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Technical question for ISF calibrators

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Old 30-09-2009, 10:29 AM   #1
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Technical question for ISF calibrators

This one has been going round my head for a while, so I thought I'd seek some expert opinion from the likes of Gordon & co.

How does a viewing environment change the calibrated settings of a PJ?

Perhaps I need to explain the question more fully. Here goes.

Let's start with Contrast and Brightness. Now my room has the dreaded white walls and ceiling, and this has some impact on contrast. However, when setting brightness for the projector, when you look at the colour ramps I can still distinguish the black (video black) bar from the one next to it, which is the correct way to set brightness. Similar for contrast with the whiter/white bars.

Now my understanding (and this is where you might have to correct me) is that these are the correct settings for brightness and contrast. You should not set the PJ differently; otherwise you'll lose fine detail in the darkest and brightest areas, or introduce a lot of unwanted video noise.

So, you set the brightness and contrast correctly, and if your room has white walls, well you've just got to live with the limitations they impose. Meanwhile, after my recent calibration, if I were to paint the walls black, the brightness and contrast settings are correct as they are, and I'll just get a better picture, in that I’ll see more detail in the darker areas.

Similar thing should be the case (again as I understand it) for colour saturation and sharpness.

Now, if I were to paint my walls pink, I can see that might be an issue. Light would bounce off the screen on to the walls/ceiling, and then bounce back at the screen giving it a very slight pink tinge. Subsequently the individual RGB settings may be slightly different. But if I paint the walls a darker shade of grey, the only difference would be that less light bounces back, but the colour of that light wouldn't be different.

Meanwhile, if I paint the walls a dark colour, like dark blue, very little light should bounce back to the screen anyway, and the impact of the colour (in this case blue) should be fairly minimal.

Anyway, I may have a lot of that wrong, but that's why I'm asking the question.

Over to you guys.



Steve W
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Old 01-10-2009, 7:24 AM   #2
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Re: Technical question for ISF calibrators

I would pretty much agree with your assumptions.
You could adjust brightness differently for different conditions but as you say, you can just create other image problems. The whole process is balancing compromises....

G
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Thanks from:
Pecker (01-10-2009)
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