"Rob Novak" wrote in message
...
On 2 Mar 2006 06:01:38 -0800, "Dave the Guy"
wrote:

How is 135 acros compared to 120?

In what aspect?

They're both excellent performers. Acros in 35mm is
vastly superior
to Delta100 or TMX in resolution, grain, and tonality, at
least how I
process them (Acros in Perceptol, Delta and TMX in DD-X).
I love the
stuff. It and PanF+ in Ilfosol-S 1+14 are becoming my
go-to
combinations for tight grain and tonal response.
--
Rob on the Web - Trouble In Paradise
http://rob.rnovak.net

You are comparing apples with oranges. It is the
difference in the developer you are seeing, not differences
in the film. Perceptol or Kodak Microdol-X (virtually
identical) are extra-fine-grain developers. When used on a
film like those above the grain will be nearly as fine as
the late, lamented, Technical Pan in Technidol but with
considerably greater speed (EI 25 to 50) and much less
trouble with getting proper contrast.
Both T-Max and DDX are excellent for obtaining the
highest speed from a film but are grainier than D-76.
Perceptol and Microdol-X lose a little speed (less than a
stop) but deliver much finer grain.
In general, developers have little effect on film
resolution. Of course fine grain tends to allow higher
resolution, but the main factor is image spread caused by
"irradiation" or the diffusion of light in the emulsion.
Thin emulsion films, such as the Tabular grain ones, tend to
diffuse the image forming light less than older thick
emulsion or multiple coated films, so their resolution is
higher. Because the covering power of tabular grains is
greater than cubic grains the range of density of such film
is greater than the old thin emulsion films using
conventional grain types. So, one can have good tonal
rendition along with high resolution without short exposure
latitude or fussy development.


--
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Richard Knoppow
Los Angeles, CA, USA