[Leica] Re: How to read film data sheets

[Jim Brick <jimbrick@photoaccess.com>]

Many thanks Erwin. Without knowing the details, I came to this conclusion,
many years ago. It probably started in the early 60's when I first tried
Microdol-X and was disgusted with the results. After using various B&W
emulsions, various color emulsions, and various developer/film
combinations, it was immediately apparent to me that fine grain developers
produced fine grain but not the sharpest results. I started investigating
"high acutance" formula's. Found Rodinal, Windisch, and Beutler. And dye
cloud images (E4 back then) were never as sharp as "real" grain Kodachrome.
We all knew that Kodachrome was/is B&W emulsion(s).

My problem with Kodachrome, today, is that it has to be shipped
"somewhere?" to get processed. The West Coast Kodachrome lab used to be
right here in Palo Alto. After spending money traveling, buying a lot of
film, and make photographs that cannot be re-made, I refuse to pack-up my
film and ship it to a lab, 3000 miles away, who may elect to send it
somewhere else. Perhaps Canada. Kodak does this with Kodachrome! With E6, I
can process it, or have my very local Pro Lab process it. It is never more
than five miles away, expertly supervised (I know the supervisor), and is
un-touched by "common carrier (or uncommon carrier) delivery services",
UPS, FedEx, USPS, etc... You have no idea what conditions (temperature
extremes, rapidly fluctuating temperatures, etc...) your film will
encounter. This may change. Kodak is rolling out their Kodachrome
"mini-labs" and if one shows up near me, I will use it for some of my work.
But not all.

Alas... Kodachrome is only available in the 35mm format.

Jim

PS... I've been away for the past four days and I owe some of you responses
on private e-mail. I'll get to it, but please be patient...

many thanks,

Jim

At 11:28 PM 11/16/98 +0100, Erwin wrote:

>A comment has been made that Velvia is better than K'chrome because the
>resolution figure of V is higher than K (±160 versus ± 125). No doubt that
>the cited figure is put in the data sheets. Has it any relevance?
>No. I will as usual give a solid explanation why not.
>
>Why then is K for many purposes the better film: it is grain based where
>the V is dye cloud based. Recall that a dye cloud image is being generated
>by arificially restraining the growth of clumps of grain and replacing them
>by dye clouds of about the same dimension at about the same location. Note
>the vagueness here? A grain image is an exact replica of the optical image
>falling onto the emulsion. The dye cloud image is a chemical interpretation
>of this image.
>
>The capture of fine detail is better preserved with the grain based image
>and its 'hard' edges against the finer (smaller) dye cloud based image with
>the soft edges.
>
>This is same the reason why fine grain developers in fact kill fine detail
>and acutance developers enhance fine detail up to the limit of grain noise.
>Recall the Rodinal discussion?
>
>Erwin

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