LaserSoft Imaging

Problems scanning prints with subtle tone variations

I have a problem when scanning prints (the same problem applies to negatives) which have a continuous gradient in brightness,
especially in areas which are close to “white”.
The problem can be seen on the attached picture. This a scan of a black and white print, which shows a continuous gradient from about the
center of picture to the left upper corner.
The scan was done on a Epson V750 using SilverFast AI.
The problem is that the scan shows an effect of “steps” from the lighter center to the darker corner. It creates patches of 4,5,6,7... percent of
grey, instead of mixing pixel values in between (like putting values of 5 % in the 4 % areas when turning towards 5 %).

Is this a problem of the scanner or the software. It feels like some part of the system is not able to capture subtle hues, instead combining
brightness values that are close to each other. Like jpeg compression..

The attached picture was scanned with 48 Bits, then converted in Photoshop to 8 Bit Greyscale and saved as jpg. Of course the initial scan in colour did noch show this effect as much, but it was still pretty visible. Converting made things of course worse, but I have seen
so many pictures on the web in jpeg/small file size that did not show this problem at all.

Could anybody give me some tip on how to achieve better results ?
Thank you in advance,

Christian

Dear Christian,

chrigel wrote:The problem is that the scan shows an effect of “steps” from the lighter center to the darker corner. It

I have checked your picture in three different monitors. I do not see any steps in the picture you have sent. Most likely the problem you are having is your monitor or your picture viewer which is incapable of showing you the gradients but in those "steps".
At this side the picture gradation is perfect.

Cheers