Liam Lawless (lawless@vignette.freeserve.co.uk)
Tue, 09 Mar 1999 19:47:30 +0000
Hi Judy,
The intermittency effect is something I (and probably you too) have often
seen: if you do a test strip covering, say, 10 to 20 seconds in 1-second
increments and decide that 18 seconds is the one, you will normally find
that a straight 18-second exposure gives a darker result than your
10-second+8X1-second strip, especially on SG paper. At least, I do. I have
not looked too closely at the difference, but, since I have not noticed it,
I imagine that any
contrast difference would be fairly negligible. Next time I print, I'll
test.
Glycin, unfortunately, is too expensive for me. Hopefully, however, we'll
be getting deeper into development at a later date, which, in view of what
Kevin says, is probably the best way to go.
Liam
-----Original Message-----
From: Judy Seigel <jseigel@panix.com>
To: alt-photo-process-l@sask.usask.ca <alt-photo-process-l@sask.usask.ca>
Cc: Alt Photo <alt-photo-process-l@usask.ca>
Date: 09 March 1999 05:32
Subject: Re: Reciprocity and contrast control???
>
>On Tue, 9 Mar 1999, Liam Lawless wrote:
>
>Reciprocity failure....
>
>> Film data sheets, as far as I remember, give it
>as a function of time only,
>> but maybe that's just to keep things simple. Does the relation of tones
to
>> each other change as reciprocity occurs, or does everything just get
>> lighter? Any info will be welcome, particularly if it's what I want to
>> hear! (But it also has to be true!)
>
>True, you want true ! Nothing is true, this is the age of relativity. But
>your question reminds me of reading about the something Effects, and there
>were a bunch, like intermittency effect. You make brief exposures at
>various intervals, changes density (tho contrast I don't recall). I tried
>that, BTW, no effect -- on the film I was using.
>
>I also tried latensification. Did NOT work on lith. Fogging on lith film
>nada, too -- I mean it fogged, but didn't change contrast in pos to neg.
>
>Didn't think of long, low exposure, suspect my equipment wasn't tightly
>enough controlled -- no voltage meter. But one thing I did find REALLY
>changed contrast (is that what we're talking about Liam?) was the glycin
>developer. Old, brown glycin in one day's tests was amazing. Never got
>back to it, though, and maybe Dave could prove it was a chimera...
>
>cheers,
>
>Judy
>
>
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