Digital BW, The Print

Hi Shilesh,

Thanks for your response.

> Kevin,
>
> You are absolutely right - but only for conditions you tested, i.e.,
> (1) the scene density range can be fully caputured on your film, and
> (2) the density range captured on film is within the capability of
> the scanner to render.

Yes that is true.  Mostly.
(1) If the scene brightness can't be captured on the film (like EV 500 
or something silly like that) then there is nothing you can do about it 
including adjusting development times.
(2) yes, definitely the density range of the film must be within your 
scanner's specs for this to work. The principle still applies.

>
> The need push (N+) to make a flat scene (low density range) more
> vibrant (more density range) is probably obsolete when you scan the
> film.  However, if your scene has a density range greater than the
> film is capable of capturing (N), than the range can never be
> regained in the scanning stage.  The same is true if the density
> range already captured on film is greater than the scanner is capable
> of rendering.  The latter probably does not apply to negative film
> which does not render dynamic range as high as color transparency
> film.  But for the former, the only way out of the mess would be a
> pull (N-) exposure.

As I've said this will not work in extreme cases.  I'll go out on a 
limb and suggest that this will work in the range of N-2 to N+2.  
Although my case for supporting N+2 is anecdotal.

>
> Regards.
>
> Shilesh
>
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, Kevin Gulstene
> <kevin@d...> wrote:
>> Traditional compensating development techniques for negatives are
> not
>> required to produce a good print when the negative is going to be
>> scanned and not printed traditionally.  It is, in most
> circumstances,
>> not material to the success of the print whether you use 'normal'
> or
>> compensated development (N+ or N-).
>>
>> How's that for an iconoclastic statement!
>>
>> My premise was that as long as the negative was exposed correctly
> for
>> the shadows (ie the density range of the negative was up off the
> toe)
>> it would not matter whether you developed it for a 'normal time' or
> N-
>> time or N+ time.
>>
>> This makes sense to me because of how I believe the scanner and
>> software work.  When you scan a negative and apply set points you
> are
>> mapping a density range on the film to a set of numbers (say
> between 0
>> and 16383 for a 14 bit scanner), and then mapping those numbers to
> a
>> grey scale.  For example if the negative's optical density range is
>> from .4 to 1.8 then if no data is clipped by set-points then the
>> density of .4 produces a 100% black in the file and the density of
> 1.8
>> produces a 0% black in the file.  If that same negative had been
>> developed differently ( say N- ignoring the 1/3 stop more exposure)
> and
>> its density range was .3 to 1.5 it would produce the same file.  .3
>> gets mapped to 100% and 1.5 gets mapped to 0%.  So the scene
> brightness
>> that produced the shadow density value of .3 or .4 produces the
> 100%
>> black in the both cases  and the scene brightness that produced the
>> highlight densities of 1.5 or 1.8 produces 0% black in both cases.
> The
>> absolute value of the densities produced by the development doesn't
>> make any difference except perhaps in extreme cases with very high
>> (3.3) or very low (.5) maximum densities.
>>
>> I made a simple test yesterday that seems, to me, to validate that
>> premise. Here was the set-up: I exposed took two rolls of film with
>> each frame containing the same image.  I used the new plusx.  The
> first
>> roll was at my 'normal' EI 64 ( exposed 1/60s @ 5.6) developed in
> D76
>> 1:1 for 7:15.  The second roll was exposed at EI 40 (exposed 1/60s
> @
>> f4) and developed for 5:00 D76 1:1.
>>
>> As you would expect the 'normal' negative was much denser in the
>> highlights.  I scanned one frame from each film strip on a
> sprintscan
>> 120 using vuescan.  The little density meter in vuescan (for
> whatever
>> it is worth) gave a density range of ~.35 to ~1.85 for the 'normal'
>> negative  and ~.4 to ~1.5 for the N- negative.  I set vuescan to
> scan
>> B&W, 16 bit, Neutral color balance, with black and white points set
> to
>> 0%.
>>
>> The two raw scans are  different as you would expect.  The N-
> histogram
>> is offset a little further from the left  and was shorter in length
>> than the 'normal'.  The set pointed scans were virtually identical-
> !!
>> I made a levels adjustment to each image to bring the white point
> in to
>> clip of the specular highlights in each image and the two images
> are
>> pretty much indistinguishable.  Their histogram data is:
>>
>>                     Normal            N-
>>
>> Mean             178             182
>> Std Dev           52               51.9
>> Median           198             204
>>
>> My new zone mantra is: expose for the shadows and let the
> highlights
>> fall wherever they want.
>>
>> It is arguable that a more dense negative is better because the
> scanner
>> will extract more data into the raw scan file but that does not
> seem to
>> make any practical difference.  Perhaps it would if you were to
> apply
>> aggressive curves.
>
>
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