What 20mm at f/1.4 actually gives you
20mm is wide enough to take in interiors, landscapes and architecture without the pronounced edge stretching of an ultra-wide.
The f/1.4 maximum aperture is about as fast as production lenses get: it gathers a lot of light and throws backgrounds well out of focus, at the cost of a depth of field thin enough that focus accuracy starts to matter on close subjects.
Size and filters
At 630g (1.39 lb) it sits in the middle for handling: substantial enough to feel planted, light enough not to dominate the kit.
Filters are 82mm — worth checking against what you already own, since polarisers and ND filters at this size are reusable across any other lens sharing the thread. A dedicated aperture ring gives direct control without going through a camera dial, which mostly matters for video work.
Autofocus, stabilisation and weather sealing
Autofocus is driven by an HLA motor.
There is no optical stabilisation in the lens, so handheld steadiness depends on the body having IBIS, or on keeping the shutter speed up.
The barrel is weather-sealed, so rain and dust are a manageable risk rather than a reason to pack up.
