Confronto ritratto a colpo d’occhio (mezzo busto)
| Optical & Portrait Metric | Leica Summilux-M 90mm f/1.5 ASPH. | Leica APO-Summicron-M 90mm f/2 ASPH. | What It Means in Practice |
|---|---|---|---|
| Upper-Body Working Distance | 3.61 m | 3.61 m | Identical working distance—both frame an upper-body portrait from the exact same spot. |
| Effective Focal Length (Breathing) | 91.5 mm (+1.7%) | 92.3 mm (+2.6%) | At 3.6 m, Leica Summilux-M 90mm f/1.5 ASPH. frames like a 91.5 mm lens while Leica APO-Summicron-M 90mm f/2 ASPH. frames like a 92.3 mm lens. |
| Depth of Field (Sharp Zone) | 21 cm (3.50 m – 3.72 m) | 28 cm (3.47 m – 3.75 m) | The Leica Summilux-M 90mm f/1.5 ASPH. has a 25% thinner focus zone (21 cm vs. 28 cm)—requiring more precise eye focus. |
| Entrance Pupil Diameter | 60.0 mm (f/1.5) | 45.0 mm (f/2) | Distant background blur discs are 33% larger on the Leica Summilux-M 90mm f/1.5 ASPH.. |
| Minimum Focus Distance | 1 m | 1 m | Both lenses share the same 1 m close-focus limit. |
| Patent Prescription | US8508864B2 (14/11) | US3076383A (5/4) | Published optical prescriptions traced in the 3D simulator above. |