Portrait At-a-Glance Comparison (Upper Body Framing)
| Optical & Portrait Metric | Sony FE 50mm F1.8 | Sony Sonnar FE 55mm F1.8 ZA | What It Means in Practice |
|---|---|---|---|
| Upper-Body Working Distance | 2.01 m | 2.21 m | The Sony Sonnar FE 55mm F1.8 ZA requires 0.2 m more room behind you for the same subject size. |
| Background Field of View (Compression) | 39° | 37° | Sony Sonnar FE 55mm F1.8 ZA shows a 5% narrower slice of the room behind the subject (37° vs. 39°), isolating them against a cleaner background. |
| Entrance Pupil Diameter | 27.8 mm (f/1.8) | 30.6 mm (f/1.8) | Distant background blur discs are 10% larger on the Sony Sonnar FE 55mm F1.8 ZA. |
| Corner Bokeh Roundness (90% Field) | 78% (-0.5 EV) | 85% (-0.3 EV) | Sony Sonnar FE 55mm F1.8 ZA keeps significantly rounder bokeh balls into the corners wide open (85% vs. 78% roundness). |
| Effective Focal Length (Breathing) | 50.8 mm (+1.7%) | 54.2 mm (-1.5%) | Sony FE 50mm F1.8 frames like 50.8 mm (+1.7%) at 2.0 m; Sony Sonnar FE 55mm F1.8 ZA frames like 54.2 mm (-1.5%) at 2.2 m. |
| Depth of Field (Sharp Zone) | 26 cm (1.89 m – 2.15 m) | 26 cm (2.09 m – 2.35 m) | Both lenses deliver the exact same 26 cm sharp focus zone. |
| Minimum Focus Distance | 0.45 m | 0.5 m | Sony FE 50mm F1.8 focuses 5 cm closer (0.45 m vs. 0.5 m) for tighter close-ups. |