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Leica Summicron-M 28mm f/2 ASPH. — Bokeh & Optical Ray-Tracing Simulator
Interactive 3D portrait ray-traced through the published US20160266350A1 optical prescription (11 elements in 9 groups, 5 aspherical) with a 14.0 mm entrance pupil and 0.7 m minimum focus.
Optical & Portrait Specifications (Upper Body Framing)
| Optical & Portrait Metric | Measured / Patent Value | What It Means in Practice |
|---|---|---|
| Patent Prescription | US20160266350A1 · 11 elements in 9 groups (5 aspherical) | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 14.0 mm (at f/2) | Controls distant background blur disc size |
| Upper-Body Working Distance | 1.15 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 27.3 mm (-2.5%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 30 cm (1.02 m – 1.31 m) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 0.7 m | Closest focusing distance from the sensor |
Questions
How much background blur does the Leica Summicron-M 28mm f/2 ASPH. produce?
Wide open at f/2, the Leica Summicron-M 28mm f/2 ASPH. has a 14.0 mm entrance pupil (28 mm ÷ 2). In an upper-body portrait at 1.15 m, the sharp depth-of-field zone spans 30 cm (1.02 m to 1.31 m), while mechanical vignetting and 11 glass elements shape the out-of-focus highlights.
Does the Leica Summicron-M 28mm f/2 ASPH. show focus breathing at portrait distance?
Based on patent US20160266350A1, tracing the focusing group at 1.15 m gives an effective framing focal length of 27.3 mm (-2.5% vs. the nominal 28 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
What optical design is inside the Leica Summicron-M 28mm f/2 ASPH.?
The patent prescription (US20160266350A1) specifies 11 lens elements in 9 groups with 5 aspherical surfaces. The interactive Optical X-Ray above traces rays through every surface in real time.
Head-to-head patent comparisons with Leica Summicron-M 28mm f/2 ASPH.
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Also see: depth of field, bokeh, crop factor, lens compression.