Quote Originally Posted by Ole View Post
The Tessar was redesigned repeatedly, all the way from the original patent to around 1980.

Whether any of these "tweaks" affected contrast and flare, I do not know.
I agree with that, but it appears there may have been a big re-compute / re-design in the early 30's. Optical glass had changed significantly allowing much faster lenses like the f2 Summar etc.