21mm Biogon - ZM - Thoughts?

[NortheastPhotographic]

How are the ZM lenses, such as the 21/2.8 or 4.5, holding up against newer Voigtalnder lenses such as the 3.5 Skopar or 1.8? It seems like Zeiss has walked away from the M line after the 35/1.4, and CV is producing some really great optics now. Just wondering if the Biogons on film still have something to offer over the Ultron or Color Skopar?

In SLR'ville, I used the Distagon and felt like it was really good...so I have always wanted to try the Biogons.

From personal experience I can say the 35/2 felt a bit underwhelming...but the 28/2.8 was stunningly good.

 

[Pieter12]

I don’t have the ZM, but I do have the Zeiss Biogon for the Contax G. A fabulous lens.

 

[awty]

Optically there's probable not enough difference that I would spend twice as much, especially as I seldom go wider than f4. Not a fan of shallow depth of field.
Im more interested in how they operate, wide should be small, have no knobs on the F stop dial to accidently knock, should have half stop clicks. The focus dial should have one plain knob like earlier lenses.
A short throw from up close to infinity.

 

[mshchem]

I have the 21 Cosina Zeiss, great lens. I very rarely use it, bought it used Ebay from a seller located in Japan. Beautiful condition, I have a 35 f2 and the 35 2.8, the 2.8 is really compact. These lenses are a bit expensive new compared to the Voigtlander offerings. Cosina does a great job with Leica mount lenses.

 

[Henning Serger]

One factor I really appreciate at Zeiss is that they publish the MTF data of their lenses from real life tests. Really measured data of produced lenses.
Not like other manufacturers who only publish idealised theoretical data.

ZEISS ZM Lenses | When you go your own way

www.zeiss.com

https://www.zeiss.com/content/dam/consumer-products/downloads/photography/datasheets/en/zm-lenses/datasheet-zeiss-zm-biogon-2821-en.pdf

Other points I really like:
- their very good customer support
- the lenses of the lines have identical colour rendition, so no problems at all when you change from one Zeiss lens to another
- I just love the Zeiss colour rendition: saturated with a very nice warmth to it; I much prefer it e.g. to my Nikkor lenses
- Zeiss lens designers generally pay special attention to a very good differentiation of the focussed subject in the picture in relation to the unsharp aeras: that results in a kind of very nice three-dimensional impression, a "3d-pop".

When Zeiss introduced the Zeiss Ikon ZM I was really tempted, tried it on the camera fairs, but in the end I realized again that an SLR works much better for me than a rangefinder.

Best regards,
Henning

 

[Rob Skeoch]

I use a few of the Zeiss lenses, but none of the Voitlander models. I had the 21mm f2.8 in the past but wasn't using it that much and sold it off. I still have the 18mm and 25mm so don't miss the coverage from the 21mm.
I have also used the 21mm C f4.5. It's great on film but has very bad fringing on digital and was placed 'end of life' by Ziess a few years ago. Same with the 35mm f2.8. Great on film but not so great on digital, so they stopped production.
Years ago I bought a new 21mm f2.8 from Leica. It was a great lens but I didn't use it that much so sold it off. Those were the days of being a full-time news photographer and I didn't carry gear that I wasn't using because of the weight. A 21mm was considered crazy wide back then.
All in all, I would consider the f4.5 model if you're using film outdoors since it's sharp and small.
I'm sure your mileage will vary but I'm drawing on my years owning 'therangefinderstore.com' and years as a working pro for this advice.

 

[250swb]

The M mount Biogon 21mm f/2.8 is a very fine lens, cooler in tone but more micro contrast than Leica lenses and as was said above as impressive as the Contax G version. Now whether micro contrast trumps sharpness is difficult to determine given with film every parameter is open to interpretation every time a different film and developer is used. But if the datum point is C41 where nothing changes other than film type I think the sharpest 21mm images I've ever had are with the Contax G 21mm and the ZM 21mm.

 

[etn]

How are the ZM lenses, such as the 21/2.8 or 4.5, holding up against newer Voigtalnder lenses such as the 3.5 Skopar or 1.8? It seems like Zeiss has walked away from the M line after the 35/1.4

I think Zeiss moved on because they had a full range of M lenses, no need to develop more. As far as performance go, they are ranging from very good to excellent. (also look at the many threads comparing Hasselblad lenses in the MF forum)

The way I see it, Leica lenses are more compact than the ZM for the same performance, which comes at a (high) cost.

