From: Richard Sullivan FRPS (richsul@earthlink.net)
Date: 06/19/01-03:30:46 PM Z
Mirrored surfaces are not as reflective as a flat white surface as strange
as it seems. Mirrored surfaces, if they are not flat, can create specular
reflections that can obviously create problems.
The issue of diffused light versus point source light in enlarging is a
well known phenomenon in photography. The principle applies to contact
printing as well. The perceptual difference will in fact depend to a large
degree on the nature of the images being printed. In theory a contact 8x10
print is less sharp than a 8x10 neg enlarged to an 8x10 print. This is
statement sure to start a fight at the next alt gathering!
Dr. Henry in his famous book on B&W printing, whose full name and book
title escapes me at the present, poo poo'd the idea of diffused enlarging
printing saying it is just softer in contrast. A.A. disagreed. Some
printers swear by diffused enlarging and others swear by point source. The
same is true of contact printing.
We had a discussion about this when Stephen Livick taught his on-line gum
classes at my site and several printers at his beckoning switched to metal
halide. Some posted samples and sent me some from the same neg printed
under the FL and MH systems. There is a decided difference. Whether or not
these differences can be perceived by the average printer or viewer or not
is a question. Some difference I suspect depends again on the nature of the
image. A broad poster like gum print may show no difference whereas a print
made in a finer mode like Livick makes might show a difference. I think the
advanced printer will see the differences in many processes and then it is
a decision as to which is preferred. Since film and emulsion thicknesses
are part of the phenomenon, colloid and thick emulsion images are to be
considered.
I use both FL and MH systems. The FL I use mostly for demos on the road
etc. Platinum shows less of a difference though I swear I can see a
difference in that the MH prints seem to have more depth and life but it
could be my imagination. We tested POP paper under both and there is a
definite difference there which I think is due to the emulsion depth on the
paper.
I know some may find this a bit complex in terms of theory etc, but the
analogy I have used for many years when discussing printing techniques with
new printers is that it is like climbing Mt Everest: it's the last 1000
yards that the killer. The difference between a good print and a
spectacular print is 1%. Some of us will be forever slicing and dicing that
last 1%. It can become an obsession. Then of course we can just dump the
last 1%, be happy with good prints, and go make more pictures. Depends on
whether you are an image maker or a print maker -- I guess.
--Dick Sullivan
At 04:17 PM 6/19/2001 -0400, you wrote:
> >However I would suggest it not be a
> >reflective surface as mention by Kerik
> >unless it is painted flat white.
> >A mirror type reflective surface
>
>Painting it flat white is not necessary, although you can do it if you
>like the smell of spray paint. Neither galvanized sheet metal nor
>(non-polished) aluminum are mirror-like surfaces. Plus the tubes are
>generally placed very close together so any reflections are overwhelmed by
>the primary light source itself. I print pt/pd often with very high key
>images that would easily pick up any significant irregularities in the
>light source. It's NEVER been a problem.
>
>Experience over speculation.
>Kerik
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