Zeiss C-Biogon 35mm f/2.8 ZM

Zeiss C-Biogon 35mm

If I had to pick one of the most enigmatic lenses in the Leica M mount ecosystem, it would have to be this little gem: the Zeiss C-Biogon 35mm f/2.8. A lot of rangefinder shooters that are familiar with this lens will claim it as the sharpest 35mm lens you can get on the Leica M mount while others may say that they prefer the bigger (and faster) Zeiss Biogon 35mm f/2. Despite its relatively slower lens dilation compared to its bigger brother, I would still recommended the tiny C-Biogon over any other 35mm lens for those looking for a compact powerhouse. However, with the recent introduction of the Voigtlander Ultron 35mm f/2 in the past year, does this lens still relevant in the current crop of excellent sub-$1000 35mm lenses?

In this review, we’ll go over why this lens is still relevant today in 2020 and despite it’s slower f/2.8 aperture, why the Zeiss C-Biogon 35mm is still a contender and should be considered in your camera bag.

Zeiss C-Biogon 35mm
Compact Size


Zeiss’ optical formula for the Biogon series of lenses are some of the oldest designs in the history of optics, dating back to 1934 by the famed designer Ludwig Bertele, designed specifically for wide-angle lenses like the 35mm. While the Biogon formula itself can have different variations of designs, what they do have in common is that they’re almost always wide-angles. The largely symmetrical Biogon optical design affords the lens to stay relatively compact, which is difficult to do considering most wide-angle lenses are large by design.


Zeiss C-Biogon 35mm

Zeiss C-Biogon 35mm f/2.8 ZM

This is a very small 35mm lens for M-mount rangefinder and definitely one of the smallest aspherical 35mm lenses you can buy for the M mount as it’s smaller than the Summicron ASPH. Despite being priced on the budget end compared to its faster siblings, it still retains the same build quality and wait for it, probably the sharpest of all of Zeiss’ ZM catalog of lenses.

Compact Powerhouse

When you first handle this lens in your hands, you can tell that it still follows the same German engineering philosophy: you do not question the basic values, but try to improve on the existing systems and do this on the highest possible level. This philosophy shows on Leica M mount lenses and the Zeiss is no exception. The solid build quality with its finely machined aluminum body, the aperture ring that click with authority every 1/3 stop and beautifully smooth focus throws.

“Improving on a 35mm lens design with modest aperture would not be considered a worthy goal for Japanese optical companies that focus on innovative specifications. But German engineering is focused on precision, top quality and merit to be injected in proven designs.“ -Erwin Puts

Zeiss C-Biogon 35mm
Finely machined ribs

Build & Design

The overall looks and feel of the Zeiss C-Biogon 35mm is similar to what you would get from other ZM lenses: excellent build quality and minimalistic lines, with a subtle focusing nub to keep the overall design aesthetics tidy. It’s a gorgeous little lens regardless if you get the silver or black, but I wished the brass hood mount matched the black body instead of the default chrome.

The subtle details you’ll find like the chromed brass lens mount, the laser etched cuts on knurling all around and the clearly defined numbers give you a sense of quality made, precision product that you would expect from a German company.

Solid Clicks

Looking through the glass, you can see 10 aperture blades as you click through the aperture ring with its solid clicks and excellent machined grips on the sides of the ring. While I love the overall clicky feel, the ring feels hollow between each click as you can feel the lock up reverberate throughout the body of the lens. It’s not a cheap feeling or anything, but it definitely doesn’t feel as refined or dampened like the comparable Leica equivalent. It’s the same feeling as you would get from a Voigtlander lens, as it feels tactile but there is really no weight behind those aperture clicks.

If I can attempt to explain this as an analogy, the Zeiss feels like a ratchet wrench while the Leica feels like a torque wrench. The ratchet wrench has a resistance controlled by a single metal switch inside that clicks against the teeth of the gear inside, while the more complicated torque wrench has a more dampened feedback.

It’s smooth and the clicks have a very deliberate feel which give a satisfying sense of tactile feel and control, which anyone can appreciate.

Smooth as Butter

The focus ring is smooth – smoother (and shorter) than most of the Leica lenses I’ve used, especially the floating lens elements (FLE) Leica lenses as they exhibit rough spots due to their optical design. That was something I really didn’t like about the Summilux-M 35mm FLE (11663), one of the many reasons why I prefer the handling of the Summicron lenses over the Summilux. It has a very nice dampened, yet weighted feel that I really like.


The focusing nub on the Zeiss C-Biogon 35mm is nothing new as all ZM lenses have this same design. I’m personally not the biggest fan of this design as I find it just as easy to lose track of your focus because the tab is too subdued to feel for it, especially with gloves on. I’ll even say that it’s worst than the Voigtlander Ultron 35mm’s pinhead design, but your miles may vary. It’s more of a comfort issue rather than a grip issue.

Zeiss C-Biogon 35mm
Focusing Nub and Aperture Ring

Image Quality

I’m going to put this out there right away.

The Zeiss C-Biogon 35mm is the sharpest 35mm lens I have ever used. Full stop.

