What 12-24mm at f/4 actually gives you
12-24mm is wide enough to take in interiors, landscapes and architecture without the pronounced edge stretching of an ultra-wide.
f/4 is a moderate maximum aperture. There is less low-light headroom and less background blur than an f/2.8 lens gives, which is generally the trade for lower weight and cost.
Size and weight
At 565g (1.25 lb) it sits in the middle for handling: substantial enough to feel planted, light enough not to dominate the kit.
Autofocus and stabilisation
Autofocus is driven by a DDSSM 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.
