Panasonic Lumix G 20mm F1.7 II (H-H020A) - Banding

Started Aug 6, 2013 | Discussions thread
Anders W Forum Pro • Posts: 21,468
Re: It is in my world

tsi wrote:

Anders W wrote:

Banding aside, I am a bit surprised that the RAW converters do not have better tools for dealing with the problem of tint changes in the shadows due to black-level clipping. This is a problem that it should be possible to attack with some specific, at least partly automatized tool.

Hope to see this in LR6. Are you sure that none of the other raw converters has a solution for this?

No, I am not sure. But I doubt it. Of course, some other RAW converters may well have special sliders for WB in the shadows. If I recall correctly, Silkypix (for example) does and these sliders (temp and tint, IIRC) may be slightly preferable to the single one offered by LR (tint only). But this is not really what I am thinking about. What I'd like to see is something that eliminates or reduces the original problem in an automatized and continuous fashion, i.e., prevents the artificial "boosting" of the signal when we get close to the black-point, which is due to the fact that the negative side of the noise distribution is clipped at the black level (represented by zero).

Conceivably, something like that might be accomplished by a special NR scheme that compensates for the clipping of negative errors by pulling back the values of similarly dark and neighboring pixels a corresponding amount toward zero. The average signal would then remain what it should be rather than become systematically more positively biased the more the true signal approaches zero.

Of course, such a scheme would probably require that the data on negative errors are present in the RAW file as I think they are on most MFT cameras. However, at least some Panasonic cameras have black-level clipping implemented already in the camera hardware. I know this to be true about the GH2 and would guess that all Pany bodies before the GH2 are the same. I am not sure the GH2 is the last Pany example but I do know that the G5 and the GH3 are different in this regard.

 Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Olympus E-M1 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH +28 more
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