I will also add that this lens is a technically perfect lens with very little chromatic aberrations, low distortion and no flaring. Faster and more expensive lenses can’t touch the C-Biogon in these regards. With its compact size and weight, you can’t get any sharper than this while at the absolute limits of its size. It’s literally the Hattori Hanzo of 35mm lenses, especially stopped down – so sharp that it cuts the edges of your subject.

Modern Looks

The lens renders a very clean, modern output with loads of contrast which is favorable for film shooter that want a bit more punch to their film images. The out of focus or the bokeh is smooth and not distracting, which is rare for a “slower” lens and while it’s not as pleasing as the Leica Summicron, it holds it own and worth a look if you desire a compact lens.

f/4 | 1/45 | ISO 640

Ideal for Landscape Travelers

If you’re a travel photographer that love the 35mm focal length, compact size and occasionally shoot landscapes, there is no other lens I recommend more than the Zeiss C-Biogon 35mm. Zeiss was able to pack 7 elements into this tiny lens where it’s typical for most lenses this size to use only 5 elements. It’s an impressive technical achievement, but this also the C-Biogon’s double-edged sword. While the overall image quality is second to none, its rendering is somewhat clinical and if you’re someone that prefer some “flaws” in your images, this lens is not for you.

f/2 | 1/3000 | ISO 200

Cool to the Eyes

Another inherent attribute of Zeiss lenses is that they’re known to render more on the cooler side compared to Leica and Voigtlander lenses. It’s mostly due to the T* coatings and with digital cameras, give the images a more contrasty look. Therefore I recommend this for film shooters as it will give their images a bit more pop.

Speaking of pop, the micro-contrast that you get from this lens is excellent and something you would expect from a Zeiss lens. Plenty of tonality from your subject, that give the subject a subtle three dimensional pop. It’s subtle, but it’s there with the right lighting conditions, but no where near as obvious as the Zeiss Distagon 35mm f/1.4 ZM from what I’ve seen.

f/9.5 | 1/125 | ISO 200

User Experience

The compact body of the C-Biogon give the Leica M user the benefit of a subtle and lightweight kit, that you can confidently carry as your only lens. The balance is fantastic and it’s overall short length doesn’t block the viewfinder at all, unless you opt for the optional lens hood.

Tiny to a Fault

When you bring the camera up to your eyes to take a shot, you’ll immediately notice the downfall of the focusing nub, especially if you’re spoiled by the focusing tab from both Leica and Voigtlander equivalents. Your left hand will feel a little cramped as you’re trying to focus while half of your fingers are cupping the body and the lens, something that people with bigger mitts will not be fond of.

Smooth Operator

When you use your thumb and your index finger (or your middle finger) to focus, you will immediately feel the buttery smooth throws on the focus ring as there is very little over-travel or stiffness. I’m not sure what it is about Zeiss and Voigtlander lenses, but their focus throws have been more consistent over longer periods of time than the Leica equivalents. I believe it may have to do something with the lubricants that they use for the helicoid, but I love how the C-Biogon feels between your focusing fingers.

Zeiss C-Biogon 35mm
Superb Build Quality

In Summary

The Zeiss C-Biogon 35mm f/2.8 is a special lens as it’s compact size, incredible performance and build quality leaves its mark among Leica M enthusiasts as one of the top picks among its other rivals, like the Summarit-M 35mm and even the Summicron. The lens produces some of the sharpest images I’ve ever seen and even wide open, the corners perform at another level you won’t see anywhere else and it only gets better when you stop it down to f/4. Like a small body builder flexing his arms just a bit more to show off muscle you didn’t know existed, sort of like, “wait until you see what I can do.”

To pair with some of the amazing praises this lens had received, it also has some nagging issues. One of the issues I have with this lens is that the lens hood is optional. For a lens that costs over $900 new, I’m disappointed that the expensive metal round lens hood doesn’t come with the lens as standard. You can cushion some of the cost impact on your wallet by going for the cheaper Voigtlander LH-6 hood, as they’re exactly the same lens hood, but without the Zeiss tax added to it.

The odd 43mm filter size is also annoying, especially to those Leica owners that probably have a small collection of 39mm or 46mm filters of varying variety.

Other than these minor issues, the Zeiss C-Biogon is probably the best “do it all” lens in terms of weight, size and performance – but only if the slower f/2.8 doesn’t bother you. For example:

  • The Zeiss C-Biogon 35mm offers the perfect balance of size and weight relative to its high performance.
  • Build quality is excellent as expected from Zeiss and Cosina. I also prefer the overall lens aesthetic over the Voigtlander Ultron.
  • It is technically sharper than both the Summicron and the Ultron, almost clinically perfect.

I personally feel as though this is a great compact travel lens if you just want a one lens kit. For those of you that never had the chance to use this lens, I feel that it’s criminally underrated when everyone gets myopic on the more glamorous Leica offerings as this lens hangs (and beats) what the people at Wetzlar has to offer. If you’re like me and prefer a more minimalistic approach to gear, you’ll be hard pressed to find something as perfect as the C-Biogon.

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