Zeiss Opton Biogon 2.8/35 vs Zeiss Skoparex 3.4/35

[iangreenhalgh1]

I feel really lucky to have both of these in my hands, the Skoparex is mine, the Biogon belongs to a lucky friend. Both are really nice lenses, the Skoparex is a Voigtlander design for Icarex, a 5 glass retrofocus tessar type. The Biogon is a thing of beauty, such amazing build quality with the shiniest chrome I've seen on a Zeiss lens, it's immensely heavy for it's size so surely brass and the focus is so smooth. It's the post-war redesigned lens so it fits on the NEX and with the way it is recessed into the adapter, it forms a really small and sexy package.

These were on my NEX-3 at 200 ISO, using a Cullman flash bounced off the ceiling, both lenses were wide open. I'll let you guess which is which. Unsharpened 100% crops.

Lens A:




Lens B:

[patrickh]

I would happily take either


patrickh

Nice portraits

[iangreenhalgh1]

Cheers Patrick. I think A is sharper but B has better contrast. That might be a big clue to those who know these two lenses.

[Hari]

Lens A - biogon, Lens B - skoparex?

logic behind my answer - less in focus and more out of focus in picture A which might be because the lens opens up to f2.8

more in focus and less out of focus in picture B which might be due to the f3.4

has my "real world" answer made any sense?

[yinyangbt]

Lucky you to have a lucky friend !
Lovely portraits ,Ian !

[hifisapi]

they both seem very similar and excellent to me.....

[std]

My bet is that the Skoparex is A.
The Biogon will have more pop (as on pic B).

[hoanpham]

[stilian]

A - Skoparex
B - Biogon

99% sure

Can you please post a photo of the Biogon Nex combo ? Thanks in advance !

[std]

I also think that the biogon will show more vignetting on Nex and the OOF rendering will be more busy - like on second image. Skoparex renders oof very nice and smooth.

[JohnBar]

Hmm they look a bit woolly to me.

However, the gentleman with the empty glass on his head looks in need of a refill.

[Orio]

Vignetting would be a very useful criterium to discriminate between a retrofocal and a non-retrofocal wide angle lens.
Unfortunately, it is not applicable here because the camera is crop format, so we're not seeing the real angles.
It would be easier if the comparison was made on film, with full format camera.

Both lenses appear to be equally resolving. I.e. the details appear to have the same fine resolution in both images.
The first image shows residual spherical aberration, which reduces the micro-contrast and thus impacts on the general
sharpness perception.
Yet, it is still very difficult to tell. Both lenses are post-war and so they are both coated.
I am unable to make an educated guess.

P.S. if you show a geometry test before giving the answer, I may try a guess

[iangreenhalgh1]

Orio has some interesting thoughts that I agree with. I can shoot the Biogon on film, but not the Skoparex as I don't have an Icarex.

In lieu of an answer, here are further samples, same order again, both lenses were at f5.6, again using flash bounced off the ceiling. Weather is atrocious here so I'm stuck indoors atm. No PP on these, just resize for web.

Lens A:



Lens B:

[iangreenhalgh1]

It's unbelievably wet and dark here, no chance of shooting outdoors. Best I could manage was to point the NEX out my back door.

Both of these are wide open at 1/40 sec, ISO 200, which gives you some idea how dark it was at 1pm. Roll on spring is all I can say!

Lens A:



Lens B:

[iangreenhalgh1]

Some more shots with flash bounced off the ceiling, which seems to work very well. Both at f5.6. I think these are both great lenses, really is not much to chose between them. No PP on these shots, just resize for web..

Lens A:




Lens B:

[fermy]

[iangreenhalgh1]

[iangreenhalgh1]

Well, time to reveal that Lens A is the Skoparex and lens B is the Biogon. I decided to sell the Skoparex and buy my own Biogon:

http://forum.mflenses.com/contax-iiia-with-zeiss-opton-biogon-2-8-35-t54804.html