Improving black......

Discussion in 'Displays' started by AndyGas, Aug 10, 2005.

  1. AndyGas

    AndyGas Extra

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    Have recently upgraded from a 350 lumens LCD projector to a 1100 lumens projector with 0 hrs on the bulb.

    The contrast has improved vastly and the image is sharper due to the higher resolution but I'm having a problem with blacks. The brighter bulb has made them significantly more grayish and whites are too white unless I turn the contrast down (which again makes the blacks worse)

    Now, I know that you can't get real black on an LCD projector but it is possible to improve things slightly by using various filters. I've read on here about the use of neutral density filters which lower the brightness slightly to create a better dark image?

    I have a feeling that this is the avenue I need to take since on bright scenes my front room lights up like a Christmas tree and dark scenes are not dark enough!

    Anyway, does anybody know anything about these filters - like do they come in different strengths? If so, how would I know which one to buy.

    Are these neutral density filters made of the same stuff that VDU screen anti-glare filters are made of? I have one of these lying around spare and was going to encase my projector and use the anti-glare filter as a window for the projector to shine through.

    Would I get a similar result from the anti-glare filter as one of these neutral density filters?
     
  2. ChrisWiggles

    ChrisWiggles Producer

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    An anti-glare filter is usually clear, so it' won't reduce light output at all. The point of a neutral density filter is that it's gray, and reduces light output. They come in different strengths, and how strong you want depends on how much dimmer you want your image. You also may want to experiment with a couple different strengths. I'm a CRT guy so I don't know the specifics on where the best places to get them are. I know you can get glass ND filters, and also cheapie ND filter material, like plastic stuff and cut it out, but this can reduce your ANSI compared with the specific-made glass ones.
     
  3. Victor Ferguson

    Victor Ferguson Stunt Coordinator

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    You could check into a getting a screen that has some gray to it to help contrast. This will intern hurt you whites though. LCD's are very bad for not having good blacks. DLP's are a bit better but still not as good as CRT's.
     
  4. ChrisWiggles

    ChrisWiggles Producer

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    A gray screen will not improve your on/off contrast ratio. It can have a similar function to the ND filter in lowering the amount of light coming off the screen to decreas both your black and white levels equally. A screen is a passive device it can do nothing to increase your on/off CR. Nor can a filter. It just adjusts the light output.
     
  5. Allan Jayne

    Allan Jayne Cinematographer

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    Would you consider painting the ceiling a dark color? By covering or repainting light colored features of the room combined with going with a gray screen you can bring out shadow details in the movie better.

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

    AndyGas Extra

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    Unfortunately I can't paint the room black as it's not a dedicated home theater room. It doubles as a lounge.

    I've told the wife that if we ever move I'd like a house with a suitable room I could dedicate to ht - spare room/suitable loft/big garage.

    Until then though, I'm stuck with the lounge. [​IMG]
     
  7. Evan M.

    Evan M. Supporting Actor

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    What kind of FP is it. Even though it says you are getting 1100 lumens......you are not. Unless it is in a presentation mode but for HT you want to operate it in a low power mode. It sounds like you need a ND2 filter to bring the FTL down to where it should be......about 12......for HT use. Look into maybe a Hoya ND2 filter. They go for about 35$ and will cut the light output in half. Make sure you recalibrate everything after you put a filter on. The other cool thing about the filter is that after while you bulb will start to lose its' oomph. Take off the filter and it is almost like you just got a new bulb LOL!
    I would get the filter before I go the grey screen route as well.
     
  8. AndyGas

    AndyGas Extra

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    The projector I've got is an NEC Multisync MT1030+. Compared to the old Litepro, resolution is brilliant and the screen door effect isn't noticeable unless you're right up close to the screen.

    Will have a look into the Hoya ND2 filter that you mention. Thanks for the advice. [​IMG]
     

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