From: Sandy King (sanking@hubcap.clemson.edu)
Date: 03/25/01-03:44:00 AM Z
Sam Wang wrote:
>>Does anyone on the list have experience in making negatives for alternative
>>processes directly from slides? If so I would like to know how this works,
>>and in particular would be interested in a response to the following
>>questions.
>
>Yep. Many of my non-digital negatives for tricolor gum were made that
>way, with only some "in-camera" separations. I thought you knew that.
>Works well. Except the "difficulty" of using panchromatic films under
>the enlarger.
Yes, I remember that you worked from slides in making separations for gum,
and as you know, many of the color carbons and carbros I made some years
ago were made with separations of 5X7 chromes. However, I am primarily
interested here in going directly to a negative for monochrome work, and
how the quality of such a negative compares to the two-step
positive/negative method or with the reversal procedure. I can think
offhand of several clear advantages to the slide>negative route but perhaps
there are caveats to consider.
>
>>1. Does one determine the exposure for the slide material differently if
>>the final goal is to make negatives from the slides.
>
>Nope. Any well exposed slide will do.
OK, I have not exposed slide material in quite a number of years. Assuming
the use of an incident meter to measure the light, is it ok to use the
manufacturer's film rating, or should it be increased or decreased for our
purpose.
>
>>2. Assuming the use of a 6x9cm camera and enlarged negatives to no larger
>>than about 12X18", would there be any practical advnatage in either grain
>>or sharpness to the user of a slow speed slide material of ISO 50 over a
>>faster one of ISO 400.
>
>Yes. Slower films give finer grain and sharper detail. In some cases
>where the paper shrinkage between printings might prevent rendition
>of fine detail you may not notice the differences. However, with
>monochrome anything, especially carbon, you surely will see the
>difference.
>
So even with the combination above, which assumes only about a 6X
enlargment of the slide to go to 12X18" maximum, you believe there would be
a noticeable difference in the renditio of fine detail?
Sandy King
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