Thanks all for the corrections and new information regarding my
question whether Olympus originally intended the use of the 1.4x-A with
the 180/2.8 lens.
Hans van Veluwen wrote:
:That not what I wrote or intended. The page for the 1.4xA mentions
:compatibility with the 180/2, 250/2, 300/4.5, 350/2.8 and 400/6.3.
I am sorry that I misread your original post; seems that the 1985
edition of the lens handbook has gotten some corrections.
Gary Reese wrote:
:It might also have been an engineering/marketing see-saw over what
:was acceptable versus non-acceptable performance for the 1.4X-A
:combinations. ... So, while an engineer might say it wasn't a suitable
:combination, users were already accepting that level of performance or
:worse with generics.
This is certainly the case for the 1990+ agreement of all references to
use the 1.4x-A with both 180mm lenses.
Special thanks to Dave Bellamy for checking your references which
support some of my observations, but also correct quite a number of my
points. Specifically, my conclusion that the introduction of the 2xx,xxx
series of the 180/2.8 seemed unrelated to the intro of the 1.4x-A is
obviously wrong. The 2xx,xxx was thus introduced (at latest) in 1984,
and before the 180/2 which means that, if the converter engineers could
take care of the 180/2, they could do so for the new (???) 180/2.8.
Your guess that the re-numbering might have no relation to any design
changes might be right. Indeed, in nearly all cases Olympus hasn't
related drastic lens design changes with (big) jumps in lens numbering:
The X.ZUIKO to ZUIKO MC change (and the -in most cases- probably only
cosmetic change from ZUIKO MC to ZUIKO) occurred for most lenses without
any break in numbering. Even more drastic changes like the use of
radioactive vs. non-radioactive glasses in case of the 55/1.2 and 50/1.4
seems unrelated to a significant change in S/N. The 6/4 to 5/4
elements/groups change for the 85/2 (ca. 1978?) has -if at all- resulted
only in a small jump (110xxx --> 116xxx?). Only in case of the
35-105/3.5-4.5, the 1xx,xxx to 5xx,xxx probably relates to a clear
design change.
Interestingly, besides the 180/2.8 (113xxx-2000xx), also the numbers for
the 85/2 (127xxx to 2xxxxx) changed dramatically (and this was long
after the 6/4 to 5/4 transition), and this might have occurred at the
same time (1983/84). The late samples of both lenses (as many others)
have a "TNT" code at the back (which I like to interpret that they were
manufactured at the 1981 opened Tatsuno plant). Might be that the S/N
change just reflects some new manufacturing techniques (Tatsuno is
described to have invented highly automated production) and earlier
samples were produced somewhere else?
Konrad
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