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, if I could jump in here, I've never seen any particular
correlation between how the print looks after exposure (whether you
can see an image in the undeveloped print) and the quality or
tonality of the developed print, and I used to puzzle about that
quite a lot, years ago, why sometimes I could and sometimes I
couldn't see an image after exposure, and how little difference a
visible image after exposure seemed to make as far as the final
product. I'm tempted to speculate that a more contrasty negative,
like Loris's and like the ones I used in those early years (laser
printer negatives) would be more likely to produce a visible image
after exposure, but since that's the only kind of negative I ever
used in those days and I didn't always get a visible image after
exposure, that couldn't be a sufficient explanation. The negatives
I use now are very thin and after exposure there's never any evident
image at all, but they print a full tonal range. I'd need to see
the print after development; in my experience the print before
development doesn't tell me anything useful at all. Just my 2cents,

On Oct 17, 2008, at 1:55 PM, Keith Gerling wrote:

I am going to look more carefully at my next print, but off-hand I
would say that I can see very little highlight detail in my prints
before development.  I've had occasions where I could barely detect
any image at all, but have still come up with a full-toned print after
development.  How long did it take to develop that print?

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

Color is accurate (not 100% perfect but very close).

1) Could browner mean more exposure? If so, then that means your
get much more exposure than mines, which is something relatively
comparable (because of same negative media - and mines are non
oiled, to
remind), plus, since your highlights don't cook (presumably), that
mean your blacks in the negative are way denser than mines... This
is how
I interpret. What do you think?

2) I don't understand this, which parts of the image are invisible
in yours?


17 Ekim 2008, Cuma, 11:07 pm tarihinde, Keith Gerling yazmış:

Yes. If that color is accurate, I would say that my
exposed-non-developed prints are, 1) browner than this, and 2)
not as
much detail can be observed on mine. Very interesting. You've
got the
entire image visible in an un-developed picture.

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

BTW, see the just exposed yellow layer of the same image (on


Anything unusual to your eyes?