optical scheme of elmar 3,5 cm f/3.5 lens of thirties

[luis_sanchez2]

Please, I?d like if somebody can tell me how many groups and elements has got

the Elmer 3,5 cm f/3.5 of thirties made by Max Berek and if possible also the

optical scheme of the Elmar 5 cm f/3.5 also from thirties.

[john_shriver]

A classic Tessar: four elements in three groups.

 

Unlike the 50mm Elmar, it's a true Tessar, since the iris is in the conventional place. The 50mm Elmar has the iris further back in the lens.

 

The corner sharpness wide open reflects the fact that it's a Tessar, and that stretching a Tessar for a wide-angle application is, well, a stretch.

[luis_sanchez2]

Thank you very much, John. You have made me feel as when watching 1986 NBA Long Distance Shooting won by Larry Bird or the legendary b & w videos of the ten NCAA Championships won for UCLA by the great John Wooden, seven of them consecutive.

 

My respects

[alex_lofquist]

I couldn't find a diagram of the 35mm f/3.5 Elmar. (I actually had one 50 years ago.) I did find one for the 50mm screw mount Elmar as published in 1954. The first element is a plano convex crown glass lens followed by the aperture diaphragm. Next is a double concave flint lens, then an achromat planoconcave cemented to a double convex lens. That's a surprising place for the aperture stop, though it may have reduced the distortion at the expense of fall-off.

As John suggested, it is not a good wide angle lens. I had to stop mine down smaller than f/4.5 to get rid of the severe vignetting, and much more to get really good quality images. Eventually I traded it off for a 35mm f/3.5 Summaron. Very good!

[mpo]

Here they are.

 

If you are interested in these topics, get the excellent book "Identifying Leica Lenses" by Ghester Sartorious.<div></div>

[adrian bastin]

Look for the work of James Ravilious - this, uncoated, was his lens of choice and he used it to wonderful effect, despite it's limitations. Interestingly, in regard to above comment, he also loved the early Ziess Tessars (pre-WW1) for LF work.

[adrian bastin]

Or 'Zeiss' even!

[Troll]

I note that some 75 years after the original Elmar, the aperture was moved back to the original Tessar location for the "O" Leica, reputed to have the best performing 50mm lens ever tested at PoP.<P>What a pity that Leica chose not to make it available separately.