"Peter" wrote in message
...
On Sep 6, 10:19 am, "LGLA" wrote:
Curious if anyone here uses any old Schneider Xenar 150mm on their 4x5? Can anyone
give a good impression of it's qualities? I know it is a four element in three group design
and related to the tessar design.

Large_Alex

The Tessar and the Xenar (as well as some other manufacturer's house
brands) are very similar. The performance of any used lens should be
evaluated by actual measurement since (for a used lens) it depends to
a degree on how the lens has been handled since manufacture. For
Schneider's lenses, prior to WWII, the quality control was a little
uneven, so if it is an early serial number, extra attention to an
actual test is a good idea. After the middle '50s, Schneider's QC
seems to be notably better. Even so, 1 test is worth many expert
opinions.

Thanks this Xenar was manufactured between 1968 and 1970, probably 1969,
seeing the serial and their chart. This lens I have just attained is in excellent
condition glass-wise. NOW it feels better to me, from your statement.

The primary reason that the Xenar is less widely used than it might be
is coverage, not sharpness. A good Tessar or Xenar can be very sharp
and contrasty. However, the coverage is significantly less than the
Symmar. The Schneider web site gives 62 degrees of cover at f:16 for
a Xenar (see:
http://www.schneideroptics.com/info/...4,5-150mm.html

You mean "angle of View at f/16"? Would that be the angle of light-cone
projected at the film? Which would create an image circle of 180mm OD?
Or is the 'angle of view' how the lens sees the subject compared to wide
angle and telephoto?

Strange they mention this lens to be recommended for medium format,
when that image circle of 180mil = 7.08661417322835 inches, two inches
beyond five inches of film. I should think that would be plenty for nominal
4x5 shooting!

The corresponding claim for the Symmar of a similar age is 70
degrees. My experience with older Symmars is that some of them
'cover' (i.e., illuminate, with poorer quality) even more than that;
this property can be useful, sometimes. If memory serves faithfully,
I think Schneider at one time or another has actually claimed a little
more as the coverage of the older Symmars, but not recently.

Seems pretty evidentt hat little changes for corrections are made in
design-to-production with little mention. I think I read the Caltar II-E has
a slightly larger image circle than the Rod. Geronar.

Broadly, a good 150 mm. Symmar should cover an image circle of about
180 mm. in diameter...

"Should" - but that is the same that is stated for the Xenar 150mil.!

....and some might provide 60 line pairs/mm. over much
of that field if your demand for contrast is reasonable. If it
doesn't do better than 40 (especially in the center) either re-
consider your test method or throw it back.

Right-on, thanks much for the reply indeed. But I was asking about image
qualities by experience, which I now know I should have mentioned. My
apologies for not.

Regards, Large_Alex