Archived posting to the Leica Users Group, 2000/02/22

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Subject: Re: [Leica] Always use a control
From: Christer Almqvist <christer@almqvist.net>
Date: Tue, 22 Feb 2000 11:40:08 +0100

Very true.  When I do tests, I always shoot a series of negatives at the
nearby subway station, at least  the lightning is always constant  down
there. I always stand on the same spot and alwas shoot in the same
direction. Very valid coomparisons can be made of  the negatives made in
that way.

I also shoot a series of grey cards illuminated by artifical light too, and
measure them with a densiometer, but that does not say anything about
sharpness and grain. I  have a standard natural light set up for testing,
both indoors and outdoors, but with natural light  the comparison is almost
impossible, the light varies too much. Two camera bodies is the only
solution to this problem that I have been able to think of. Has anybody got
a better idea?

>Speaking from long experience--I do edit the world's leading darkroom
>magazine, so, although not a leading expert myself, I do hang around
>with experts a lot--I would add that it's a very good idea to do a
>control whenever you are experimenting with any of the more arcane
>development techniques, such as water-bath, split or pseudo-split,
>modified formulas, forced physical development, post-fixation
>retreatment, Beutler formulas, et cet., et cet.
>
>Oftentimes, photographers experiment with some one-off technique and
>enthusiastically report successful results; but when doing the same
>experiment with a control they are somewhat less enthusiastic, since
>they often can't distinguish the specially treated negative from the
>control.
>
>--Mike