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Re: 6D - sensor measurements and comparison with other Canon FF
In reply to Thierry Legault,
5 months ago
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Thierry Legault wrote:
rrccad wrote:
actually yes / no - the average black point is in the EXIF - however, the masked pixels contain the row / column offsets from the averaged black point. canon i believe if I recall correctly does not use the EXIF based row/column black point offsets but uses only the masked pixels.
your images look suspiciously like images that don't have that taken into account.
The banding crops are just here to give an idea of the intensity and shape of banding in comparison with other cameras. Balck point level is just an offset and in Iris, one can adjust the black and white levels at any values, to make the background darker or brighter as desired.
which is only the "average" black point value - not the actual row / column offset.
You know, in astronomy with CCD cameras we are used to deal with raw 16 bits files and offset frames and dark frames. And we are doing that since more than 20 years now, long time before the first consumer digital camera appeared
yes, however we also create bias offset black frames to automatically take into account row / column shifts in actual black point.
in theory the masked row / column values should remove any banding - the fact it's there is indicating it's not.
I think that Canon uses the masked photosites to decrease the banding level, but my tests show that to significantly decrease it furthermore, you would need hundreds of masked lines and columns, instead of a few dozens currently. This is clearly not the good solution.
they do.
canon has the entire right side of the sensor and the entire top of the sensor masked.
your banding values aren't accurate / real world because they aren't taking that into account.
as far as I recall, adobe will take into account the row data values.
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