Why not use a projector that is "educational"

Discussion in 'Displays' started by Rick Westfall, Oct 11, 2005.

  1. Rick Westfall

    Rick Westfall Stunt Coordinator

    Joined:
    Dec 8, 1998
    Messages:
    220
    Likes Received:
    0
    Trophy Points:
    0
    What are the drawbacks of using a projector that is intended for educational purposes? The specs look just as good as a HT projector. DLP, 2000 ANSI lumens, 2000:1 contrast ratio, etc for a fraction of the cost. See projector specs here. Guide me oh wise ones

    Rick
     
  2. Michael TLV

    Michael TLV THX Video Instructor/Calibrator

    Joined:
    Mar 16, 2000
    Messages:
    2,909
    Likes Received:
    1
    Trophy Points:
    0
    Location:
    Calgary, Alberta
    Real Name:
    Michael Chen
    Greetings

    4:3 aspect ratio on most ... and possible grayscale calibration limitations.

    The scalers built into these units "may" also be less than those found in HT projectors.

    Fan noise much higher though and possibly more light spill from the box.

    Regards
     
  3. Bob_L

    Bob_L Supporting Actor

    Joined:
    May 19, 2001
    Messages:
    892
    Likes Received:
    4
    Trophy Points:
    110
    Real Name:
    Bob Lindstrom
    All good observations from Michael.

    In addition, the higher lumen ratings on educational/business projectors based on DLP technology (like the one in your link) is usually because there is a clear panel on the color wheel that passed more light to create the higher level of luminance.

    However, the additional white light can wash out the image and compromise the color integrity, so for home theater use, you usually "turn off" the clear panel. This will reduce the lumen rating significantly, by half or more.

    That doesn't mean you should overlook those projectors, though. Just see them in operation before you take the plunge.
     
  4. John S

    John S Producer

    Joined:
    Nov 4, 2003
    Messages:
    5,460
    Likes Received:
    0
    Trophy Points:
    0
    Interesting wording at the bottom of the link you provided.

    Min/Max Screen Size 40" - 300" (diagonal, 4:3)
    Min/Max Projection Distance 4' 7" (for 40" diagonal, 4:3) up to 39' 8" (for 300" diagonal, 4:3)
    Other DTV/HDTV compatibility (both 4:3 and 16:9) for use with current and future video technologies.


    Not to sure here about it's 16:9 capabilities as it puts it.
     
  5. KeithMoechnig

    KeithMoechnig Stunt Coordinator

    Joined:
    Jun 25, 2005
    Messages:
    123
    Likes Received:
    0
    Trophy Points:
    0
    I think they're really good projectors if you can get a deal. The fan noise and screen door effects are usually higher, but if you can deal with those, you get a good projector.
     
  6. ChrisWiggles

    ChrisWiggles Producer

    Joined:
    Aug 19, 2002
    Messages:
    4,791
    Likes Received:
    1
    Trophy Points:
    0

    You get what you pay for with projectors at this point, I'm afraid. You will suffer lower resolution, lower contrast, terrible color accuracy most likely due to inaccurate primaries. Everything is usually geared towards light output, which is not at all what is needed for accurate high-quality images. You will find the best HT projectors with the highest contrast, etc, will have low light output in comparison. There are some business projectors that are the same as their HT counterparts, but you won't be finding any deals there unfortunately. There are no "miracle" deals going on by buying business machines instead of HT machines. Best case scenario, you're getting the same projector at the same price. More likely scenerio, you're getting a similar projector at the same price, but with some design options (such as a white segment in the colorwheel) to benefit business applications that are negatives when it comes to HT. worst case scenario, you find a projector that is a lot cheaper, that performs terribly for HT.
     
  7. Allan Jayne

    Allan Jayne Cinematographer

    Joined:
    Nov 1, 1998
    Messages:
    2,404
    Likes Received:
    0
    Trophy Points:
    0
    On this particular model (and any 800x600 or Svga model) when in 16:9 mode the resolution is sub 480p namely 450 scan lines. While the projector accepts 720p and 1080i among other input resolutions, the native display resolution is 800x600 for 4:3 pictures.

    It is debatable whether slight anamorphism in 16:9 programs at 480 scan lines (800x480) is preferable to perfect proportions at 800x450 provided the projector has appropriate adjustments.

    Nothing was said about wheel speed and the resulting amount of rainbow effects. Generally including "white content" (black & white picture; pure luminance; using the clear wheel segment or panel) makes RBE less noticeable.

    Field uniformity brightness wise (is that what corner to center ratio is?) needs to be auditioned.

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

Share This Page