What did you find underwhelming with your 35/2? I like mine a lot (by the way, the 35/2.8 is better than the 35/2), although I use the Voigtlander classic 35 /1.4 more those days, for its more classic look and very small size.

I have no experience with the 21mm ZM, when I was looking for a wide angle I was hesitating between the 21 and 25 and went for the 25. The 21/4.5 seems to have a similar optical formula as the Hasselblad 38mm (SWC), which speaks for itself.

I'm interested to read what others have to write on these topics.

 

[NortheastPhotographic]

I think Zeiss moved on because they had a full range of M lenses, no need to develop more. As far as performance go, they are ranging from very good to excellent. (also look at the many threads comparing Hasselblad lenses in the MF forum)

The way I see it, Leica lenses are more compact than the ZM for the same performance, which comes at a (high) cost.

What did you find underwhelming with your 35/2? I like mine a lot (by the way, the 35/2.8 is better than the 35/2), although I use the Voigtlander classic 35 /1.4 more those days, for its more classic look and very small size.

I have no experience with the 21mm ZM, when I was looking for a wide angle I was hesitating between the 21 and 25 and went for the 25. The 21/4.5 seems to have a similar optical formula as the Hasselblad 38mm (SWC), which speaks for itself.

I'm interested to read what others have to write on these topics.

They did develop a very good line of lenses for film, but as soon as it became apparent that the Biogons were not going to do well on digital sensors I wish they would have updated the line. I don't shoot digital, so doesn't matter to me, but still.

Regarding the 35/2, I saw someone put it this way...the 2.0 aperture pushes the design a bit further than it's able to go. The lens is good, has a nice rendering, good contrast, but is just not super sharp wide open. The performance was not very different from my Nikon 35/2D. They're both fine serviceable lenses, but Zeiss charges a premium. I think this is backed up by the current Voigtlander 35/2, which is a spectacular lens for half or less than what Zeiss is/was asking. With the Distagon, it outperforms the Summilux so it makes sense that it's expensive and over-sized. The Biogon 2.0 is just pretty good.

It's just a bit puzzling because they made the excellent 35/2.8 and for Contax G they had a 35/2 Planar, which by all accounts is also excellent.

 

[warden]

How are the ZM lenses, such as the 21/2.8 or 4.5, holding up against newer Voigtalnder lenses such as the 3.5 Skopar or 1.8? It seems like Zeiss has walked away from the M line after the 35/1.4, and CV is producing some really great optics now. Just wondering if the Biogons on film still have something to offer over the Ultron or Color Skopar?

In SLR'ville, I used the Distagon and felt like it was really good...so I have always wanted to try the Biogons.

From personal experience I can say the 35/2 felt a bit underwhelming...but the 28/2.8 was stunningly good.

Both of the zm 35mm lenses were excellent as far as I could tell. I bought them both and tested them as accurately as I could and decided to keep the 2.8, but only due to its smaller size. The extra speed of the 2.0 was nice but not all that important to me.

I can’t speak to the other brands because I ended up sticking with zm lenses and have been satisfied with them (aside from one that is clearly developing the wobble that people complain about). It’ll need servicing, which is unfortunate but I love the lens so will send it off when the time comes.

 

[etn]

They did develop a very good line of lenses for film, but as soon as it became apparent that the Biogons were not going to do well on digital sensors I wish they would have updated the line. I don't shoot digital, so doesn't matter to me, but still.

Regarding the 35/2, I saw someone put it this way...the 2.0 aperture pushes the design a bit further than it's able to go. The lens is good, has a nice rendering, good contrast, but is just not super sharp wide open. The performance was not very different from my Nikon 35/2D. They're both fine serviceable lenses, but Zeiss charges a premium. I think this is backed up by the current Voigtlander 35/2, which is a spectacular lens for half or less than what Zeiss is/was asking. With the Distagon, it outperforms the Summilux so it makes sense that it's expensive and over-sized. The Biogon 2.0 is just pretty good.

It's just a bit puzzling because they made the excellent 35/2.8 and for Contax G they had a 35/2 Planar, which by all accounts is also excellent.

Agree with you.

About your 1st point, maybe they just pulled out of the ZM lens because they did not have a digital body to mount them on? Although they must be aware that many are using adapted ZM lenses on mirrorless digital cameras (e.g. Sony etc.), let alone Leica digital. (But I'd wager that if someone has the cash for an $8,000 Leica digital body, she or he can also go the full way with Leica lenses)

About the 35/2, do you know how it compares at 2.8 with the 35/2.8?

 

[warden]

Agree with you.

