Trinitron CRT G2 voltage adjustment with grayscale pattern in WinDAS. Crush blacks? - AVS Forum
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post #1 of 3 Old 11-17-2013, 12:35 AM - Thread Starter
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I'm using a software called WinDAS to hardware calibrate my Sony Trinitron monitors (FW900's and an IBM P275). The software can interface with a few video signal generators, listed in this confidential sony bulletin. However, as I don't have a signal generator, I'm using my geforce GTX 660 as a software signal generator.

At one point during the white point balance procedure, it asks to display a grayscale pattern, and adjust the G2 voltage (with a slider control) until the first black bar blends in with the adjacent dark gray bar.

I found the manual for one of the supported signal generators, and found a reference to a graybar test pattern. I'm assuming this is what WinDAS is asking for. See image below:




Now if I'm understanding all this correctly, it's asking me to crush 7% input signal with 0%. I can understand why you would do this if you're calibrating for 16-235. But I'm calibrating for 0-255, and as far as I understand, WinDAS is designed to calibrating CRTs in a computing environment.

Am I misunderstanding something here?

(one possibility is that it will readjust the G2 level at some later point in the process to compensate, and that getting the user to manually crush it is just a reference point. I'll have to go through the entire procedure and test the outcome to be sure).
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post #2 of 3 Old 11-17-2013, 01:04 PM
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Well doing that, would help you establish where the minimum black level is.

But after doing that, turn it back up. 7% should be significantly visible against 0%.

Joel Barsotti
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post #3 of 3 Old 11-17-2013, 01:40 PM - Thread Starter
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thanks. I'll do some experimentation and report back.
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