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Zeiss ZM 25mm f/2.8 Biogon T*

Last updated February 15, 2010 - Send Feedback

The Zeiss ZM 25mm f/2.8 Biogon (about $1340) is a relatively inexpensive compared to the Leica alternatives, but a very strong performer and thus a terrific value.

Composing with the 25/2.8 Biogon mandates use of the optional 25/28mm ZI viewfinder, same need as for any other lens wider than 28mm. The rectangular lens hood is also advised.

View near real-time pricing and availability for Zeiss ZM an Leica M lenses on the Leica M gear page.


I found it very easy to focus the ZM 25/2.8 accurately using the rangefinder.

Image quality

Performance is very crisp and contrasty, with richly saturated color and excellent detail across most of the frame, even wide open. Stopping down to f/5.6 yields oustanding results.


Setting M9 Lens Detection to 24/2.8 ASPH setting yields well-corrected vignetting and excellent color uniformity— see the examples in my Leica M9 review.

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Aperture ring

As with the other ZM lenses, the 1/3 stop click stops feel fantastic, and they are easy to see. I love this aspect of the ZM line, and it’s practical too: it allows fine-tuning exposure to 1/3 stop, something that can be of use with digital (“expose to the right”). The slight clicks they make offer excellent auditory and tactile feedback.


Focus first, then compose with the hot-shoe mounted viewfinder. Or vice versa. Such is life with the Leica M9/M8/M and any lens wider than 28mm. It is relatively easy to frame things accurately with the viewfinder.


The ergonomics are excellent, setting aside the need for a separate viewfinder, which is mandatory for any lens wider than 28mm on the Leica M9. I really liked using this lens.

The lens hood is rectangular and makes the lens look larger than without, but it’s an effective hood, and worth using unless space is really at a premium. The 25mm lens hood also works with the 21mm ZM lenses.

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Per Zeiss. See the datasheet.

Zeiss ZM 25mm f/2.8 Biogon
Focal length: 25mm
Aperture scale: f/2.8 - f/22
Focusing range: 0.5m - infinity
Angular field, diag./horiz./vert 82/72/52 °
Coverage at close range: 43 cm x 65 cm
Image ratio at close range:            1:18
Number of elements/groups: 9 elements in 7 groups
Filter thread: M 46 x 0.75
Weight: 260g
Dimensions (with caps): ø 53 mm, length 71 mm


The barrel distortion of the 25/2.8 Biogon is very low for a 25mm lens.

Distortion of the Zeiss ZM 25/2.8 Biogon
Distortion of the Zeiss ZM 25/2.8 Biogon


Highly recommended. This is a very nice focal length that is still easy to work with.

Please see in the high-res examples in my Guide to Leica.


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