Leica 35mm f/1.4 Summilux M – Technical Information

Manufacturer: Leica (Germany & Canada)
This lens was designed by Walter Mandler
Optics: 7 elements in 5 groups
Aperture range: f/1.4 to f/16
Number of aperture blades: 10
Filter:  Series 7 (held in place by the hood)
Overall Length:
Maximum Outer Diameter: 46.5mm
Weight: about 245g (black version, without caps)
Recommended Format Size: 24 X 36 mm
Minimum Image Field: 630mm x 950mm
Optical data (with lens focused at infinity):
Effective Focal Length:
Field of View: 64 degrees
Shortest Image Distance:
Lens code number: 11870 (black) 11860 (titanium) 11871 (M3  type with ‘spectacles’)
Lens hood code number: 12504 12526
Front lens cap code number:
Total produced: ~28,000

Leica 35mm f/1.4 Summilux M – In Use

This is one of the ‘classic’ Leica lenses and still has its aficionados. When it was originally built it was a groundbreaking design, so much so that even today, removing the constraints of glass types available at the time of design, it cannot be bettered*. Which is an extraordinary feat given that computerised optical design was in its infancy and that the design was primarily a double gaussian derivative based on a great deal of optical experience and understanding. Whilst its performance wide open was never wondrous and has been surpassed by more modern designs, it remains a remarkably diminutive optic and is still much smaller than the more recent aspheric designs which outclass its performance.

Ergonomics are fine – for its size. I use a version without an infinity lock (more collectable) but which I prefer anyway. So focus operates well from the tab whilst the aperture has two ‘wings’ which allow its alteration readily enough. It has no front filter thread, instead a Series 7 filter sits inside the two-piece screw together hood. This works well enough an an E49 filter can be used there if necessary. Performance is interesting. Wide-open it suffers from a variety of problems and is never particularly sharp. By f/2-2.8 things improve and do so until they drop off again a little well stopped down. At mid-apertures the lens still give good account of itself although it is surpassed by the latest aspheric designs. As with many of Mandler’s designs, the mid-aperture detail is never harsh and the lens provides a smooth tonality which is pleasing, whilst still retaining fine detail. Given its size this is still a very usable lens, although perhaps rather less so at full aperture.


* “Double Gauss lens design: a review of some classics” Jonas & Thorpe (of Elcan). Quote: “9. Re-optimising the Summilux 35mm f/1.4. – It appears that this simple double Gauss design cannot give improved performance given the field and aperture constraints even with additional glass choices”.