What 10-18mm at f/4 actually gives you
10-18mm is wide enough to take in interiors, landscapes and architecture without the pronounced edge stretching of an ultra-wide. On the APS-C bodies it covers, it frames like 15mm would on full-frame.
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, close focus and filters
At 225g (7.9 oz) it is light enough that it stops being a decision — the kind of lens that stays on the body or in the bag without thought.
It focuses to 25cm, which is close enough to fill the frame with small subjects.
Filters are 62mm — worth checking against what you already own, since polarisers and ND filters at this size are reusable across any other lens sharing the thread.
Autofocus and stabilisation
Autofocus is driven by a Stepping motor.
Optical stabilisation is built in, which stacks with in-body stabilisation on bodies that have it and does the work alone on bodies that do not.
