The Sony 50mm F1.4 is a pretty well-made lens, which feels reassuringly 'dense' and certainly as solidly built as any other lens in its class. The mount is metal, and the barrel constructed of high-quality plastics with a totally smooth rubber focus ring, and a large smooth rubber grip surrounding much of the barrel to aid mounting/dismounting the lens. The front element is recessed from the filter thread by about 6mm, which should offer some protection against stray light, and the entire optical assembly moves backwards and forwards as a unit by about 8mm for focusing.
Compared to Minolta 50mm F1.4 ('RS' version)
Here's the Sony 50mm F1.4 alongside its immediate predecessor, the Minolta 50mm F1.4 RS (which we have used in our reviews of Konica Minolta and Sony APS-C DSLRs since the original Maxxum/Dynax 7D). As you can see there's little aside from Sony's Alpha-brand restyling to distinguish them, the two lenses are identical not just in size but also in weight (to the gram) and even share the same hood design. However the Sony does add three extra contacts to the lens mount which are used to communicate focus distance information to the camera body (mainly useful to refine the metering when using direct flash). The coatings are also visibly different - the Sony imparts a greenish tinge to reflections, the Minolta magenta - presumably to minimize image-degrading reflection of light from the sensor to the lens and back. But while those Sony grips certainly score points for minimalist style, it's very much at the expense of in-the-field practicality.
We'll see what measurable optical differences there are (if any) between these lenses later in the review.
On the camera
The 50mm F1.4 is about average in size for its class, making it a distinctly compact lens especially in comparison to Sigma's monster 50mm F1.4 EX DG HSM. It balances well on all Sony (or Konica Minolta) DSLRs from the full-frame Alpha 900 to the relatively compact Alpha 350, with the focus ring falling readily to hand when required.
The 50mm F1.4 relies on the body’s built-in AF motor for focusing, which makes it slightly noisy in use (although this is entirely dependent upon the camera body), and certainly more obtrusive than the HSM-equipped Sigma 50mm F1.4 EX DG. Autofocus was fast and decisive on all of the bodies we used for testing (although as always, it must also be noted that focus speed and accuracy is dependent upon a number of variables, including the camera body used, subject contrast, and light levels).
Unfortunately our test sample consistently back-focused, setting the plane of sharpest focus slightly behind the desired point (for example when shooting a portrait and focusing on the eyes, the subject's ears would instead be sharp). This was clearly a lens issue, as the behavior was consistent across all camera bodies used (Alpha 350, Alpha 700, Alpha 900), and all of these were fully capable of focusing the Minolta 50mm F1.4 correctly. Accuracy did not improve with refocusing a second time after initial focus confirmation.
On the Alpha 900, setting an AF Micro Adjustment of -7 allowed the camera to achieve correct focus, and this setting was used for the sample shots at the end of the review. This was an acceptable workaround for our purposes, but of course didn't help on older bodies. If we'd bought a lens with this problem for our own personal use we'd probably consider such behavior unacceptable, and either exchange it for new copy, or return it to Sony for calibration. (Note that front/back-focus issues can be experienced by users of most if not all manufacturers' systems, and are specific to individual lens samples rather than models.)
Lens body elements
Reported aperture vs focal length
This lens allows an aperture range from F1.4 to F22 to be selected.