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Author Topic: Shadow Warnings  (Read 1678 times)

Alun

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Shadow Warnings
« on: July 19, 2015, 06:55:12 am »

The blue shadow warnings in C1 are very intermittent for me. Only very occasionally do they show pixels which are black whereas the red highlight warnings work all the time.

Even when I crank the exposure right down there's nothing? Is there something in the Preferences that I need to change?

Many thanks in advance
Alun
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LDJ

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Re: Shadow Warnings
« Reply #1 on: July 21, 2015, 04:59:53 am »

Hi Alun

You are not alone with this issue. Try setting your shadow warning level to 2, rather than 0, and you should start to get reliable warnings. For some reason, C1 Pro does not indicate shadow clipping when level is set to 0. This problem has existed for many years and I have submitted more than one support case, but without resolution. To be honest, values below 5 will appear as black anyway (certainly in print). On-going 'quirks' such as this contribute to the love/hate relationship I have with C1 Pro...

Hope this helps

LJ
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Alun

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Re: Shadow Warnings
« Reply #2 on: July 21, 2015, 06:59:58 am »

Many thanks LJ - let's hope they fix it someday....
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Bart_van_der_Wolf

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Re: Shadow Warnings
« Reply #3 on: July 21, 2015, 07:17:03 am »

Hi Alun

You are not alone with this issue. Try setting your shadow warning level to 2, rather than 0, and you should start to get reliable warnings.

That's right, increase the threshold and clipping indication will be able to show lost information.

Quote
For some reason, C1 Pro does not indicate shadow clipping when level is set to 0.

Technically that is correct, because R/G/B zero doesn't mean it is clipped, maybe it's just zero. The lowest signal levels will have relatively more noise, to the point that the noise threshold exceeds the detectable signal levels (significant noise level above and below the signal level). So it is hard to say what is clipped signal, and what is noise. So by deliberately stating that the signal threshold should be above zero, we will have some signal (and noise) that is lower than that, and it can then be labeled as 'clipped' if below.

An output clipping indicator is not the same as a threshold indicator. And there is also the issue of Gamma, a linear gamma (Raw) signal of 1 (in 255), may be 20 (in 255) after gamma 2.2 precompensation. So it also depends on what exactly triggers the indicator and at how many bits of precision it is calculated. If 14-bit accuracy were used, due to the 14-bit Raw sensor signal, then 1 would roughly be 3 after gamma precompensation, and at 16-bit precision it would round up to 2.

Cheers,
Bart
« Last Edit: July 21, 2015, 07:32:05 am by BartvanderWolf »
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