Re: [Leica] WA infinity performance

[Erwin Puts <imxputs@knoware.nl>]

> I have been thinking seriously about the 35 lux-ASPH for this purpose but
>this discussion suggests that this might not be the best lens. The problem
>with the N 35 1.4 is there is a lot of coma - the lens is comatose!!!
>Stars (the short 10 to 20 sec.  exposures resolve the stars as points) in
>the center look ok, but those on the periphery look disturbing and draw
>attention away from the AB. I also noted this on shots I took of Hale-Bopp
>(multiple comets!!!- stars plus the real one). Maybe the original
>ASPHERICAL or 35 lux would be better for this purpose??????????

Tom,
As far as my limited knowledge permits, may I suggest that the whole
discussion about optimum corrections at different distances is very shaky.
All lenses are corrected for infinity (the exception of course are the real
Macro lenses). That also means that all lenses suffer from optical defects
as they are focused upon objects not at that distance. Some lenses indeed
are better at 1 meter than others. A case in point is the 28mm Elmarit-M,
which had a positive performance boost at a distance from 1 to 2 meters
when the current generation came about. On the other hand the first two
generations of the Elmarit 28 were somewhat weak at infinity, where the
newer ones excelled. The Summicron-M 2/90 also needs a bit of a
connaisseurs-treatment at full aperture and 1,5 meter.
If a lens is better at short distances than another one, then this is not
related to a conscious decision to correct for medium distances at the
expense of the infinity setting. It has to to with the general state of the
corrections in sum.
Many people seem to be unhappy with the infinity performance af modern
wide-angles. I know of two persons who compared their M-24 to their also
new M-28mm .The 24mm, they considered inferior at the infinity setting
compared to the 28. The factory however tested both lenses and found no
significant deviation from their norm.
I do think that at infinity there are two contradictory factors at work.
First of all, at that "point" the performance is at its best, but
the objects at infinity are very reduced in scale so the lens has to be at
optimum contrast and resolution to be able to register these details. A
slight shake, a litle atmospheric haze, a bit overexposure etc and gone is
your quality.
The original 35ASPH is so equal in performance to the current one that a
discussion about the differences amounts to asking for the impossible.
Their are some diffeneces but not for us mortals.
I propose you try the 35/1,4-ASPH for your purposes.
Erwin