U of S | Mailing List Archive | alt-photo-process-l | Re: Gum calibration (was: Paper negatives- Ink Selection)

Re: Gum calibration (was: Paper negatives- Ink Selection)

Keith, I've said this before, but since it keeps coming up I'll say
it one more time: if your goal is to reduce exposure times, this
isn't the most fruitful place to look IMO.

Mark has pointed out that exposure time isn't a function of printer,
ink type, ink color or printer settings:

ender100 wrote:
> Exposure time does not depend on the printer, ink or color of the
> negative—it merely depends on the substrate you are printing
> on—providing all other variables are equal.

and logic says that exposure time can't be a function of curves,
since the exposure time is established before the curve is
calibrated, and doesn't change after the curve is calibrated.
Exposure time is a function of a lot of things such as light source,
dichromate concentration, pigment concentration, paper speed,
environmental conditions; how the negative is generated is not a
significant factor, in my experience.


On Oct 17, 2008, at 12:00 PM, Keith Gerling wrote:

It helps.  The negatives are pretty dense.  When you started to talk
about negative density I was getting concerned.  The only Pictorico
negatives I've actually held in my hand were some made by Sandy King
and I was astonished that he was able to get such a range of tones
from something that looked so "thin".  Your paper negs don't look any
different from mine.

2008/10/17 Loris Medici <mail@loris.medici.name>:

17 Ekim 2008, Cuma, 5:50 pm tarihinde, Keith Gerling yazmış:


I'd be very interested in seeing
a snapshot of one of your un-oiled negs, if that would be possible.
Just something that give me an idea of your range of tones.

See here:

1. http://tinyurl.com/68txaw
(full 400dpi scan downsized to screen resolution)

2. http://tinyurl.com/698az2
(100% crop of the 400dpi scan)

Hope that helps somehow...