The Voigtlander 65mm-APO Z lens Compared

[MEPER]

Interesting...... :-)
The compensating type has the "scalloped" (hill and dale) focus ring.

[Michael Erlewine]

This is what I have.

[MEPER]

That is the one :-)
Maybe you can check first with a single frame is you are satisfied with 3.5 or 5.6 is better.
Probably at high magnification 3.5 will give higher resolution.

[MEPER]

It it easy to check if it "compensates" if set to e.g. f/8 and lens is at infinity the aperture will open up when lens is focused closer.
At 3.5 it will just stay at 3.5.

[Michael Erlewine]

It it easy to check if it "compensates" if set to e.g. f/8 and lens is at infinity the aperture will open up when lens is focused closer.
At 3.5 it will just stay at 3.5.

Please explain more just how "compensating" works in a lens.

[MEPER]

As far as I know this is the only F-mount Nikkor that compensates the aperture when focused closer.
It will compensate for the loss of light which occurs when magnification gets higher (focused closer).
It the old days where you did manuel measurement of the light you only need to do it once at one magnification and the lens will make the adjustment when focused (but not at 3.5).
Nikon may explain it a bit different but that is the idea. If camera has light measurement through the lens like modern camera bodies it is not at problem.

Richard also like the lens (the compensating mechanism is showed):
https://richardhaw.com/2017/01/18/repair-micro-nikkor-p-55mm-f3-5-auto/ 

[MEPER]

An easier way to explain the light loss with higher magnification is that the length of barrel increases when focused closer so light has to travel longer. 

[Michael Erlewine]

Here are three photos.

(1) 55mm f/3.5 COMP stacked on center and finished as the others.

(2) 55mm f/3.5 COMP untouched single shot

(3) 55mm f/5.6 COMP untouched single shot

[MEPER]

Thank you very much for this comparation.
It confirms that it is a fine lens?

There is a difference in background blur. Not that the 55/3.5 looks bad but with 65/2 it is more "blurred" like "vaseline".
Also it looks like with 55/3.5 the front red leaf of the flower has a bit more DOF so more of it is in focus?

[MEPER]

The resolving power of the 55/3.5 may be a bit higher at 5.6 if I look close to the monitor with +2 glasses.
It seems the 65/2 does this already at f/2.
Still I am impressed by the old 55/3.5 with only 5 lens elements.