Quote Originally Posted by David Lyga View Post
Because of the inability to place the rear element closer to the film plane (the mirror gets in the way) RFs are touted as having superior wide-angle results. We know that this is so in theory and that compromises had (and still have?) to be made with optical formulas in order to 'compensate and correct'...
David, as far as I know there are physical limits in the SLR land and so far big sized lenses with compromises is the only way to go.
What Ian Grant wrote about Biogon and Distagon in the Hassy is a good way to look at it.

In RF land, it was not until 1935 when Michail Russinov (or Roosinov) pioneered the use of aberration vignetting (to improve corner illumination) and designed vignetting filter deposited on the inner surface of the wide angle objective exterior lens..
Also, M.M Russinov pioneered the idea of enlarging the size of the entrance pupil as angular coverage increases..
By 1946 M.M.Russinov lens design (Russar) was patented and documented widely.
Zeiss and Leitz came late to the game and that explains why they used workarounds.

When Ludwig Bertele was commissioned by Zeiss in 1951 to design a wide angle lens for Contax and Hasselblad, Bertele could not obtain master patent for the use of single meniscus at each end of the lens as Russinov had already covered this.

At the International Congress at Stockholm in 1956 Ludwig Bertele paid tribute to Russinov for his highly interesting and original solution to the problem of securing adequate illumination in the picture corners etc. etc..

In 2011 Dr. Hubert Nasse, senior scientist at Zeiss and chief optical designer wrote in Camera Lens News 41 published by Zeiss Carl Zeiss AG Camera Lens Division:
"In 1946 the first patent for a new kind of symmetrical wide-angle lens was applied for by the Russian lens designer Michail Roossinov. It looked as if two retrofocus lenses had been combined with the rear elements together and thus had a symmetrical arrangement of positive refractive powers close to the aperture, surrounded at the front and back by strongly negative menisci.
As of 1951, Ludwig Bertele carried this idea further and designed the legendary Biogon on behalf of Zeiss..."