Yes, I had forgotten the term. I think intermittency and
reciprocity are related, in any case several exposures do not always add
up to a single longer one.
On 4/23/2017 4:56 AM, bobkiss caribsurf.com wrote:
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
