filmscanners: VueScan and white pixel clipping SS4000

[Stan Schwartz <snsok@swbell.net>]

I am making a scan of an array of bright azaleas using VueScan and an
SS4000. I am scanning at 48-bits.

I am not sure I understand the settings correctly in VueScan. My scanned
images are showing a lot of burned out highlights. The Photoshop histogram
shows a lot of bright pixel clipping off the the right side of the
histogram, confirmed by Option_clicking the white triangle.

I tried scanning in both white balance and autolevels. The Help information
says that I would be best with autolevels for this type image.

Looking at other high brightness images, it appears I am getting a
significant amount of clipping if I leave the white point setting at 0.5%.
Even at white point set to 0.0%, there is a small amount of white pixel
clipping.

I am not clear what is accomplished by having the white point setting
defaulted to 0.5%.

One other thing the histogram shows: across the top of the histogram, even
before I make any level adjustment, I am seeing about a dozen or so
"whiskers". I understand why these show up after levels adjustments, but I
am not clear why I am seeing them on the unadjust image.

This clipping and the "whiskers" are not showing up when I scan with
Polaroid's software.




Stan Schwartz

www.tallgrassimages.com