Leica 75mm f/2 APO-Summicron-M ASPH
Related: apochromatic, depth of field, distortion, git, Leica, Leica 75mm f/2 APO-Summicron-M ASPH, Leica M, optics
The Leica 75mm f/2 APO-Summicron-M ASPH (about $3395) is an ultra-compact 75mm lens for Leica M with an aspheric design and special exotic glass used to minimize color aberrations, and a floating element for close-up quality.
It is a defensible claim to suggest that the 75/2 could be among the very best lenses available for Leica M, and as a practical matter the longer focal length is better suited to the Leica M9’s full-frame digital sensor: vignetting and color shift are absolutely minimal. That is if you can focus it accurately, a topic I discuss in my Leica M9 review in DAP.
View near real-time pricing and availability for Zeiss ZM an Leica M lenses on the Leica M gear page.
Very nice! This lens fits my hands very well. The placement of aperture ring and focus ring is very friendly for quick use. It's a joy to use, both in terms of size, as well as the pull-out locking lens shade.
Though compact, it is remarkably heavy at 430 grams, being made of glass and metal. But that extra mass is helpful in balancing and steadying the Leica M9.
Half-stop click-stops are marked in full stops. I’d prefer the 1/3 stops with each marked of the Zeiss ZM line (especially on digital), but 1/2 stops suffice.
The need to recover from a case of pink eye has delayed my ability to focus the M9 with the 75/2 accurately. TBD.
However, usage so far proves that my extensive discussion on focus accuracy in my Guide to Leica is spot-on: your results with the 75/2 will depend 90% on your ability to focus it to achieve critical sharpness.
I consider 75mm the practical limit for Leica M photography because of this issue, with 50mm a more conservative bound for those who demand critical sharpness consistently.
For more on focusing in general, see Focusing Issues.
The viewfinder frame lines in the Leica M9 for 75mm frame a small area. This is a “pleasure factor” issue with a rangefinder that makes 75mm less satisfying than with a 35mm or 50mm lens, but one can adapt of course.
Accurate composition is a challenge, and will require considerable experience to account for the frame-line error, which changes as the focus is varied from near to far. I solve this problem by shooting multiple frames until I get what I was after— a ridiculous requirement, but one peculiar to all rangefinders. Experience brings relief via mental adjustment of where the image actually falls relative to the frame lines.
It’s a pity that no Live View functionality is available on the Leica M9 to resolve both of these anachronisms. Perhaps a future M digital camera will bring that capability.
Distortion is moderate, with pincushion distortion beginning about half-way between center and edges. Such distortion is noticeable on an even horizon (eg an ocean or range of hills) or a man-made structure with straight edges. It could also be an issue with faces near frame-edges or corners. I find pincushion distortion less visually acceptable than barrel distortion, but pincushion is typical for lenses in this focal length range, and all lenses have compromises.
Leica 75mm f/2 APO-Summicron-M ASPH specifications Permalink
Of not here is the 1:7 reproduction ratio, which means that a tight head shot (portrait) is possible.
|Focusing range:||0.7m to infinity|
|Smallest object field:||169 X 254mm = 1:7 reproduction ratio|
|Entrance pupil:||30.1mm from front lens surface|
|Item Angle of view||32°, 18°, 27°|
|Diaphragm:||Preset with click-stops and half-values, f/16 minimum aperture|
|Filter type:||Internal thread for 49mm screw-on filters|
|Lens hood:||built-in, telescopic, lockable|
|Dimensions||66.8mm long X 58mm diameter|
Image quality Permalink
The MTF charts suggest “wave” field curvature, which means that the 75/2 APO-Summicron-M will not produce the same crisp results edge-to-edge on a flat (planar) target. Particularly at f/2 and f/2.8, this could be of some concern on high resolution digital (Leica M9).
Few lenses perform at this high level. On can criticize a slight loss of detail from astigmatism in the far corners, but this is modest. Stopping down to f/8 will address the astigmatism adequately (by virtue of depth of field), if top corner performance is demanded.
Performance at f/2 should already be considered excellent, but with substantial improvements gained by stopping down to f/2.8; the difference speaks to the contrast of fine detail, very important for high resolution digital.
Performance at f/5.6 is outstanding. Stopping down from f/2.8 to f/5.6 shows very modest benefit, but the doubling of depth of field achieved by so doing helps mitigate both focus error and field curvature issues, so unless background blur is desired, prefer f/5.6 as a practical aperture yielding optimal results in every respect (except more depth of field).
Mouse over the graphs to compare apertures. Peak results will be achieved at f/5.6 (higher lines). Stopping down to f/8 and smaller will steadily reduce brilliance and contrast due to diffraction.
Outstanding image quality. Numerous high-res examples are shown in Guide to Leica, along with commentary.