RE: "dry plate" negatives

["F. Wentzel" <fotochemiker@yahoo.de>]

Some Dry Plate notes:

ken watson wrote:
1.
"My directions caution that this washing does dilute
the emulsion..."

Water washing is cheap, safe and works just fine.
Furthermore, it avoids some problems other methods
cause which can degrade the image.(Dilution CAN be a
problem in certain circumstances, but it can be
avoided and is usally not a problem, when proper care
and methods are used.

2.
"I think most / all start out orthochromatic..."

No, silver halide emulsions start out as "ordinary".
(ie. uv/blue sensitive)

3.
"...and one then needs to add VERY EXPENSIVE dyes in
very small amounts to make it panchromatic..."

Well, yes, to increase the emulsion's sensitivty to
blue and green (orthochromatic) or blue, green and red
(panchromatic) one may use dyes... some of which
are... very expensive.

Fritz

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