Gregg wrote:
"Can you explain the process?"
Sure. Paper flashing is a technique used to expose the paper to
light in such a way that it is kept just short of visible
fogging. The trick is to get it as close as possible without
actually passing over the threshold. Then you expose the
negative on the paper. A highlight that is heavily blocked up
won't normally show any density on the print, but with the
additional exposure from the flashing you may get some detail.
However, if the highlight is a solid Dmax on the negative, it is
probably toast and you'll just get a dingy white. If the tonal
details are buried in the shoulder, you have a fighting chance
of recovering them. Advanced darkroom technicians may vary how
close to the threshold they get depending on the negative. They
may also exceed the threshold and then use a fog clearing agent
in the developer. Lot's of deep, dark secrets there.
Split-Grade printing is a relatively recent discovery in the
world of photography. Multigrade/Variable Contrast papers have
two emulsion layer that are sensitive to different colors of
light and have totally different response curves. Well, one
layer is your Grade 00 emulsion and the other is a Grade 5
emulsion. As you vary the color of the light passing down from
the negative to the film you skew the sensitivity from one layer
to the other. That's how these variable contrast papers work.
Some darkroom techies with way too many braincells lurking
around created a new printing technique. Why not expose the two
emulsion layers seperately? WOW! Here, in a nutshell is how
it's used:
1. Exposure one is your Grade 00 exposure. This essentially
prints everything from Zone IV to Zone XII. Mids and highs are
what you are printing.
2. Exposure two is your Grade 5 exposure. This prints
everything from Zones 0-III. (when printing most negs at grade
five, essentially everything from Zones VI on up disappear, so
there is very little overlap)
So you have a problem negative that needs to be printed Grade
3.5 to get the shadow details right, but then your highlight
blow away? Use split-grade printing. With the first exposure,
get your high values right. Then with the second exposure you
are essentially filling in the low values. Eke your times up
and down a little to get the ratio you like. This is very much
a subjective thing. There is no magic setting and no two
negatives will work the same.
Some people have written that you reverse the two exposures for
hard vs soft negs, but there really is no difference. I've
completely standardized on just one technique--mostly because of
my timer, and also because I confuse easily in the dark. Stick
with just one sequence and don't worry about it.
In "Photoshop" and other image editing software, you have gamma
control. These techniques are the equivelent to gamma control in
the darkroom. With Split-grade printing you really have more
control over the bottom end of the tonal scale and
paper-flashing gives you more control over the top end of the
tonal scale.
Neither technique are cure-alls, nor would you use them on
anything you don't have to. They are tools to be used when
needed. Split-grade doesn't work well on grainy negs, but is
perfect for C41 "dye-cloud" films.
AG-Schnozz
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