Portrait At-a-Glance Comparison (Upper Body Framing)
| Optical & Portrait Metric | Sony FE 85mm f/1.8 | 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) | 23° | 16° | Sony FE 135mm F1.8 GM shows a 30% narrower slice of the room behind the subject (16° vs. 23°), isolating them against a cleaner background. |
| Entrance Pupil Diameter | 47.2 mm (f/1.8) | 75.0 mm (f/1.8) | Distant background blur discs are 59% larger on the Sony FE 135mm F1.8 GM. |
| Corner Bokeh Roundness (90% Field) | 58% (-1.0 EV) | 61% (-0.9 EV) | Similar corner bokeh shape wide open (58% vs. 61% roundness at 90% field). |
| Effective Focal Length (Breathing) | 89.9 mm (+5.8%) | 130.8 mm (-3.1%) | Sony FE 85mm f/1.8 frames like 89.9 mm (+5.8%) 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) | 25 cm (3.29 m – 3.54 m) | 25 cm (5.28 m – 5.53 m) | Both lenses deliver the exact same 25 cm sharp focus zone. |
| Minimum Focus Distance | 0.8 m | 0.7 m | Sony FE 135mm F1.8 GM focuses 10 cm closer (0.8 m vs. 0.7 m) for tighter close-ups. |