[Leica] Zeiss Normal 50mm f/2 Planar T* ZM

[sethrosner at nycap.rr.com (Seth Rosner)]

Hello friends!

I unsubscribed from the LUG months and months ago as I was traveling and 
couldn't bear to return from a trip to 1500+ LUG emails. I resubscribed to 
the digest and hadn't figured out how to respond to a thread and inject my 
2c. Happily, I just returned from the LHSA annual meeting in Seattle that 
embraced a wonderful LUG dinner last Friday at one of the best fish and 
seafood restaurants I've ever experienced; with Mark and Henning and Greg 
and Tom + Tuulikki and Peter and I'm certain to leave some good friends out 
so need to leave out several. They told me how to respond to a thread and I 
hope I have remembered the key to lugging-in.

And as some of you know, I cannot leave my mitts off a Summicron debate, 
especially when it involves Erwin Puts. I'm so out of it that until I read 
this thread, I had not realized that he has left being a Leica Camera tout 
and become a Zeiss/Cosina tout. Fascinating. P.S. I learned in Seattle that 
marc small has left the LUG so I am more or less safe since it was marc who 
several years ago threatened me with a defamation action for having written 
critically of Erwin's evaluations.

So I took the time to look at Erwin's report on this Zeiss lens. Here is 
what he writes about this lens in Phase 2:

"Planar-T 2/50 ZM
"For several generations the Planar design has tried to challenge the 
Summicron 50mm and never became as good. Now at last we have a lens that 
equals the Summicron-M 50mm and is even a trace better in the curvature of 
field area. The optical performance of the Planar is simply as good as that 
what can be expected form the Leica Summicron. The Double-Gauss design has 
been studied exhaustingly and it is now possible to equal but not surpass 
the Summicron design as long as you stay within the D-G limits. It is worth 
some study to note that the curved elements of the Planar bring no 
significant improvements in comparison to the many planar surfaces of the 
current Summicron.
"This conclusion makes the claim of some Leica collectors, that the current 
Summicron is a lesser design than the all-curved predecessor, somewhat 
hollow."

Many of you know that I am enamored of and have studied the 50/2 DR/Rigid 
Summicron exhaustively. In fact following the optical bench tests of the 
35/2 Summicron 8-glass, the pre-ASPH 35/2 Summicron and the 35/2,8 Summaron 
that were the basis for my article in LHSA Viewfinder, I have had the same 
optical bench tests done by optical genius   ;-)  Roy Youman at Optikos 
Corporation on my 50/2 DR Summicron, the vaunted ALPA Kern 50/1,9 
Macro-Switar and the hugely under-appreciated Leitz/Leica 60/2,8 
Macro-Elmarit. For a forth-coming Viewfinder article.

First some basics. The DR/Rigid Summicron does indeed induce some flare at 
f/2 and 2,8, created by the so-called "air-lenses" between the first two and 
second two lens pairs. That flare disappears somewhere between apertures 
f/2,8 and f/4. The 50 Summicron introduced in 1969, 11817, was specifically 
designed for best possible performance at the widest stops, ergo, to reduce 
flare and at those stops, in flare-inducing photographics situations, it is 
an improvement over the DR/Rigid. At f/4 and further stopped down, the 
DR/Rigid's contrast = suppression of flare, is as good or better than 11817 
whose MTF charts are significantly worse than the DR/Rigid. The next - and 
current - 50 Summicron improved very significantly on 11817 in both contrast 
and resolution but the resolution of neither matches that of the DR/Rigid. 
Read carefully here, I do not mean to suggest that the DR/Rigid will never 
flare at the smaller stops, say f/8 and smaller. Only the later 
Leitz/Leica - and other - lenses, the Noctiluxes being phenomenal examples, 
have so remarkably suppressed flare and coma so that you can photograph 
bright light sources within the frame and reproduce only the light itself 
and no surrounding glow. All of the Summicrons - and the Planars - will 
produce flare with light sources in the frame and in contre jour, 
backlighted situations.

