Re: Best CI for process, was RE: shadow density in zone III

Well, yeah. A DR of 3.0 would mean 10 stops of negative densitiy
(3.0/.3). Thus a normal 7 stop scene would thus be expanded to 10
stops, i.e. 10/7, or roughly a CI of 1.43. The highest CI I have been
able to achieve is about 1.1.-1.2 with modern films. OTOH, if you
deliberately go after high contrast scenes - say 10 stops or so, and
then develop to a CI of 1.0, then you would of course have a negative
DR of 3.0.... right?

On Sep 30, 2005, at 10:26 PM, Sandy King wrote:

> So let me ask again. What film/developer/agitation/temperature
> combination should one use for N development of in- camera
> negatives when the density range required for scenes of normal
> contrast is log 3.0 or above?
>
> And what should one do when the scene requires N+ development?
>
> My best estimate for most common films is that you can't get there
> from here.
>
>
>
> Sandy
>
>
>
>
>
>
>> Sandy wrote:
>>
>>
>>> In most cases we would like to have the ability to expose our film,
>>> develop it and print it so as to\ capture the full range of tonal
>>> ranges
>>> in the scene, from deepest shadows to highest highlight. What
>>> difference
>>> does it make if that is done with a negative that has a DR of 1.9
>>> or 3.5?
>>> Is there some visual superiority to a print made from a negative
>>> with a DR
>>> of 3.0 as opposed to one made with a negative with a DR of 2.0?
>>>
>>
>> I'm not Eric, but I'll put in my two cents worth anyway. As you
>> know, what
>> we're doing is mapping scene luminances to print densities through
>> two
>> nonlinear transforms. Although the same gross results can be
>> obtained over
>> wide variations in the two transforms, assuming that the
>> concatenation of
>> each transform pair is equivalent to each other transform pair, the
>> characteristics of the storage medium between the two transforms
>> -- in this
>> case, the negative -- will influence the results at a more subtle
>> level.
>> The fact that two transform pairs give the same *range* of print
>> densities
>> does not mean that the *actual* densities at equivalent (small)
>> points on
>> the two final prints will be the same, EVEN IF the overall curves are
>> identical.
>>
>> In my experience, better prints result from using high-contrast
>> negatives
>> and low-contrast printing processes (with the caveat that one
>> avoids the
>> most nonlinear regions at the toe and shoulder of each material,
>> except for
>> image areas where no detail is required in the print). I
>> speculate that
>> this is because one can get smoother tonality and better
>> separation of
>> values in one's negatives when the scene luminances are spread over a
>> negative DR of 3 than when they are spread over a DR of 1.5, and
>> smoother
>> tonality and better separation in the negative produces smoother
>> tonality
>> and better separation in the print. (Or, put the other way 'round,
>> smoothness of tonality and tonal separation that are lost in the
>> transform
>> from scene luminances to negative densities cannot be recovered in
>> the
>> printing process.)
>>
>> Of course, this assumes that smoothness of tonality and separation
>> of tones
>> are as good in low-contrast printing processes as in high-contrast
>> ones --
>> if it were inferior, one would need to trade off one deficiency
>> for the
>> other and choose the best compromise. In fact, the low-contrast
>> printing
>> processes seem to be better in this regard (even in the case of VC
>> S-G
>> papers), so there is an additional gain in the second transformation.
>>
>> Now, the question becomes where the point of diminishing returns
>> occurs --
>> how much smoothness and separation are required in a negative before
>> further improvement cannot be seen (or are not important) in the
>> final
>> print? For 16x20 (inch) prints from 35mm negatives, all of the
>> above is
>> critically important. For 11x14 contact prints from in-camera
>> negatives,
>> probably not so much. I can tell the difference in 4x5 negatives
>> enlarged
>> onto 8x10 S-G paper, but wouldn't call it earthshaking. In my
>> experience,
>> back when all we knew to increase the contrast of Pt was
>> dichromate, prints
>> from negatives suited to plain Pt were FAR superior to prints from
>> negatives that required contrast enhancement with dichromate to
>> yield the
>> same range of print densities.
>>
>> Best regards,
>>
>> etienne
>
Received on Fri Sep 30 21:34:25 2005