Best 50mm lens for your camera: Sony 50mm f/1.4 A
The Sony 50mm f/1.4’s design follows the opposite path to the competing Sigma lens. Downsizing seems to be key, with a size and weight that’s much more in keeping with f/1.8 lenses. It also has a relatively small filter thread of 55mm.
Surprisingly, the lens itself is even smaller than Sony’s 50mm f/1.8 lens, despite the fact that the f/1.4 is compatible with full-frame bodies, whereas the f/1.8 is designed exclusively for cameras with APS-C format sensors.
Sony has managed to squeeze in a focus distance scale, but the focus ring seems almost like an afterthought.
It’s small and placed at the forward end of the lens barrel, and has no knurling to assist a secure hold. That’s not an altogether bad thing, however, as the focus ring rotates during autofocus.
Contributing to the fairly lightweight build of 220g is the absence of a built-in autofocus motor. Instead, autofocus needs to be driven from an in-camera motor via a screw-drive.
As with the similar arrangement in the Pentax 50mm lens, autofocus is fairly fast, but the Sony is a little quieter.
The minimum focus distance of 45cm, maximum magnification factor of 1.5x, and the provision of a seven-blade diaphragm are all par for the course.
There’s a noticeable darkening of image corners when using the lens at wide apertures on a full-frame body like the A99, but it’s not too bad on APS-C format cameras. Sharpness and distortion levels are average for this class of lens, but colour fringing is relatively poor.
Build quality: 3/5
Image quality: 3/5
Best 50mm lens for your camera: Sony DT 50mm f/1.8 SAM
Compared with the Sony 50mm f/1.4, which is the second most expensive in the group, this f/1.8 lens costs little more than a third of the price.
It’s designed exclusively for cameras that feature APS-C format image sensors, so can only be used in crop mode on full-frame bodies like the Sony A99.
It’s quite small and lightweight, but feels a bit plasticky and, like the Canon and Pentax f/1.8 lenses, has a plastic rather than metal mounting plate.
Unlike the Sony f/1.4 lens, the focus distance scale is printed on the focus ring (which rotates during autofocus), instead of being positioned beneath a viewing window.
But at least it does have a focus distance scale, which is absent on the Canon and Pentax f/1.8 lenses.
Another difference between the Sony lenses is that this one’s an SAM lens, with a built-in Smooth Autofocus Motor.
It’s a fairly basic electric motor and, on our A77 body, offered neither an increase in autofocus speed nor reduction in noise, compared with the f/1.4.
Whereas all other lenses in the group have a minimum focus distance of 45cm, this one focuses down to 34cm. As a result, the maximum magnification factor is slightly larger, at 0.2x rather than the more typical 0.15x.
Sharpness is marginally higher than in Sony’s more expensive f/1.4 lens, and colour fringing is better controlled. Vignetting on APS-C bodies is worse than with other lenses on test, which is no real surprise when all the others are full-frame compatible.
Build quality: 3/5
Image quality: 3/5
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
Getting Sharp Images: every photo technique you need to know starting out
Best camera focus techniques: 10 surefire ways to get sharp photos
Manual focus: what you need to know to get sharp images
Focus modes: how, when and why you need to change your AF settings