I did a little test between some 25 year-old
fiber (ektalure) and new, fresh RCIII. Shot
was on Tri-X 4x5, exposed & processed normally.
About 1/3 sec @ f32.
Enlarging lens is an Kodak 161mm.
Here's the differences:
Ektalure print scan
image used for comparison: http://members.iol21.com/dpconsult/Scan1.jpg
600 dpi scan, Ektalure: http://members.iol21.com/dpconsult/Scan2.jpg
RCIII : http://members.iol21.com/dpconsult/Scan3.jpg
Apart from the color difference in the paper, the RCIII shows a
better dynamic range in handling tones (contrast). The Ektalure
seems to get just a bit more detail, even though the distinction
of that detail may not be quite as good as the RCIII (because of
the contrast differences).
The difference shows up on the brush laying across the box. In the
center of it there is a dim spot. That's a piece of packing tape or
something similar. On Ektalure the edges seem to be a bit more distinct.
On RCIII the advantage shows in the distinct edge of the stool leg on
the right side.
On another area of the print, the stitching in their jeans is interesting
to observe. It's more distinct on the ektalure, but more noticable
on the RCIII.
Here's my conjecture on how one might describe the difference
RCIII would have more distince changes in tone,
represented the the straight vertical lines.
But because of the chemistry on the paper (molecule size)
it holds onto those tones over a greater area.
_______
| |
| |
| |
| |
----- ------
Ektalure would not have as great a difference between
the tones, represented by the slanted lines. But with
a smaller molecule the change would provide more detail.
__
/ \
/ \
| |
| |
----- ------
The difference seems similar to what happens with lens comparisons.
Contrast & resolution differences are often chosen at the discretion
of the user for the desired effect.
(I have no idea if this tought is accurate or just the rantings
of a lunatic. Maybe a chemist in the group can verify/refute
the thoughts. Willie?)
Collin
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