Digital BW, The Print

Kevin,

> It seems to me that as long as the maximum film density is within the
> specs of your scanner it doesn't matter whether you used N or N-4
> development.

I believe, you get better tonal separation from + development, as that
increases the image density on the film, therefore giving more overall
discernable (by the scanner) tones.  The trick is to fit your image scene
density into that.

In other words, given how our scanners work, when you scan something with an
overall density range of 1.6, you get, say, 100 different valid image data
values.  When you scan something with an overall density range of 2.3,
you'll get, say, 200 different valid image data values.  That's just how
these fixed gain scanners work.  So, if you can spread the tones out over a
higher density range, no matter what the scene density actually is...I think
you have the most information to scan.

Now, to your question.  I believe if you don't compensate develop, you
either short the expansion of the tonal range, therefore, similar to above,
you would get lower density and therefore less tonal separation...or clip
the compression of the tonal range.

> You have to make the scene brightness fit between black
> and white one way or another.  You can do it with development or math
> in the scanner.  The result, it seems to me is the same.

Not if you lose image information via not doing compensation development, or
because you don't have enough data separation.

> Clearly you have to set a film speed appropriately to capture the
> shadow details but I am not convinced that modifying the film
> development is required to capture the highlights when you are scanning
> a negative.
>
> That is what I am trying to come to grips with.

I understand what you are saying.  Let me think about it.  I believe that
since the development "brings in" the highlights, without doing so, you
would lose them.

But, the conclusion I'd draw from all of this, is that you would get "more"
scanning data from higher density range...so use a film that provides the
highest density range, and develop for a higher density range...but longer
development times bring out grain, so there are, of course, trade-offs.  The
other issue is you really only need at most 200 different tones in a B&W
scene...more than that, the eye can't discern...and printing techniques,
like Piezo, claim to "fill in" to "smooth the transitions" between visible
tones, so they claim to print far more tones than you actually give data.

Interesting discussion, thanks!

Austin