About your 1st point, maybe they just pulled out of the ZM lens because they did not have a digital body to mount them on? Although they must be aware that many are using adapted ZM lenses on mirrorless digital cameras (e.g. Sony etc.), let alone Leica digital. (But I'd wager that if someone has the cash for an $8,000 Leica digital body, she or he can also go the full way with Leica lenses)

About the 35/2, do you know how it compares at 2.8 with the 35/2.8?

I can upload a few images later today if you'd like to see them. There is no practical difference that I can appreciate, at least with black and white film. Color might be another story but I don't shoot color so I didn't try that.

 

[etn]

I can upload a few images later today if you'd like to see them. There is no practical difference that I can appreciate, at least with black and white film. Color might be another story but I don't shoot color so I didn't try that.

That would be great, thank you!

 

[NortheastPhotographic]

Agree with you.

About your 1st point, maybe they just pulled out of the ZM lens because they did not have a digital body to mount them on? Although they must be aware that many are using adapted ZM lenses on mirrorless digital cameras (e.g. Sony etc.), let alone Leica digital. (But I'd wager that if someone has the cash for an $8,000 Leica digital body, she or he can also go the full way with Leica lenses)

About the 35/2, do you know how it compares at 2.8 with the 35/2.8?

Only by reputation I have heard that the 2.8 is better even with both at 2.8 but it's probably really splitting hairs. I think you get the 2.8 if you just want a smaller lens, which it is. I almost always opt for faster because with film, when you need it you need it.

 

[Arthurwg]

Ken much prefers the Zeiss.

 

[warden]

Here are a few comparisons of the ZM 35mm lenses (f2.0 and f2.8 versions).

All these are shot at f2.8. It's not too hard to tell which is which but the difference is so minor that it doesn't matter to me personally.

Zeiss Ikon, TMax 400, tripod, camera meter, Nikon Coolscan

(sorry to the OP for the digression)

 

[Mark J]

One factor I really appreciate at Zeiss is that they publish the MTF data of their lenses from real life tests. Really measured data of produced lenses.
Not like other manufacturers who only publish idealised theoretical data.

ZEISS ZM Lenses | When you go your own way

www.zeiss.com

https://www.zeiss.com/content/dam/consumer-products/downloads/photography/datasheets/en/zm-lenses/datasheet-zeiss-zm-biogon-2821-en.pdf

Henning

Well Henning ... with respect , I don't know why you would think the Zeiss datasheet is a toleranced, real-world MTF estimate ?
It's a 'nominal' MTF analysis from the design, like all other manufacturers do. It is at least diffraction-based, unlike some of the early Canon ones which were geometric MTF.
I should know, I was a lens designer in Oberkochen in 1997/8 . There is a standard command you use in the in-house Zeiss 'OASE' software that prints out all the information for the datasheet, when you have finished the design. I used it on the 300/2.8 TSA !

But for the OP I would say the ZM 21/2.8 is an excellent design even today. I will leave it to others with hands-on experience to talk about any subtle differences to other modern lenses.

 

[etn]

Only by reputation I have heard that the 2.8 is better even with both at 2.8 but it's probably really splitting hairs. I think you get the 2.8 if you just want a smaller lens, which it is. I almost always opt for faster because with film, when you need it you need it.

Indeed. In my case I went for the Voigtlander Classic -single coated even!- for a smaller lens (about the size of the ZM 35 2.8), with the advantage of a different character than the Zeiss. Let me know if you want to see some pics, although I did not do comparison shots between the ZM and the Voigtlander. (will create a new thread)

Here are a few comparisons of the ZM 35mm lenses (f2.0 and f2.8 versions).

All these are shot at f2.8. It's not too hard to tell which is which but the difference is so minor that it doesn't matter to me personally.

Thanks for these! Indeed little enough difference.

From my side too, sorry OP for the digression, let's go back on track.

 

[warden]

Thanks for these! Indeed little enough difference.

From my side too, sorry OP for the digression, let's go back on track.

btw I totally forgot the other good reason for choice here. The 2.0 has almost no distortion, so if you like architecture the 2.0 is your lens. You might already know this but I thought I'd point it out in case you haven't seen the mtf charts.

 

[warden]

Well Henning ... with respect , I don't know why you would think the Zeiss datasheet is a toleranced, real-world MTF estimate ?

