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Interactive 3D portrait ray-traced through the published CN 211955965 U optical prescription (10 elements in 9 groups) with a 40.0 mm entrance pupil and 1.5 m minimum focus.
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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 | CN 211955965 U · 10 elements in 9 groups | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 40.0 mm (at f/1.4) | Controls distant background blur disc size |
| Corner Bokeh Roundness (90% Field) | 58% at f/1.4 (≥86% from f/2.8) · -0.9 EV | Mechanical vignetting (cat’s-eye vs. round corner highlights) |
| Background Field of View (Compression) | 25° horizontal | Width of the background room visible behind the subject |
| Upper-Body Working Distance | 3.42 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 54.0 mm (-3.5%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 30 cm (3.28 m – 3.58 m) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 1.5 m | Closest focusing distance from the sensor |
Wide open at f/1.4, the Viltrox AF 56mm f/1.4 has a 40.0 mm entrance pupil (56 mm ÷ 1.4) and 58% bokeh roundness in the 90% corner (-0.9 EV corner falloff, reaching ≥86% roundness from f/2.8). In an upper-body portrait at 3.42 m, the sharp depth-of-field zone spans 30 cm (3.28 m to 3.58 m) with a 25° horizontal background angle of view.
Based on patent CN 211955965 U, tracing the focusing group at 3.42 m gives an effective framing focal length of 54.0 mm (-3.5% vs. the nominal 56 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
The patent prescription (CN 211955965 U) specifies 10 lens elements in 9 groups. The interactive Optical X-Ray above traces rays through every surface in real time.
Also see: depth of field, bokeh, crop factor, lens compression.