Features to look for …

Obviously size is important – but there are some other physical features to consider

Full-frame

All of the lenses we’ve tested this issue are FX-compatible, which means you can use them on full-frame cameras without resorting to crop mode, and also on any DX-format models.

Focal length

When fitted to an FX body, 35mm, 50mm and 85mm lenses work well for wide-angle, standard and short telephoto photography respectively.

DX fit

When used on a DX body, 35mm lenses give a ‘standard’ perspective (thanks to an equivalent focal length of 52.5mm), while 50mm lenses, equivalent to 75mm, work well for portraiture.

Diaphragm blades

A greater number of diaphragm blades typically helps to give a more rounded aperture, which can boost the quality of the bokeh (see box, below).

Filter thread

The attachment thread size of the lenses on test ranges from 58mm to 77mm. None of them has a front element that rotates during focusing, so it’s easier to use circular polarisers and ND grads.

Autofocus

The two Samyang lenses in the group can only be focused manually. All the others have quiet, ring-type ultrasonic autofocus.