[Leica] some comments

[Erwin Puts <imxputs@knoware.nl>]

SP wrote:
<I bought a used, mint Noctilux last week, latest 1.0 version, and ran a
<roll of Koday Royal Gold 400 through it this week The subject was 3 feet
<from me and all of the pictures of same were blurry. If this was not due
<to incorrect focusing in the M6 viewfinder, was this because I am
<unaware of the true minimum focusing distance at f 1.0? IOW, what is the
<true minimum and maximum depth of field allowance at f 1.0? Thanks!

As I noted in my Noct report (Phototechniques) the Noct at 3feet (its
minimum distance and full aperture) is not at its best. At this distance
the DOF is 2cm at most. It is possible to get clear and sharply outlined
pictures however. But you must take care. Do not expect at full aperture at
this distance the kind of quality you easily get with a Summicron-M at
f/2,0 and 1 meter. You will be disappointed for ever. The Noct is a
thoroughbred lens and as a non-GP lens it has its limitations and strong
points.



Don wrote:
>You have received some excellent feedback on the properties of the
>50/1.5 Summarit.  But I think it is important to understand that the
>Summarit was optimized for mid aperture use for scenic shots and what
>not.  It was designed to provide the additional speed for the
>occasional low light shot but that was not its strong point, and
>wasn't intended to be. It was really a lens designed for amateurs who
>mostly shoot in daylight with an occasional low light shot.  It was
>not intended as a professionals lens for primarily low light use.

The Summarit is basically a weak lens. That it improves after stopping down
is a natural law and no design principle. It has been designed as a high
speed lens and not for amateur use. The weak performance at apertures till
f/2,8 is the result of the limits of optical design of these days, shortage
of optical knowledge and limits of choice of materials. (In a forthcoming
article in Viewfinder it will be explained).At f/5,6 it is at most a decent
performer and will be outclassed by an Elmar 50mm. I once did an
interesting test with a Summarit. Shot pictures (usual precautions) of a
very detailed and textured object. On transparancy the performance at
apertures 1,5 to 2,8 were just bad in comparison with modern lenses. Then I
scanned the trannies and used Photoshop to enhance contrast. Now details
not visible in the real life situation became visible. Upshot: the lens has
a good resolution but its overall contrast and contrast of microdetail is
just bad. Total performance is also downgraded by this behavior

Eric wrote:
>You know, the way Leica is describing this in their new brochure "Leica:
>The Program" it sounds like they intend to make this a series production
>lens. These numbers we're getting, I'm willing to bet are just preliminary
>limits to the numbers they are doing in early production runs. It's
>probably a hard lens to make, since it has an Aspheric lens, right? So it
>might be a few years before they can fill the pipeline with adequate
>numbers to make everyone happy. Otherwise, I would think they'd be charging
>more for it than $3,000 USD.

Actually Leica has a production run of 300 for the Vario 2,8/35-70. It
stops there unless demand is so strong as to justify a new series.


Erwin