[jaapv]

Originally Posted by lars_bergquist

About lens names: Up to about the middle of the 20th century, i.e. before computers, a lens design could consume many man-years of computation, and was something to be very proud of. Designs were few and rare, and the better designs had design names, like Tessar, Sonnar and Planar (Zeiss) and Elmar and Hektor (Leitz). An Elmar for instance was always a 'cemented triplet': One positive lens element followed by a negative (bi-concave one) and the rear brought up by a positive group of two cemented elements.

From about 1950 Leitz got themselves a Zuse computer and created some software for it. New complicated lens design started to spew out, the first being the collapsible 50mm Summicron of 1953. Around 1958 new designs were so many that there was problems with inventing new names. So after that year lens names were basically redundant speed class names, not design names. The first 90mm f:2.8 lens e.g. was actually a Hektor-type design, but was named 'Elmarit', and that has since then meant a 2.8 lens, period. Here are the names:

f:4, 3.5 Elmar (or Tele-Elmar)
f:2.8 Elmarit (or Tele-Elmarit)
f:2.5 Summarit (until 1960 an f:1.5 50mm lens)
f:2 Summicron
f:1.4 Summilux
f:1.2 or 1.0 Noctilux

'Telyt' however has always designated a lens of true telephoto design, irrespective of speed, mostly long lenses for use with the Visoflex reflex attachments.

Leitz/Leica image quality targets have always been extremely high, but they have of course developed with the technology. You can slap many lenses from the late 1950's on a M7 or even a M8 and take very nice pictures, and some people prefer the slightly lower contrast and micro-definition, but they will also have to accept more flare and internal reflexes. The present generation of lenses is generally fantastic in that department.

The old man from the Age of the Summitar

Very good, Lars, but the 400, 560 and 800 Telyts are not telephoto designs, but achromatic telescopes, and the 500/8.0 R is a catadioptric design.