Now, let's go back to Puts. As usual, Erwin mixes and matches to lead to an 
incorrect inference, thinking that it will not be noticed. He writes that 
the Planar "equals the Summicron-M and is even a trace better in field 
curvature". He is comparing the Planar to the current Summicron, NOT to the 
DR/Rigid. He could not possibly make that statement about the DR/Rigid 
because that lens has a remarkably flat field and absence of field 
curvature. Why? Because it was designed not only for general photography but 
for close-up work as well, where absence of field curvature is essential, 
ergo, the famous viewfinder "goggles" or "bug-eyes". To Erwin's credit, he 
acknowledges that "it is now possible to equal but not surpass the [current] 
Summicron design as long as you stay within the D-G limits". But he is not 
comparing it with the DR?Rigid. He nowhere in this report claims that his 
now-beloved Zeiss 50/2 Planar equals, let alone exceeds the DR/Rigid 
Summicron. You really have to read this guy carefully; he's been bobbing and 
weaving like this in his writing for years.

But he then immediately seeks to confuse the issues again by writing: "This 
conclusion makes the claim of some Leica collectors, that the current 
Summicron is a lesser design than the all-curved predecessor (the DR/Rigid), 
somewhat hollow." This sentence IS A PERFECT NON-SEQUITUR.

I have somewhere in my collection of Puts-isms a writing by him that the 
current 50 Summicron introduced 5 plane surfaces in order to reduce 
manufacturing costs (that would be both glass and assembly) and in a 
different writing that when this is done, image quality is not maintained. 
Understand, friends, that every lens, by any manufacturer, is a compromise. 
The current 50 Summicron has better overall optical performance than the 
DR/Rigid at the first two stops IN HIGH FLARE SITUATIONS. Otherwise the 
DR/Rigid  still delivers the best overall optical perfomance available among 
these lenses.

And of course even Erwin has often acknowledged that the build quality of 
all of the Leitz lenses from the 1950's, '60's and very early '70's has 
never since been equaled.

At the same time, I have to say that the optical performance of the new 
50/1,4 Summilux-ASPH is absolutely astonishing, straight across the board. 
The ONLY comments about it that I have heard or read that were not entirely 
complimentary related to a certain edginess or harshness that probably 
derives from its design purpose of maintaining extraordinary high contrast 
at all stops and acrossd the entire film/sensor plane.

Now to Erwin's in installment 3:

"Planar-T 2/50 ZM
"Wide open the lens shows excellent neutrality of colours with amazingly 
good retention of fine colour hues. Very fine detail is recorded with good 
clarity, but with less crispness than the Leica counterpart. It shares with 
that lens the weak suppression of secondary reflections, due to the 
reflections at the edges of the rear mount. The background blur is on the 
harsh side.
The transition from the sharpness plane to the unsharpness regions however 
is quite long, giving a fine impression of depth and extension. The lens is 
especially good at recording detail in extended shadow zones, when you take 
pictures at dusk or at night.
The background blur shows the major outlines of the subject shapes, more 
sketching than drawing so to speak. Close up performance is excellent from 
centre to edge without any vignetting and distortion.
The Planar wide open is a potent performer and at smaller apertures becomes 
a master at reproducing with a life-like three dimensionality, that was the 
hallmark of the G-version of the Planar too."

So let's analyze:

"Very fine detail is recorded with good clarity, but with less crispness 
than the Leica counterpart."

In Erwin-speak, this means that the current Summicron-M has better edge 
contrast than the Planar. It will be clearly inferior to the DR/Rigid except 
in the photo situations noted above.

"It shares with that lens the weak suppression of secondary reflections, due 
to the reflections at the edges of the rear mount. The background blur is on 
the harsh side."

First sentence is a comparison with the current not the DR Summicron. The 
second sentence is an acknowledgement of bad bokeh.

As a famous Irishman said in his allocution whilst standing upon an English 
gallows:     I am done.

Seth