Interactive 3D portrait ray-traced through the published US20250389929A1 optical prescription (16 elements in 11 groups, 3 aspherical) with a 14.3 mm entrance pupil and 0.2 m minimum focus.
Les liens eBay peuvent nous rapporter une commission, sans coût supplémentaire pour vous.
Objectifs correspondants de chaque marque, plus quelques classiques de moyen et grand format. Écrivez-moi si quelque chose est faux ou manque.
| Optical & Portrait Metric | Measured / Patent Value | What It Means in Practice |
|---|---|---|
| Patent Prescription | US20250389929A1 · 16 elements in 11 groups (3 aspherical) | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 14.3 mm (at f/1.4) | Controls distant background blur disc size |
| Upper-Body Working Distance | 0.84 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 18.6 mm (-6.9%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 22 cm (74 cm – 96 cm) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 0.2 m | Closest focusing distance from the sensor |
Wide open at f/1.4, the Canon RF 20mm F1.4 L VCM has a 14.3 mm entrance pupil (20 mm ÷ 1.4). In an upper-body portrait at 0.84 m, the sharp depth-of-field zone spans 22 cm (74 cm to 96 cm), while mechanical vignetting and 16 glass elements shape the out-of-focus highlights.
Based on patent US20250389929A1, tracing the focusing group at 0.84 m gives an effective framing focal length of 18.6 mm (-6.9% vs. the nominal 20 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
The patent prescription (US20250389929A1) specifies 16 lens elements in 11 groups with 3 aspherical surfaces. The interactive Optical X-Ray above traces rays through every surface in real time.
Voir aussi: profondeur de champ, bokeh, facteur de recadrage, compression.
