on this technology and the prices should come down by a significant amount.
     
  6. JohnRice

    JohnRice Lead Actor

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    My question is, why even bother if you aren't going to set up the environment properly?
     
  7. JohnRice

    JohnRice Lead Actor

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    Nils, that image made me rather suspicious at first, and I still suspect it is, shoud we say, exaggerated. But, after thinking about it for a moment, it is quite possible it uses polarization to significantly reduce ambient light, which would also explain why it appears to be black. I expect they have done something along those lines. It would make it incredibly expensive, but if it works, economy of volume could bring the price down a great deal. The problem is, there would be a loss of maximum brightness and it would probably require an excessively powerful projector to compensate. Mainly a "not other option" type of solution.
     
  8. Allan Jayne

    Allan Jayne Cinematographer

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    Calibration varies with the light level in the room. Even if you could get a projector with enough lumens , when you calibrate it to give a half decent picture for a bright room, the calibration will be way off when you do darken the room appropriately for serious viewing.

    Also, projector lamps and projector internals last longer when you are able to run the lamp at less than maximum power.

    Video hints:
    http://members.aol.com/ajaynejr/video.htm
     
  9. ChrisWiggles

    ChrisWiggles Producer

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    This is your problem. Close the door, you can't compete with sun. You can do with some dim lights, but sunlight is REALLY bright.

    For those recommending high-gain screens, keep in mind that this ONLY helps if the light sources are OUT of the source-cone that the gain focus is sourced from. If the light source is aligned with the projector, it will get all the gain too, and so it won't help any. If it's off-axis, it will help.
     
  10. JohnG

    JohnG Stunt Coordinator

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    also interested in OP's question as I'm somewhat of a noob to the projector game
     
  11. mark alan

    mark alan Supporting Actor

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    the question has been answered. you cannot compete with sunlight. Period. End of story.
     
  12. Nils Luehrmann

    Nils Luehrmann Producer

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    ??? Far from it.

    Actually, you can compete, but it will cost you more and is a compromise over a light controlled environment - but you most certainly can compete. I've seen an effective front projection system used outside while the sun was still above the horizon, with a 120" screen. Ideal? No, but effective just the same.

    In a room as described by the OP, one could design a front projection system that could compensate for indirect sunlight and ambient lighting.

    These systems are designed regularly for sports bars who are not about to block off the windows, and turn off all the lights. [​IMG]

    Here in Austin there are at least three sports bars that all use at least one front projector. While not ideal, all of those set-ups produce a very watchable image that the patrons seem to enjoy as they crowd around them every weekend.

    At home you have an even better chance of competing against indirect sunlight and ambient light because you wont necessarily need to use the large screens used in sports bars. The smaller the screen the higher the ftl.

    As an owner of a dedicated HT I certainly understand the benefits, but I think it is quite unreasonable to suggest to the OP that anything other than a light controlled environment is not only a waist of time, but that it can't be done.

    "End of story" [​IMG]
     

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