Portrait At-a-Glance Comparison (Upper Body Framing)
| Optical & Portrait Metric | Canon RF 85mm F1.2 L USM | Canon RF 135mm F1.8 L IS USM | What It Means in Practice |
|---|---|---|---|
| Upper-Body Working Distance | 3.41 m | 5.40 m | The Canon RF 135mm F1.8 L IS USM requires 2.0 m more room behind you for the same subject size. |
| Background Field of View (Compression) | 23° | 15° | Canon RF 135mm F1.8 L IS USM shows a 35% narrower slice of the room behind the subject (15° vs. 23°), isolating them against a cleaner background. |
| Entrance Pupil Diameter | 70.8 mm (f/1.2) | 75.0 mm (f/1.8) | Nearly identical distant background blur size at equal framing. |
| Corner Bokeh Roundness (90% Field) | 44% (-1.3 EV) | 62% (-0.6 EV) | Canon RF 135mm F1.8 L IS USM keeps significantly rounder bokeh balls into the corners wide open (62% vs. 44% roundness). |
| Effective Focal Length (Breathing) | 88.4 mm (+4.0%) | 132.7 mm (-1.7%) | Canon RF 85mm F1.2 L USM frames like 88.4 mm (+4.0%) at 3.4 m; Canon RF 135mm F1.8 L IS USM frames like 132.7 mm (-1.7%) at 5.4 m. |
| Depth of Field (Sharp Zone) | 17 cm (3.33 m – 3.49 m) | 25 cm (5.28 m – 5.53 m) | The Canon RF 85mm F1.2 L USM has a 33% thinner focus zone (17 cm vs. 25 cm)—requiring more precise eye focus. |
| Minimum Focus Distance | 0.85 m | 0.7 m | Canon RF 135mm F1.8 L IS USM focuses 15 cm closer (0.85 m vs. 0.7 m) for tighter close-ups. |