Fed 36 6.3/100mm

This lens is in exceptional condition, you'd think it new, whereas these lenses were produced from 1938 (design 1937), and I guess not after 1941. Produced according to J.L.Princelle at less than 20000ex. rare, therefore expensive, it was provided with a dedicated viewfinder, which has become even more rare (and expensive!), so I don't have one.

Logical showing: on my 1938 Fed 1.

But it will mostly be used on the Sony α7, especially since it is excellent.

Like for many old lenses, it poses problems of "flare".
You could think that the total absence of antireflection coating on the lenses is the cause, not at all, this phenomenon comes from parasitic reflections inside the frame tube.

The proof after flocking this tube: I took advantage of a sunny day for testing, impossible to reproduce the fault!

Although there is no anti-reflective coating, the design in four elements in two bonded groups limit the possibilities of reflections between lenses to a single location, around the diaphragm, I get an image as contrasted as with a "modern" multicoated lens!

Note that the rear part of this lens is very easy to disassemble: one single screw, the largest. And I took advantage of my flocking session to regrease the helicals before reassembly. I have also noted that the thrust ring of the rangefinder is adjustable to fit accurately to the camera.