[Leica] Apo definitions

[Mike Johnston <michaeljohnston@ameritech.net>]

>>>Mike wrote in part that there two definitions of "apochromatic" and
cites Sidney Ray (Applied photographic Optics) as the source.There is
a danger when citing from one source if one is not well acquainted in
the relevant disciplines, that misunderstanding will be the result.
The one person who has studied the apochromatic corrections fully is
Ernst Abbe, and in his writings you find three different descriptions
of the apochromatic correction:
correction of the secondary spectrum... <snip><<<


Erwin,
Yeah, "wrote" in response to your "innocent" request, which of course
was a set-up for a sucker-punch. Thanks, pal.

Interestingly, you begin the above post by excoriating me for citing
only one source (Sidney Ray, whose book is the universally acknowledged
standard text on the subject--is there one other book that more
completely meets that description?), and then you proceed to...cite only
one source.

And who's that? Abbe, who died in 1905. (Lurkers: that's NINETEEN
OH-FIVE.) Now I get to go scurrying off after some annotated proof so I
can point out the self-evident error in the claim that a guy who died in
1905 is hardly "the one person who has studied the apochromatic
corrections fully"? Not my cuppa. Can I just leave it to lurkers to draw
their own conclusions, please?

And even if he was, what in the hell has that got to do with the way the
term "Apo" is understood and used in the present-day camera industry?

Your conclusion that there is not a "looser and stricter definition" of
apochromaticism contradicts Leica itself, at least if Laney is to be
believed (second edition, pp. 13-16.) You probably think he's full of
crap too. I won't even bother recounting the conversation I had with an
employee of Leica during which it was explained to me at great length
why a Leica lens called "Apo" was very different from a cheap consumer
zoom with the same designation, namely, because Leica were "very strict"
about their standards for what they would call Apo. I'm sure this will
be an insufficient citation for you unless we can call the fellow, wake
him from his sleep, and get him to repeat everything into a
tape-recorder. Forget I mentioned it.


>>>The only person who ever conducted a large scale scientific
research project on all aspects of B&W processing is Richard Henry in
his book:"Controls in Black and White Photography". <<<

Dr. Henry, with whom I corresponded in the years before his death, would
have been the very first to demur with this altogether outlandish
statement (Haist? Mees? Davis? Zawadzki?). He and I found we had a lot
of common ground, and his book is one of my favorites (I included it in
my four-part article for _Camera & Darkroom_ in the '80s, "A Basic
Library of Photographic Books," "Part IV: Technical Books," so although
you've never seen any references to it, I've referenced it myself, many
times in fact, and seen it referenced many times). I have two copies of
the second edition in my library. I learned a lot from him and agree
with many of his conclusions. But Dick was essentially a hobbyist,
occupying himself for fun in his retirement. His research, which was
carried out in his BASEMENT, for God's sake, was not "large scale." It
was decidedly small-scale. He's not among the top ten all-time
researchers of "all aspects of B&W processing," not by a long shot, not
by any measure, not by whatever stretch...and he himself would never
have claimed to be.

Point nth, what in the world would you hope to prove by "testing" some
old Nikkor lenses NOW? The phenomenon we've described falls under the
heading of social history. If there was a "sensation" among
photographers in the 1950s, then there was. It's not something that can
be discounted by arguing the merits of common assumptions years and
years after the fact on points of debate.

But if you're just trying to wear me down here, you're succeeding. I'm
getting tired of your hostility and argumentiveness. It reminds me too
much of what I do for a living.

- --Mike