Originally Posted by
rdenney
The problem with using narrower color space, though, is that it will clip the ends of the histogram. This may be a "feature" of Vuescan, but I always clipped the histogram when using a narrow colorspace output, and have largely solved that problem by using ProPhoto. I've never had banding issues with my Nikon 8000 using a wide space like ProPhoto, unless I'm doing something really extreme with a curve adjustment. I did get clipping when I used sRGB, which is worse.
The Raw space in Vuescan is Raw only from Vuescan's point of view, not from the scanner's point of view, near as I can tell. I always scan to a wide colorspace and store in a 48-bit TIFF file, rather than depending on a post-scan raw conversion. So far, I've not lost anything by doing so, that I can tell. I then open the TIFF file with Photoshop and make general corrections and most interpretations in the wide space. If I need specific (and narrower) downstream colorspace (such as for web display), I convert (NOT assign) to that colorspace as part of targeting the image to that output. (I keep correction--which applies to a standard file--and targeting as separate processes.) The only time I get banding is from noise in dense areas, and then only when I'm trying to move those tonal values far from their starting points.
The only time multiscanning does any good for me is in those cases, when there is a lot of density in the slide or negative. Multiscanning averages several samples from those parts of the image where the sensor is starved for photons and therefore subject to noise. For images that are mostly bright, or where I'm not trying to bring shadows up a lot, I don't notice much improvement. (Or for negatives that are mostly dense with highlights where I might be trying to pull them down a lot, particularly bright skies.) One way to avoid the the temptation to really move those values is to get the filtration close in the camera. The less I have to move those tonal values in Photoshop, the better the outcomes for me.
Rick "whose experience may not be universal" Denney
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