Submitted by PhotoMan on
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Help me understand Linear Raw curve option
e.g. when Nikon D5500 it reports only 4096 levels max when linear raw curve is on, when off it reports 16384 levels which one is correct?
https://www.upload.ee/files/17759355/Nikon_D5500.zip.html
Not very clear.
Linear Raw Curve: to use the linear tone curve instead of the nonlinear (compression) one. This
parameter is important only for cameras and data formats that use the tone curve specified in EXIF
data for raw data linearization (e.g., a significant number of Sony cameras).
There is no 'bit depth
Submitted by lexa on
There is no 'bit depth reporting' in RawDigger. Even if (embedded) Exiftool reports it: we cannot help you with the interpretation of this parameter.
Nikon lossy compressed images uses highlight compression (lossy) on RAW recording, expansion on decompressing (similar but not exact to Sony cRAW curve, please refer to this article: https://www.rawdigger.com/howtouse/sony-craw-arw2-posterization-detection see 'Inside Sony cRAW format' section).
How there is no bit depth
Submitted by PhotoMan on
How there is no bit depth reported if you show max levels per channel this not enough for indication of bit depth?
Yes, we display max data
Submitted by lexa on
Yes, we display max data level (of uncompressed data processed via tone curve if specified for format).
We never use 'bit depth' term.
We describe Sony lossy/cRAW/ARW format in depth in our article: https://www.rawdigger.com/howtouse/sony-craw-arw2-posterization-detection
Could you please count 'bit depth' of this format? Is it 7 bits (delta bit count)? Or 11 bits (base value for each compressed block)? Or 14+ (15?) bits (based on linearized data range, slightly above of 16384)?
Also what can you say about
Submitted by PhotoMan on
Also what can you say about sony's new "Lossless compressed RAW" available in a6700 is it really uncompressed?
Another question i noticed
Submitted by PhotoMan on
Another question i noticed that Nikon Z30 and Nikon Z-50 uses lossy compression however even when i enable Linear Raw Curve i see 16000 shades max that just a bug in RawDigger or its different compression than say Nickon D5600 which reports 4000 shades max per channel when Linear Raw Curve enabled?
Could you please point us to
Submitted by LibRaw on
Could you please point us to the page in RawDigger manual where we use the term 'bit depth'?
Perhaps there's no option to
Submitted by PhotoMan on
Perhaps there's no option to show bit depth but anyone who into photography knows that
8 bit = 256 shades
10 bit = 1024 shades
12 bit = 4096 shades
14 bit = 16384 shades
in RawDigger it shows number of max number of shades per each color channel so its pretty simple to convert e.g. 4096 shades to 12bit which essentially shows bitness of raw file.
So, if somewhere in the
Submitted by lexa on
So, if somewhere in the firmware we multiply the recorded value by 16 and instead of the range 0...4095 we get the range 0...65520, then our camera will change from 12-bit to 16-bit? Did I get the idea right?
Exactly if someone tempered
Submitted by PhotoMan on
Exactly if someone tempered with DNG like some apps that create stacked DNG then of course no way to tell the actual bit-rate as data was messed with, however usually with default apps in phone or camera its always showing correct number of levels and bit depth can be guessed successfully.
We try not to use the concept
Submitted by lexa on
We try not to use the concept of bit depth, since it is never known what kind of transformations were made in the camera.
Actually, your original question about Nikon is a question about manipulations/data processing inside the camera: the file contains only 4096 different pixel values, but linearized to 0...16383 data range via linearization curve. Is this 12 bit (counted by different pixel values) or 14 bit (calculated from data range)?
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