Re: Densitomiters


Judy Seigel (jseigel@panix.com)
Wed, 27 Oct 1999 12:59:49 -0400 (EDT)


> At 14:06 26-10-1999 -0400, you wrote:
> > I need to purchase a densitomiter for calibration of my Pt/Pd printing.
> >The problem I am having is most of the machines(Heiland,Mantis) that I see
> >advertised have very short throats. My format of choice is 12x20, and with
> >only about four inches of reach, I will not be able to read a large portion
> >of the neg. Does anyone know of a densitomiter that will work for this and
> >other "big" negs? Or is there a way to modify smaller machines to increase
> >their throat length?

Another comment on whether one really needs/wants a densitometer -- as
perpetrator of the two-white-cards method (who got it from G. Schmitz who
claims it "was around" somewhere), IMO, excellent as the card is for
*teaching* and classroom purposes, for serious personal use the
densitometer is indispensible -- *especially* for enlarging negatives.

I daresay if your neg is by view camera, develop once, and it's done, for
platinum printers whose process has just so many variables, you can set up
a workable chain without densitometering. But in my experience enlarging
small-format negatives, also film/developer testing, information from
densitometer is irreplaceable and essential. Also one helluvalot quicker.

Grab test strip out of the water, if you're feeling elegant put saran over
it, or blot, & get reading instantly. What is your time worth? But again,
this is a different type of information than the white card thing, which
is a comparison, not a figure. Although you can keep a chart of the
reading of each Stouffer step, that makes the process even more cumbersome
& vague for *everyday use.*

Someone said the eye can determine minute increments more accurately than
the instrument -- this is something of a spin on the info as I read it,
but anyway doesn't mean in the abstract or by memory of half stops --
means matching next to each other. (As I believe I've mentioned in print,
early densitometers worked by operator's matching tones by eye.)

One extreme fabulousity of the white cards in teaching -- I found -- is
the very concept. To students, just the idea of gradations to be tweaked
in a negative is revelation -- and often hard to explain/comprehend. The
demonstration with those two cards is the best way of breaking the news,
and once I began incorporating that into teaching enlarged negs, was
amazing how talented the class got. (Work from same level students taught
without that gizmo looks binary in comparison -- tones are *on* or *off.*)

But I repeat, for personal use of serious photographer, there's no
substitute for densitometer IMO -- *especially* if your target medium has
many variables.

Judy

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| World Journal of Post-Factory Photography > "HOW-TO and WHY"
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