Best 50mm lens for your camera: Pentax SMC DA 50mm f/1.8
Considerably more expensive than the other f/1.8 lenses in the group, the Pentax isn't especially strong on features.
There's no internal autofocus motor, the lens instead relying on a screw-drive from a motor in the camera body to actuate autofocus. There's also no focus distance scale, and a lens hood isn't supplied.
On the plus side, it's the most compact and lightest lens here and, despite weighing just 122g, build quality feels mostly very good.
That said, the mounting plate is plastic, rather than metal, but the lens feels robust overall.
As well as featuring multi-coated elements, the front element has a protection coating to repel dust and water. It's a shame that the mounting plate doesn't also have a rubber weather seal, as with both of the Nikon lenses in the group.
Handling is a bit of a mixed bag. The camera-driven autofocus is fast, but noisy compared with most other lenses on test.
The focus ring also rotates during autofocus and it's quite large, so you have to be careful not to foul its action with your fingers during handheld shooting.
A bonus is that the lens features Pentax's Quick-Shift focus system, which enables full-time manual override.
The Pentax has fairly minimal barrel distortion and does quite well at controlling colour fringing. Sharpness is good at f/1.8, impressive at medium apertures, and doesn't drop much at f/16. Overall image quality is pleasing, but the lens still seems overpriced.
Build quality: 3/5
Image quality: 4/5
Best 50mm lens for your camera: Sigma 50mm f/1.4 EX DG HSM
You can expect f/1.4 lenses to be bigger and heavier than their f/1.8 counterparts, but the Sigma really does go large in its design.
At 505g, it's about twice the weight of some f/1.4 lenses on test, and up to four times the weight of the f/1.8 lenses.
Meanwhile, its extra girth is reflected in its oversized 77mm filter thread, where most other 50mm f/1.4 lenses have a 58mm thread (55mm for the Sony).
Extra weight isn't necessarily bad news, however: the Sigma feels well balanced when shooting on big, full-frame cameras.
As with the Nikon lenses here, autofocus is courtesy of a fast and whisper-quiet ultrasonic ring-type system. It's accurate, and full-time manual override is silky smooth, with a well-positioned and high-precision focus ring.
Build quality feels tough and dependable, although there are no weather seals fitted to the lens. In common with only the Nikon 50mm f/1.4 lens group, the Sigma features nine diaphragm blades, where most others have only seven.
This helps to maintain a well-rounded aperture, from wide to medium settings. A petal-shaped lens hood and carrying pouch are supplied with the lens, both of which are of good quality.
A bonus of the Sigma's large front element is that vignetting is fairly minimal, even when shooting at f/1.4 on a full-frame body. Bokeh is smooth and pleasant, but the lens is a bit of an under-achiever when it comes to image sharpness at wide apertures.
Build quality: 4/5
Image quality: 4/5
PAGE 1 - Overview; Canon EF 50mm f/1.4 USM ; Canon EF 50mm f/1.8 II
PAGE 2 - Nikon AF-S 50mm f/1.4G; Nikon AF-S 50mm f/1.8G
PAGE 3 - Pentax SMC DA 50mm f/1.8; Sigma 50mm f/1.4 EX DG HSM
PAGE 4 - Sony 50mm f/1.4 A; Sony DT 50mm f/1.8 SAM
PAGE 5 - Image quality comparison & Verdict
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