Paul Stenquist wrote:
(snip)
> And of course I'm using the same lower head with both the condensers and
the cold head,
(snip)
I would say, Paul, that you're still printing with a condensor system, but
you've exchanged the opal bulb for a cold-light head. To get a diffused
system you need to have the diffused light source, or a diffusion-box,
directly over the film-stage.
Also, you don't mention what film you were printing. Traditional b&w films
create the Callier effect when printed with condensed light (extremely so
with point-source light) which causes tonal distortion in the mid-tones.
This is because light is scattered by the silver grains and the paper
receives less exposure than a particular density of silver theoretically
should have transmitted. However the clear film doesn't cause any
appreciable scatter so practically all of the light reaching the negative is
passed to the paper from the clear shadows. The effect isn't as noticeable
in the highlights because that area is usually printed to the same density
as a matter of the individual operator's preference. Your mileage may vary
:-)
Chromogenic films (be they b&w or colour) have had the silver grains removed
by bleaching when processed, the image is a dye-image only so there is no
Callier effect. What this means is that chromogenic films will print with
the same characteristics whether a condensor or a diffusion enlarger is
used. Silver grained films, OTOH, will behave very differently according to
the illumination type of the enlarger. Unless you use the same type of film
you could be comparing apples with oranges!
Regards,
Anthony Farr
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