Ström (strom_photo@usa.net)
Wed, 19 May 1999 22:02:28 -0400 (EDT)
In my portrait and figurative works I long ago discovered a disparity between
reflected sunlight and reflected strobe light in the film speed, i.e. the
density resulting from the same EV. I ignore this for the most part and use a
spot meter in both circumstances, with no change to the film speed rating,
which I long ago set for all B&W to half the ASA or 1 stop. So I rate 100 as
50, 400 as 200, 360 as 180, etc, and compensate during development. Because I
am using a medium format camera (Hasselblad) for all my work, I cannot
selectively zone develop. The resulting negatives are reliable, can be
printed on grade 2/3 fiber and no filter for variable contrast, for the most
part, with some modification generally required for more contrasty outdoor
negatives. Outdoor negatives are tricky for me because I photograph in very
difficult terrain. Visualization is less controllable with medium format roll
films because of the variability of sunlight from the time of measurement with
a spot meter to the taking moment (iconoclastic clouds) and the inability to
selectively develop. Skin is particularly notable for its red reflection and
tends to influence red biased film quickly to higher densities. I use a 25
red filter for some of my work and intentionally produce higher densities for
skin (most often in my studio), to produce a quite satisfying matte result.
The effect outdoors of course on flora is lower density negative because of
the green absorption.
My development is always the same:
20 degrees C., 10 minutes 30 seconds, JOBO, rotation 75, with TMAX developer
150 ml to make 1 litre (150:850). This is short 50 ml the recommended ratio
(200:800). The resulting negatives are generally quite workable, not overly
contrasty and within the realm of minor manipulation. I use a densitometer
(Photometer) to measure densities during printing (silver) and compensate for
excessive contrast range by increasing exposure according to the following:
measure the significant subject highlight areas (in my case the person); set
exposure time to 60-70% of the recommended exposure time given by the
photometer (which has been calibrated for a particular paper) for caucasian
and 100% of the recommended exposure for darker skins (with some subjective
consideration according to the individual). If the densist areas in the
negative exceed the exposure range of 3 zones greater than the subject, burn
those areas in this manner: during the initial negative evaluation, measure
them with the photometer; open the enlarger lens sufficient stops to equal the
recommended exposure time for the primary subject--remember this as the
burning factor; after exposing the paper for the time recommended for the
primary subject, open the enlarger aperture to the burning factor size;
selectively burn the dense areas for the same time given to the entire print.
Burning tool can be a sheet of developed B&W paper that is black on one side
and white on the other, with a small hole cut in either the center or toward
one end of the paper, depending on the use. This method has proved to be
effective in the majority of prints, providing a useful print the first time.
Ström
--- Judy Seigel <jseigel@panix.com> wrote:
>
>
> On Wed, 19 May 1999, John Erbes wrote:
> >
> > Gary,
> > It's my understanding that film speeds are slower
> indoors typically by a
> > stop or so as compared to their rated outdoor
> speed. I don't know why,
> > but I'm sure that someone on the list will
> explain.
> >
> > John Erbes
>
>
> I have tested this and found it true... assume it's
> the actinic quality of
> the light... probably more broad-spectrum outdoors,
> hits on more
> cylinders, so to speak.
>
> In addition, it's possible the light outdoors was
> more contrasty, which
> would give the up part a bit of a zetz -- don't
> remember whether Gary
> mentioned that or not...
>
> Judy
>
>
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