Bob Michaels
nobody special
Bob, I find this very interesting, could you please elaborate?
I use the SilverFast software that came with my scanner (Plustek 7600i) and try to control contrast and colour and crop during the scanning -- I just never got the idea to scan 'raw' and adjust later.
What are the advantages of your method?
What image manipulation program do you use?
Thanks!
OK. First it is important to understand what the scanner does (and does not do) and what the scanner software does. The scanner shines a light through your neg or positive and reads the detailed shadow on a sensor. That is all. It then passes this data back to the CPU. Note: it does not know or care if it is a neg or a slide, RGB or monochrome, or even how it is cropped. high rez or low rez, It sends this unmanipulated data back to the scanner software in the CPU.
Then the scanner software can adjust the cropping, make it a positive or negative image, convert the RGB data to monochrome if desired, downsize the file if needed to be lower rez, and output that file as either 8 bit or 16 bit.
But, the scanner software can do, and often automatically, does more. It can crop it to what it thinks is the edge of the actual image. It can apply standard "this usually works" adjustments to your file. It can set the endpoints of the the histogram (levels). It can adjust the contrast. It can tweak the color balance. It can sharpen the file. Sometimes you do not even know the scanner software is doing this because you cannot turn it off. Hence my analogy to a JPG coming out of a digital camera. This is good for those who want a quick acceptable file with no additional processing in an image editor. And, this is great for those people who evaluate scanner software by how good the initial output looks.
Other scanner software (Vuescan) acknowledges that you may be better at doing all those adjustments manually. So it allows you to turn everything off that you don't want. This is good for those people who know that once data is clipped off the end of a histogram, it cannot never be recovered. This is good for those who know that any adjustment like color balance or contrast to counteract a previous adjustment never gets you back to the quality file you started with.
Vuescan does have many manual adjustments. These are for those folks who do not use image editors but want something better than the auto adjustments. Few people use these Vuescan manual adjustments because they know they cannot see the real impact, cannot control them very well, and cannot undo them since they are included in the outputted file. Instead they do all those adjustments themselves in their image editor.
I have been using Vuescan and Photoshop for about 10 years now. No intention of changing anything.