Best B&W Exposure Index and Contrast Index for Scanning

I've read that some people say they deliberately under-expose their B&W
negatives (without adjusting development time) and in doing so they gain one
or two stops of exposure. They claim the scanner is capable of doing a
better job than the enlarger on these (thin) negs. Whether this is true or
not, are there any "best practices" when shooting black and white with the
intentions of scanning? ie. reducing development time in the tanks? or is it
better to shoot with the recommended exposures and development times and let
the scanner do its job and make your sacrifices in PhotoShop?

Alan Smithee wrote:

> I've read that some people say they deliberately under-expose their B&W
> negatives (without adjusting development time) and in doing so they gain one
> or two stops of exposure. They claim the scanner is capable of doing a
> better job than the enlarger on these (thin) negs.

That sort of negates any advantages of using different grades of paper, or
filters. Anyway, with scanners, it really does depend upon which type of
scanner, and which model, followed by the experience of the scanner operator.

> Whether this is true or
> not, are there any "best practices" when shooting black and white with the
> intentions of scanning? ie. reducing development time in the tanks? or is it
> better to shoot with the recommended exposures and development times and let
> the scanner do its job and make your sacrifices in PhotoShop?

Find a method that gives you the easiest consistency with the scans, in other
words, the least amount of work. Also, the ideal is to get everything exact in
the scan, and not to "fix" it in PhotoShop. PhotoShop is destructive editing,
so it is best not to need to do many adjustments. You must also consider your
output needs, since offset printing will need different scans than newsprint,
or inkjet.

This may, or may not, help you, though here is what I do with most of my B/W
images. The majority of what I shoot goes through offset printing, though when
it comes to B/W, I often need to be able to have a few samples chemically
printed through the use of an enlarger and darkroom. The best compromise I have
found is to treat my B/W film like transparency film, and be very exact with
exposure. Then when scanning, mostly on a CCD film scanner, I scan as
transparencies.

Scanning B/W as transparencies gives you a reversed preview window, so what I
do is try to get a very even exposure, and match the preview closely to the
negative as viewed on a light table. Obviously, this might take some practice.
Once in PhotoShop (or similar software), the first step is to invert the image.
Then I look at the Channels, and decide which best matches my desired results.
This can sometimes be Red, and often Green. With a few images, sometimes a
combination of two Channels gives the best results. Once you have chosen one,
or two, channels, then discard the other. After that, convert to either RGB or
CMYK, depending upon printing output method.

Hope that helps, or at least points you in another direction. Definitely
experiment, and find a workflow that is consistent. Remember that there are
nearly always three ways to do anything in image editing, and I have only
pointed out one.

Ciao!

Gordon Moat
A G Studio
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