DEAR RICHARD,
I believe this is called "the intermittency effect" which, though caused by
mechanisms similar to those causing RLF (involving interstitial ions, free
electrons and latent image sites) is actually somewhat different creating
different effects.
I recall shooting jewelry catalogs in my NYC studio (hated still life but
needed the $$$) with 8X10 E6 film, even though I used two 2400 WS Speedotron
packs at full power, to get the depth of field I had to close up my 360 mm lens
to higher stops (ca. f32 and above). This necessitated multiple "pops" for each
exposure. There was a definite color shift from a single pop and there was a
very slight crossing of the curves though, luckily, not noticeable to either
the client nor the printer who printed the ads and catalogs. I seem to recall a
slight loss of contrast which was easily compensated for by a slight push in
the E-6 processing while slightly reducing the exposure by a slight increase in
f#.
CHEERS!
BOB
From: "Richard Lahrson" <gtripspud@xxxxxxxxx>
To: "pure-silver@xxxxxxxxxxxxx" <pure-silver@xxxxxxxxxxxxx>
Sent: Saturday, April 22, 2017 7:53:12 PM
Subject: [pure-silver] Still Life Strobe Question
In working in still subjects and strobe, would it be true
that four exposures say @ f/64 equals one exposure @ f/32
(strobe light only)?
When you run tests for the zone system, advice is sometimes
mentioned about cumulative exposures not quite being equal,
like not giving enough threshold exposure or something.
Any advice appreciated!
rich
