Interactive 3D portrait ray-traced through the published JP2008-145584A optical prescription (16 elements in 11 groups) with a 100.0 mm entrance pupil and 1.9 m minimum focus.
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| Optical & Portrait Metric | Measured / Patent Value | What It Means in Practice |
|---|---|---|
| Patent Prescription | JP2008-145584A · 16 elements in 11 groups | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 100.0 mm (at f/2) | Controls distant background blur disc size |
| Upper-Body Working Distance | 8.00 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 208.6 mm (+4.3%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 28 cm (7.86 m – 8.14 m) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 1.9 m | Closest focusing distance from the sensor |
Wide open at f/2, the Canon 200mm f/2L IS USM has a 100.0 mm entrance pupil (200 mm ÷ 2). In an upper-body portrait at 8.00 m, the sharp depth-of-field zone spans 28 cm (7.86 m to 8.14 m), while mechanical vignetting and 16 glass elements shape the out-of-focus highlights.
Based on patent JP2008-145584A, tracing the focusing group at 8.00 m gives an effective framing focal length of 208.6 mm (+4.3% vs. the nominal 200 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
The patent prescription (JP2008-145584A) specifies 16 lens elements in 11 groups. The interactive Optical X-Ray above traces rays through every surface in real time.
Voir aussi: profondeur de champ, bokeh, facteur de recadrage, compression.
