Portrait At-a-Glance Comparison (Upper Body Framing)
| Optical & Portrait Metric | Sony FE 85mm F1.4 GM II | Sony FE 135mm F1.8 GM | What It Means in Practice |
|---|---|---|---|
| Upper-Body Working Distance | 3.41 m | 5.40 m | The Sony FE 135mm F1.8 GM requires 2.0 m more room behind you for the same subject size. |
| Background Field of View (Compression) | 24° | 16° | Sony FE 135mm F1.8 GM shows a 33% narrower slice of the room behind the subject (16° vs. 24°), isolating them against a cleaner background. |
| Entrance Pupil Diameter | 60.7 mm (f/1.4) | 75.0 mm (f/1.8) | Distant background blur discs are 24% larger on the Sony FE 135mm F1.8 GM. |
| Corner Bokeh Roundness (90% Field) | 67% (-0.6 EV) | 61% (-0.9 EV) | Sony FE 85mm F1.4 GM II keeps significantly rounder bokeh balls into the corners wide open (67% vs. 61% roundness). |
| Effective Focal Length (Breathing) | 83.0 mm (-2.4%) | 130.8 mm (-3.1%) | Sony FE 85mm F1.4 GM II frames like 83.0 mm (-2.4%) at 3.4 m; Sony FE 135mm F1.8 GM frames like 130.8 mm (-3.1%) at 5.4 m. |
| Depth of Field (Sharp Zone) | 20 cm (3.31 m – 3.51 m) | 25 cm (5.28 m – 5.53 m) | The Sony FE 85mm F1.4 GM II has a 22% thinner focus zone (20 cm vs. 25 cm)—requiring more precise eye focus. |
| Minimum Focus Distance | 0.85 m | 0.7 m | Sony FE 135mm F1.8 GM focuses 15 cm closer (0.85 m vs. 0.7 m) for tighter close-ups. |