Zeiss claims their mtf data sheets are generated from actual lenses. P33 on this doc is one example under the heading Comparability of MTF data: "Real lenses are always a little worse than the calculation of the optical design program. MTF data published by Zeiss always originates from measured lenses."

https://lenspire.zeiss.com/photo/app/uploads/2022/02/technical-article-how-to-read-mtf-curves-01.pdf

 

[NortheastPhotographic]

Indeed. In my case I went for the Voigtlander Classic -single coated even!- for a smaller lens (about the size of the ZM 35 2.8), with the advantage of a different character than the Zeiss. Let me know if you want to see some pics, although I did not do comparison shots between the ZM and the Voigtlander. (will create a new thread)


Thanks for these! Indeed little enough difference.

From my side too, sorry OP for the digression, let's go back on track.

Oh don't apologize to me. I'm always interested in discussion of M lenses that are priced for us mere mortals.

I own a perfectly good 21/1.8 Ultron but I know eventually I'm going to buy a 21/2.8 Biogon because I just have to try it.

 

[etn]

Oh don't apologize to me. I'm always interested in discussion of M lenses that are priced for us mere mortals.

I own a perfectly good 21/1.8 Ultron but I know eventually I'm going to buy a 21/2.8 Biogon because I just have to try it.

Or buy the medium format equivalent, an SWC

EDIT: If we look at the lens formulas, the Biogon of the SWC seems closer to the 21 / 4.5 ZM, not the 2.8.

 

[etn]

btw I totally forgot the other good reason for choice here. The 2.0 has almost no distortion, so if you like architecture the 2.0 is your lens. You might already know this but I thought I'd point it out in case you haven't seen the mtf charts.

Guess what, I was not aware of this fact. Thank you!

 

[Henning Serger]

Zeiss claims their mtf data sheets are generated from actual lenses. P33 on this doc is one example under the heading Comparability of MTF data: "Real lenses are always a little worse than the calculation of the optical design program. MTF data published by Zeiss always originates from measured lenses."

https://lenspire.zeiss.com/photo/app/uploads/2022/02/technical-article-how-to-read-mtf-curves-01.pdf

Exactly.
Here the quote from the original German text of the author, Dr. H. Nasse:

"MTF-Daten werden an vielen Stellen veröffentlicht, von Herstellern und inzwischen auch in vielen unabhängigen Tests. Leider muss man beim Vergleich dieser Daten sehr zurückhaltend sein, weil die Messbedingungen sehr unterschiedlich sein können. Wenn man übersieht, dass
die Ortsfrequenzen verschieden sind, ist das noch das harmloseste Problem. Ebenso können aber auch unterschiedliche spektrale Gewichtungen innerhalb des sichtbaren Lichtes einen Vergleich hinken lassen. Es gibt auch Hersteller, die sich nicht scheuen, Werte zu veröffentlichen, die über den Beugungsgrenzen liegen, also physikalisch gar nicht möglich sind.

Das verrät Ihnen, dass diese Werte nur aus dem Computer stammen und dort sogar nur schlicht geometrisch optisch, ohne Berücksichtigung der Wellennatur des Lichtes, berechnet wurden. Wenn dann die Objektive hoch korrigiert sind, kleben die Werte an der 100%-Linie.
Glauben Sie aber bitte nicht, dass diese Zahlen realistisch seien. Reale Objektive sind immer auch ein wenig schlechter als die Rechnung im optischen Designprogramm. Die von Zeiss veröffentlichten MTF-Daten stammen von gemessenen Objektiven."

Well, as some of you may know, I am running an independent, non-profit photography test lab in which I am doing tests of films, sensors, lenses, developers, photo papers etc.
It is a kind of "passionate project" by me.
And when I developed my latest, current standard film resolution test, I discussed my methodology and first test results with several experts. Because I wanted critical feedback, to identify possible weak spots in my work.
So I talked also to several Zeiss experts, including the very well reputed and honourable Dr. H. Nasse. They confirmed my test methods and results, and also ensured me, that the published MTF data of current Zeiss lenses is from measured real lenses. Zeiss uses the Zeiss K8 MTF unit for these tests (in design and in certain cases also in production).

Best regards,
Henning

 

[Henning Serger]

Oh don't apologize to me. I'm always interested in discussion of M lenses that are priced for us mere mortals.

I own a perfectly good 21/1.8 Ultron but I know eventually I'm going to buy a 21/2.8 Biogon because I just have to try it.

Mark, doing your own tests by using a lens for the purposes and applications you need is always recommended.
Expectations, assessments and tastes of photographers can differ very much, as we all know .
And if you don't like the lens after your own tests, it won't be problem to sell it without a big loss.

Best regards,
Henning