Contax-Zeiss 21mm lens

ljsegil

Well-known
Local time
5:20 PM
Joined
Jun 14, 2006
Messages
206
I am thinking of purchasing a 21mm f/4.5 Zeiss Biogon. Can anyone tell me how this lens compares to the VC 21 mm lens? Obviously, I am most concerned with image quality, but handling is also important.
Thanks ahead of time for your assistance.
 
I don't own a 21mm CV Skopar, but I just did a comparison shot between the 1953 Zeiss Biogon 21/4.5 in original Contax RF mount compared to the CV Skopar 25/4. Both shots at minimum focus of 3 feet, wide open, 1/30th shutter speed. (EDIT: Maybe faster shutter speed. Now that I look at these, I think the shutter speed is closer to 125 or 250).

First shot, Biogon:
attachment.php


Second shot, Skopar:
attachment.php
 

Attachments

  • 21biogon-mar07.jpg
    21biogon-mar07.jpg
    83.5 KB · Views: 0
  • 25CVSkopar-Mar07.jpg
    25CVSkopar-Mar07.jpg
    89.7 KB · Views: 0
Last edited:
Some notes on Biogon vs. 25/4 Skopar.

Both lenses nearly identical in size. Biogon weighs 275g (9.7 oz); Skopar weighs 160g (5.6 oz).

Both lenses: Minimum focus 3 feet /0.9 meter.

Skopar, click stops at half-stop intervals. Biogon, no click stops.

With the Skopar, depth of field scales and aperture settings can be read from the side of the lens. With the Biogn, depth of field scales and aperture setting can only be read from the front of the lens.
 
Both lenses render the scene beautifally. The Biogon seems to have more contrast, and the 21 CV has somewhat better resolution, and less contrast. Results with both lenses are outstanding.

Choose the one that you prefer. I vote for the Biogon, personally, but I am a fan of antique Zeiss lenses.

WRT handling, the CV may be better, given that it has click stops/detents on the aperture scale.
I use both lenses, and love them equally. Bear in mind that depth of field on a 21mm lens is so huge that focusing is usually irrelevant. Click stops on the aperture may not be an issue in many cases
 
Last edited:
Maybe it's the angles of the shots, or the distance from the girls, but it looks like the Skopar is less distorted. I really like that shot.
 
I've never cared for 21mm compared to 25mm. For me, the extra 4mm on the wider lens is nearly always too distorted, whereas a 25mm can be used in just about any circumstance. It's not a factor of the specific lens but of the 25mm versus 21mm field of view and perspective.
 
Personally, I have never understood either 25 or 28 fields of view. I really like 21 and 35mm FOV, but the intermediates don't work for me. To each his/her own.
 
>>To each his/her own.<<

Absolutely! I know I'm very much in the minority and that most RF users prefer 21mm over 25. I used the Biogon 21mm lens for more than 15 years, often wishing it wasn't quite so wide. Finally, I bought the 25mm Skopar last year and don't carry the Biogon much any more.
 
Vince

The colors in the Biogon shot seem crisper - probably the increased contrast as was mentioned. I just love the rendering that lens gives. Remember, the Biogon is from 1951 or there about. What a great job Zeiss did in designing this lens, to get the color, levels of distortion, contrast just so right IMO.

I never used a 28mm much until I bought one for my M4, now I use it all the time. I bought a 24mm Elmarit new and sold it several years ago....couldn't get use to that particular focal length. I would rather shoot with a 21 if I want to go wider than 28mm.

Yes I agree, to each his own....that's why they make different focal lengths.
 
21mm Redux

21mm Redux

Please forgive my rudeness in bumping this thread, but I am still desperately seeking people's experience comparing the 21mm f/4.5 Zeiss Biogon for the Contax IIa and IIIa with the Voigtlander Cosina 21mm offering. The comparison shots that Vince provided are very helpful and appreciated (any more?), but I am hoping the community can provide still more to guide me in my wide angle quest.
Thanks very much,
LJ Segil
 
LJ, do bear in mind that the Biogon will shortly be reissued in updated form, for the M mount.
The Contax-mount lenses regularly fetch $650, and I think I've seen that the new lens might be available for under $1000 if you look hard, which seems like a good deal. Altho it won't have the jewel-like construction of the original it will have improved coatings etc. I used to own the VC 25/4 - it was terrific value for money, but I found it too contrasty, black and whites were never rendered as well as with my Zeiss (and even Jupiter) lenses. So I spent some time looking for the Contax-mount Biogon... but have now transferred my yearning to the new M mount lens, if it's available at a good price.
 
I've heard that some CV lenses are based on the Tessar - as are many other lenses - but I didn't know that other lenses were based on the Biogon. I couldn't see any specific mention of this on the links you mentioned, either. Which CV lenses, derived from the Biogon, are you talking about??
 
My sense without any real expertise, is that Zeiss has not always been very scientific or technical when matching lens names with lens designs. The Biogon name is also used for their 35/2.8 from the 1930s, and this lens behaves very differently from the 21/4.5 of the 1950s. The 21/2.8 may use a different formula entirely (I don't know).

The CV lenses do not use the same formula as the 21/4.5 of the 1950s. The CV lenses sit much further from the film plane and so use some retrofocus elements in their design. They entire optical assembly is not as long as either classic biogon.
 
VinceC said:
My sense without any real expertise, is that Zeiss has not always been very scientific or technical when matching lens names with lens designs.

It is my understanding that the current use of the name Biogon is as a tradename not as a description of an optical formula. I think the current Biogons have nothing whatsoever to do with the classic lens formula from the 1950s. Similarly the current 50mm f1.5 Sonnar, while at least derived from the original formula, is not the same.

There is an old advertising principal that states the further your product is form the real thing the more you evoke the real thing. Ergo ads for artificial lemonade portray a frosty pitcher, a guy wearing suspenders on the back porch in a rocking chair and lemons lying about on the table.

Michael
 
"Which CV lenses, derived from the Biogon, are you talking about??" - Paul

This is what the flicker biogon admin seems to see as biogon designs for CV:
COSINA/VOIGTLANDER
12mm f/5.6 Ultra Wide Heliar
15mm f/4.5 Super Wide Heliar
21mm f/4 Color Skopar
25mm f/4 Snapshot Skopar
28mm f/3.5 Color Skopar

Biogon
Schnitt_Biogon21.jpg

Distagon
Schnitt_Distagon40.jpg

Planar
Schnitt_MaPla60.jpg

Sonnar
Schnitt_Sonnar180.jpg

Tessar
Schnitt_Tessar45.jpg

(images from Zeiss site)
CV 21mm f4 CS
21mmlensconstruction.jpg

(images from Chiif camera)
They are all similar to the biogon design from comparisons with available element designs but seems the closest is the 21mm which almost looks like a replicate. See http://www.chiifcameras.com/content/view/15/42/ Most of the CV lenses above protrude deep into the camera cavity and have relatively symmetrical elements layout to the original biogon design.

I'm no expert in lens design so dont quote me on this. What I've gathered is from the same info available out there.
 
Last edited:
Seems to me that Kobayashi -san is such a vintage freak that, if the 21mm were a homage to the Biogon, he would have said so. I can't help thinking that being grouped together on flickr isn't good evidence for the lenses being related.

Not that it matters... but from a practical point of view the VC 21mm and 25mm vignette, especially on the R-D1, whereas the new Biogon designs are much better, which was another reason I'd be surprised by a relationship between them. Altho, of course, Zeiss have also been accused of being cavalier about model names.
 
Back
Top Bottom