A modern interpretation of Biogon: BIOGON 35ZM
Cosina/Zeiss M-mount wide-angle lens, Biogon ZM 35mm / F2 review and photo examples
Table of contents
Gallery
- For this example, a Rollei 35RF camera was used and Fujifilm SensiaIII 100 (reversal film) and KODAK Kodachrme 64 (KR64) film were used.
Review
1．Overview
The Biogon 35mm F2 ZM is a Carl Zeiss-branded lens manufactured by Cosina that was released in 2005.
The main specifications are as follows, and detailed specifications are listed in the table.
- Lens construction: 9 elements in 6 groups
- Aperture blades: 10
- Aperture click stops: Every 1/3
- Minimum focusing distance: 0.7m
- Linked with Leica M-type rangefinder rangefinder over the entire range
- Hood: Bayonet hood sold separately
The CONTAX G Planar 35mm F2, released by Kyocera Contax in 1996 under the same CARL ZEISS brand, also uses a planar lens. I compared the lens configurations based on the specifications.
2．Usage
The CARL ZEISS BIOGON 35mm F2 ZM is housed in a metal barrel, and is compact but heavy.
It fully meets the standards of image quality required of modern lenses, and thanks to Cosina’s latest design and advanced lens coatings, there is no mysterious light or loss of contrast even in backlight.
The weight balance is good when attached to rangefinder cameras such as the Zeiss Ikon and HEXAR RF, and there are no problems with the operability of the focus ring and aperture ring.
When attached to the EPSON R-D1, the sensor’s magnification conversion makes it a standard lens with a focal length equivalent to 50mm. Although the image quality differs, it can be used as a substitute for the Planar 50mm focal length.
The ZM Biogon 35mm has a symmetrical lens structure, but is designed with a long back focus to ensure peripheral light and to take advantage of various corrections. It is slim for a 35mm focal length for rangefinders, with a total lens length of 43mm, almost the same length as the LEICA SUMMILUX M 35mm F1.4 ASPH. (lens length 46mm).
As a result, it gives an impression of being stretched out when attached to a camera.
The wide-angle Biogon 21mm and 25mm lenses in the same ZM lens series also have a slender style, but considering the focal length, this can’t be helped. However, the Biogon ZM 28mm, which was released later, has a compact lens barrel while still maintaining the symmetrical shape of the lens structure, so I wish the Biogon ZM 35mm had been designed with a little more ingenuity.
Perhaps not as a result of reflection on that experience, the 21mm and 35mm lenses of the later released ZM C series had shorter lens lengths and a more compact overall style, making them lenses that suited compact rangefinder cameras.
3．Summary
To sum up the CARL ZEISS BIOGON 35mm F2 ZM, the lens is well-made overall and its modern, sharp images are also suitable for digital cameras.
There are many options for 35mm rangefinder lenses, so the impression you get when attached to your camera will directly affect how often you will use the lens, so whether the slender, long appearance of the lens matches your camera will be one factor in deciding whether to own a lens.
Specification and Competition Lenes
The Planar 35mm uses a planar (double Gauss type) lens configuration, which is different from the modern Biogon of the BIOGON 35mm ZM, so the lens size is also significantly different. In terms of image quality, the Planar produces a softer image than the sharp modern Biogon, so the direction of depiction is also different.
- The lens construction diagrams are quoted from each company’s PDF, and the sizes have been adjusted by us, so they are not exact.
| Item | BIOGON | PLANAR |
| focal length(mm) | 35 | 35 |
| Maximum aperture | 2 | 2 |
| Minimum aperture | 22 | 16 |
| Leaf blade | 10 | 7 |
| Lens configuration | 9 elements in 6 groups | 7 elements in 5 groups |
| Minimum distance(m) | 0.7 | 0.5 |
| Lens length(mm) | 43.3 | 31.5 |
| Lens max diameter(mm) | 52 | 56 |
| Filter type | 43 | 46 |
| Weight(g) | 230 | 160 |
| Hood | Bayonet | GG-1 |
| Lens mount | ZM | CONTAX-G |
| Release date | 2005 | 1996 |
| Price | ¥95,000 | ¥47,000 |
ZM Lens list
- Distagon T✻ 15mm ƒ/2.8 (Made in Germany)
- Distagon T✻ 18mm ƒ/4
- Biogon T✻ 21mm ƒ/2.8
- C Biogon T✻ 21mm ƒ/4.5
- Biogon T✻ 25mm ƒ/2.8
- Biogon T✻ 28mm ƒ/2.8
- Distagon T✻ 35mm ƒ/1.4
- Biogon T✻ 35mm ƒ/2
- C Biogon T✻ 35mm ƒ/2.8
- C Sonnar T✻ 50mm ƒ/1.5
- Planar T✻ 50mm ƒ/2
- Tele-Tessar T✻ 85mm ƒ/4
- Sonnar T✻ 85mm ƒ/2 (Made in Germany)
Reference links
- Zeiss.com lens datasheets biogon 35mm
- Zeiss.com lens datasheets C biogon 35mm
- Zeiss.com lens datasheets Planar 35mm
Update
- 2025.3.20
- 2024.04.20:Update the article
- 2024.01.10:First draft
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