histogram offset

[drm]

hello,

can anybody help me understand why an image's histogram in Silverfast preview does not match the scanned image in Photoshop ? It seems compressed in Photoshop (black point shifted a long way left, white point shifted right).

I cannot find any setting in Silverfast which would appear to carry out such compression....

thanks for any advice

David Mantripp

[degrub]

assuming black pt is on the left .......i think that what you are describing would be expansion to fill the range. Take a look at the histogram in SF and look for the mapping bars for input and output. If the IN (top) is smaller than the OUT (bottom) then it would be expanding to fill the dynamic range.

THe histogram will change some between preview and final scan, particularly if a low resolution prescan is used.

Frank

[drm]

Frank, thanks for your answer - you are correct. It all became much clearer with Ai Studio, where you can see the output histogram simultaneously. Sorry for such a belated answer!