IMO the white F / red T issue finds its roots within the Zeiss Ikon company splitting when the WWII ended.
not sure (see previous message)
I mean, Carl Zeiss Jena invented and developed lenses coatings in the late 1930's (I have one of those rare Carl Zeiss Jena Sonnar 50/1.5 T coated lenses in Contax mount, mine was made in 1938 according to the s/n). For a reason I don't know (a Zeiss specialist would tell this) they called it "T" and so marked their newly coated lenses.
Interesting rare lens, could you send me the serial number (PM) for the registry so that we can spot the prewar T batches (I own a sonnar f2 226$$$$ who is also T lens)..? T woudl mean "Tranzparenz"
After the war, there were court disputes between the East-German Zeiss and the West-German Zeiss (to make it short) about the use of the "Contax" brand and, probably, the marking on coated lenses, hence the West-German Zeiss lenses manufacturing plant (Oberkochen) having to use a white F instead of the red T on their first coated lenses series, the red T being considered to be the proprietary TM of the East-German Zeiss lenses manufacturing plant (Jena). Which resumed eventually, allowing the West-German Zeiss lenses manufacturing plant to use the red T on their new "Zeiss Opton" lenses (on their late "Carl Zeiss" lenses, they abandoned the red T while of course their lenses remained coated the very same way).
Not sure at all... we are working on it...
The most confusing thing may be the early East-German lenses (from 1947 up to 1951) which were either specifically designed for the new Contax IIa camera (I think of the East-German Carl Zeiss Jena Sonnar 50/2 T) because the West-German Zeiss lenses manufacturing plant wasn't ready to produce lenses while the West-German Zeiss Ikon camera bodies manufacturing plant (Stuttgart) was releasing the IIa camera already, so that the early West-German Contax IIa bodies series were sold with East-German Carl Zeiss Jena Sonnar 50/2 T "kit" lenses as a result of the commercial trading between the two Zeiss.
There is a common confusion between allied occupied Germany and the BRD (created may 1949) and the DDR (created october 1949... till then there is only one Germany... and one law... so there is no East German production lenses but only the continuation of production of Carl Zeiss Jena (with the new numbering above 3000000 occuring in 1948 or early 1949...)
Plus, at that time, Carl Zeiss Jena continued to produce some lenses which either wouldn't mount on the new Contax IIa/IIIa like the Carl Zeiss Jena Biogon 35/2.8 T (same lens as their prewar heavy metal shell but made of aluminum and now wearing the T coating) or, although being Contax IIa/IIIa compatible, lenses that rarely got out of Germany like their Orthometar, Biometar, Biotar, and their mythic 25/4 Topogon which was the very first superwide lens designed for the Contax rangefinder system ; interesting tip is that Carl Zeiss Jena (East) making the 25/4 Topogon had Zeiss Ikon Stuttgart (West) make their #440 turret finder with 25-35-50-85-135 frames ; when Carl Zeiss Oberkochen (West) later released the Carl Zeiss 21/4.5 Biogon the (otherwise identical) #440 finder then had 21-35-50-85-135 frames.
even at the coldest of the cold war both companies had "informal and scientifical links", you can have a trial and still make business... to my knowledge orthometar is strictly a prewar (wich means pre 3000000) lens...
They (Carl Zeiss Jena, East) also continued to manufacture lenses which could mount on either the prewar of postwar Contax cameras, and which costed less than the new West-German lenses (Carl Zeiss Jena 85/2 Sonnar T, Carl Zeiss Jena 50/1.5 Sonnar T, Carl Zeiss Jena 50/2 Sonnar T, Carl Zeiss Jena 135/4 Sonnar T). Most of these postwar East-German CZJ lenses were made of aluminum or of a mix of aluminum and chrome plated brass. Some postwar Carl Zeiss Jena 50/2 Sonnar T lenses were fully made of chrome plated brass.
Post war CZJ sonnar 50/2 collapsible are very rare...
I have an early postwar Carl Zeiss Jena 85/2 Sonnar T, it's made of a mix of aluminum and chrome plated brass. It came with a "Torpedo" 85/135 external finder, that finder was made in East-Germany according to its Carl Zeiss Jena markings, yet it wears the "IIa" engraved mention on its shoe, revealing that it was an East-German Zeiss finder newly designed for the West-German Contax IIa camera. Interesting.
Interesting indeed, to the same extent, the contaprox tessar 3,5 lens is usually a jena lens in a stuttgart contaprox... they were working together...
AFAIK a postwar West-German Biogon 35/2.8 in Contax RF mount sells for $350, average, was it a Zeiss Opton 35/2.8 Biogon T or a Carl Zeiss Biogon 35/2.8.
