contrast, brightness, gain, and my quest for a darker black

Discussion in 'Archived Threads 2001-2004' started by Peter.LeBlond, Aug 6, 2002.

  1. Peter.LeBlond

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    I will go ahead and admit that I might be trying to do the impossible, but I am not expecting a reference quality image. I'm just wondering if there is anything I can do to improve over what I already have. That being said....
    I am wondering if someone could explain the relationships between brightness and constrast to me a little better.
    First the physical brightness vs the contrast abilities of a projector. I've heard that Piano chose to go with a lower light output (450 lumens) to get a better contrast ratio compared to most other projectors of that class (most have 1000 lumens or so). Then there is screen gain. The higher the gain, the whiter the screen, the brighter the image looks, but the lower your contrast? So it seems to me that you would want a high gain screen for a low light projector?
    I guess my biggest misunderstanding is this. I have my Piano farther from the white wall I am using as a screen than I should and am projecting an image about 50% bigger than recommended. I then set the picture controls to those as mentioned in a review in Stereophile (I think). I was thinking that this would end up giving me perhaps a darker picture but I ended up with a washed out, but pretty bright image. I really wouldn't mind the image that I get if the blacks weren't so bright gray. How high can I set the contrast control? What does boosting the contrast compromise?
    I have to take down the projector sometime in the near future to send it back to Plus to get rid of a dead pixel (they are being really cool about that [​IMG] ) so I will try setting it up at least temporarily for the the recommended 80" screen size and see what I can do about this picture.
     
  2. Neil Joseph

    Neil Joseph Lead Actor

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    Why don't you try moving your projector around. Try placing on top of a table and move the table around, taking note of the PQ, screensize etc. What sie are you currently projecting and how far is the unit from the screen?
     
  3. Peter.LeBlond

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    I am set up 14-15' from the screen and throwing an image of 120". Plus and most every review I have read recommends a distance of 10' giving an 80" image. That being said I am not trying to recreate those results, I was simply trying to get some information to better educate myself as to how brightness and contrast work with projectors; and how the light output and screen gain play their part in image quality.

    I am still somewhat perplexed as to why my image I would best describe as overall too bright, when I am farther from the screen than optimal. Tonight I even tried turning down my brightness/contrast to full negative and sure enough my image was all but gone, but the blackness that was shown was still rather bright gray. Especially when one of the remarks about this unit is its "superb blacks".

    I fully intend on moving my projector closer and experimenting with it at 80", but I would still be very interested if I could get my hands on some more information on the subject so that I can get the best image I can at whatever screen size I am at. Thanks again.
     

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