Canon EF 50mm f/1.8 STM £105/$125

A major upgrade over Canon’s previous ‘nifty fifty’

Certainly no heavyweight, Canon’s latest 50mm f/1.8 is only 30g heavier, 1mm wider and 16mm longer than the 40mm pancake lens on test. That’s pretty impressive, considering its longer focal length and faster f/1.8 aperture rating. The filter attachment thread is even smaller, at 49mm, but this time the front element is quite deeply recessed, making the ES-68 lens hood a genuinely ‘optional’ accessory.

Design similarities between this lens and the 40mm pancake include a gear type STM autofocus system, with the same strengths and weaknesses. Again, the inner barrel of the 50mm lens extends at shorter focus distances but doesn’t rotate. The non-rotation is helpful when using circular polarizing or ND grad filters, although that’s unlikely in portraiture.

As well as its more advanced autofocus system, other upgrades over the previous EF 50mm f/1.8 lenses include a metal rather than plastic mounting plate, and seven diaphragm blades rather than five, which give a more well-rounded aperture. This is particularly useful for avoiding the obvious pentagonal shapes of defocused bright objects when stopping down a little, which plagued images taken with the earlier 50mm lenses.

Performance

Naturally, the aperture of this f/1.8 lens doesn’t go quite as wide as in Canon’s 50mm f/1.4 optic but, when using both lenses at f/1.8, this less-expensive model delivers greater sharpness from the centre of the frame to the corners. Performance in terms of colour fringing is about equal, and there’s marginally less barrel distortion. Overall, the new 50mm f/1.8 STM is a steal at the price.