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Canon RF 100mm F2.8 L MACRO IS USM — Bokeh & Optical Ray-Tracing Simulator
Interactive 3D portrait ray-traced through the published JP2021-047297A optical prescription (17 elements in 13 groups) with a 35.7 mm entrance pupil and 0.26 m minimum focus.
Optical & Portrait Specifications (Upper Body Framing)
| Optical & Portrait Metric | Measured / Patent Value | What It Means in Practice |
|---|---|---|
| Patent Prescription | JP2021-047297A · 17 elements in 13 groups | Traced surface by surface in WebGL2 |
| Entrance Pupil Diameter | 35.7 mm (at f/2.8) | Controls distant background blur disc size |
| Upper-Body Working Distance | 4.01 m | Camera-to-subject distance for head-to-waist framing |
| Effective Focal Length (Breathing) | 97.6 mm (-2.4%) | Actual framing focal length at portrait distance |
| Depth of Field (Sharp Zone) | 39 cm (3.82 m – 4.21 m) | Sharp zone at wide-open aperture |
| Minimum Focus Distance | 0.26 m | Closest focusing distance from the sensor |
Questions
How much background blur does the Canon RF 100mm F2.8 L MACRO IS USM produce?
Wide open at f/2.8, the Canon RF 100mm F2.8 L MACRO IS USM has a 35.7 mm entrance pupil (100 mm ÷ 2.8). In an upper-body portrait at 4.01 m, the sharp depth-of-field zone spans 39 cm (3.82 m to 4.21 m), while mechanical vignetting and 17 glass elements shape the out-of-focus highlights.
Does the Canon RF 100mm F2.8 L MACRO IS USM show focus breathing at portrait distance?
Based on patent JP2021-047297A, tracing the focusing group at 4.01 m gives an effective framing focal length of 97.6 mm (-2.4% vs. the nominal 100 mm). You can toggle "Match subject size" in the simulator to see the framing shift live.
What optical design is inside the Canon RF 100mm F2.8 L MACRO IS USM?
The patent prescription (JP2021-047297A) specifies 17 lens elements in 13 groups. The interactive Optical X-Ray above traces rays through every surface in real time.
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Also see: depth of field, bokeh, crop factor, lens compression.