12 vs 14 bits raw files

Started 4 months ago | Discussions thread
OP plumberdp69 Regular Member • Posts: 367
Re: 12 vs 14 bits raw files

beatboxa wrote:

I don't think that i understand this question. At base ISO, the camera has potential to capture the full tonality & range it is capable of. At 14-bit, a given range will have maximum tonality. At 12-bit the camera will retain the same range, but could have less tonality. All of these assume lossless compressed or uncompressed. Compression obviously changes many things when it comes to tonality & range.

When you move up from base ISO, for example 200, you are in essence clipping 1 stop out of the top. So you have the same tonality, but less range (a maximum half as much). In other words, you cannot expose as much. So by ISO 400, you have the same range & tonality at 12-bit and 14-bit for a given ADC.

This is true until you get to ISO 800--the second distinct ISO. Here, it will have more tonality than a simple software boost; but less than ISO 100, because again: the exposure range potential here is only 1/8th as much. Therefore, the practical tonality will be less than ISO 100 (if exposure at ISO100 is 8x as much). But again, because it is much less than the maximum tonality & range at ISO 100, 12-bit should likely be sufficient and indistinguishable from 14-bit here (and above) as well.

So 14-bit is really only practically different--and even then barely so--at ISO 100 & 200 on a Z6.

Noted and many thanks!

I was adding 1 + 2 and got 12! Ha. What are my 1 and 2?

1 - electronic ISO is via changing the signal amplification. High amplification leads to electronic noise (=noise in the image). I thought at base ISO, there is no or very little amplification.

2 - Because of no or little signal amplification, 14 bits then will give better data resolution, better image quality than 12 bits.

Guess my line of thought is irrational. Thanks for your clarification.

 plumberdp69's gear list:plumberdp69's gear list
Nikon Z6 II Nikon Z 24-200mm F4-6.3 VR
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