Re: [Leica] 35 f1.4 Aspherical/ASPH/Ein Stuck

[Dan Cardish <dcardish@microtec.net>]

At 07:37 AM 20-02-98 -0800, Frank Filippone wrote:
>Bill... I need simplification....and a bit of help....
>
>The lenses on the Ein Stuck have 2 concave elements.  I have established
>that on 3 samples.
>
>I was not an LHSA member at the time of the VF article you noted.  I can
>not refer to any other characteristic of the lens than that I have noted to
>discriminate differences.  However, I assure you, the lenses noted use
>concave F+R elements.
>
>Everyone seems to want to say that these lenses were NOT the rare versions,
>but apparently there are only 2 versions of the 35 F1.4 aspheric lens...
>the
>Aspherical with 2 concave elements, and the ASPH with 1 concave element.

I am not sure why everyone seems to be getting all worked up over the
number of concave elements in these lenses.  Perhaps everyone is filtering
out my comments to the trash, but for those of you still reading:

I have issue 6.94E of Leica Fotographie International in front of me, where
on page 24 is a diagram of the newer ASPH lens.  I also have in front of me
a xerox of an article  taken from LeicaView, which announced the original
'aspherical' version and shows a similar cross-sectional diagram.  BOTH
diagrams look almost identical.  BOTH lenses have fron and rear elements
which dip into the lens (and thus are concave?, I forget the meaning of
convex, concave).   Again, why is this important?  My Minolta 100/2.8 macro
lens has a concave front element.  Big deal!

The older lens has an aspheric surface on the front of the third element
into the lens, counting the outermost, and another one on the rear of the
second element in from the back of the lens, counting the rear element.

The newer ASPH lens has only one aspherical surface, on the front of the
5th element in from the front of the lens.  

I repeat, from visually looking at the lens, the optics will look
identical, apart from the differences in the focusing ring machining and
the name spelled out on the front of the lens.  

The Ein Stuck lens is the newer 1 aspheric surface ASPH lens, not the older
2 aspheric surface 'aspherical' lens.

Can this be any clearer?

Dan C.