Find a lens for this look
eBay links may earn us a commission, at no extra cost to you.
Matching lenses from each maker's lineup, plus some classic medium and large format lenses. Email me if something is wrong or missing.
Interactive 3D portrait ray-traced through the published US20150268449A1 optical prescription (9 elements in 7 groups, 5 aspherical) with a 8.8 mm entrance pupil and 0.2 m minimum focus.
eBay links may earn us a commission, at no extra cost to you.
Matching lenses from each maker's lineup, plus some classic medium and large format lenses. Email me if something is wrong or missing.
| Optical & Portrait Metric | Measured / Patent Value | What It Means in Practice |
|---|---|---|
| Patent Prescription | US20150268449A1 · 9 elements in 7 groups (5 aspherical) | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 8.8 mm (at f/1.7) | Controls distant background blur disc size |
| Upper-Body Working Distance | 1.27 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 14.0 mm (-6.7%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 54 cm (1.06 m – 1.60 m) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 0.2 m | Closest focusing distance from the sensor |
Wide open at f/1.7, the Leica DG Summilux 15mm f/1.7 ASPH. has a 8.8 mm entrance pupil (15 mm ÷ 1.7). In an upper-body portrait at 1.27 m, the sharp depth-of-field zone spans 54 cm (1.06 m to 1.60 m), while mechanical vignetting and 9 glass elements shape the out-of-focus highlights.
Based on patent US20150268449A1, tracing the focusing group at 1.27 m gives an effective framing focal length of 14.0 mm (-6.7% vs. the nominal 15 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
The patent prescription (US20150268449A1) specifies 9 lens elements in 7 groups with 5 aspherical surfaces. The interactive Optical X-Ray above traces rays through every surface in real time.
Also see: depth of field, bokeh, crop factor, lens compression.