Thank you very much for posting this. I don't think I have
ever seen this brochure.
I think Kingslake discusses this lens in his book on lens
history. Paul Rudolph had retired but lost his money due to the
war (WW-1) and had to go back to work. He was hired by Meyer and
designed the Plasmat for them. It seems to me this was not quite
a new design. The Plasmat is essentially a Dagor with the inside
element of the cemented triplet broken out and air spaced. This
arrangement allows correction of the zonal spherical aberration
typical of all cemented triplet types. The lens does not have
quite the coverage of a Dagor but works at large apertures
without softness. The Plasmat type became very widely used for
large format lenses. Its main drawback is flare due to having
eight glass air surfaces but with coated lenses this is of little
consequence. Lenses like the Schneider Symmar and Rodenstock
Sironar are Plasmat types of very high performance.
Meyer, BTW, made a rangefinder in competition to Kalart and
offered on Speed Graphics and other cameras. Its drawback was
that it was made for a specific focal length and while adjustable
for small variations to fit an individual lens, could not be
adjusted to cover a range of focal lengths as could the Kalart. I
have no idea of the relative quality but one sees few of them on
cameras. Perhaps they were more expensive.
On 8/10/2020 2:06 PM, Eric Goldstein wrote:
Nothing at all to do with Rollei or Zeiss except for the good
doctor... but had to share this beautiful brochure with someone.
I bet those double plasmats were kick ass lenses
http://www.ihagee.org/Lenzen/HMG3-1938E-PlasmatLenses.pdf
Eric Goldstein
---
Rollei List
- Post to rollei_list@xxxxxxxxxxxxx
- Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe'
in the subject field OR by logging into www.freelists.org
- Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with
'unsubscribe' in the subject field OR by logging into www.freelists.org
- Online, searchable archives are available at
//www.freelists.org/archives/rollei_list
