Is this budget fast prime lens the perfect choice for Alpha 7 users? Andy Westlake finds out
Sony FE 50mm f/1.8 review: Image quality
The FE 50mm f/1.8’s focusing may be disappointing, but its optical quality is quite the opposite. Indeed, the images it creates are generally excellent given its price. Wide open, it combines impressive sharpness in the focal plane with attractive background blur. Stopped down to its optimum apertures it gives excellent levels of detail right across the frame. This behaviour is broadly typical of double Gauss 50mm f/1.8 lenses in general, but the aspherical element seems to be doing its job, and corner sharpness at large apertures is rather better than usual for designs that rely purely on conventional spherical lens surfaces.
One further point that’s easily overlooked is that lenses this good can also give sharper-than-usual shots when stopped down considerably, because while the softening effect of diffraction is impossible to avoid, there are few other aberrations to compound it.
Distortion is, to all intents and purposes, non-existent as is lateral chromatic aberration. Vignetting is quite visible at f/1.8, but it isn’t visually objectionable and adds character to selective focus shots that often helps to concentrate attention on the subject.
However, there is some longitudinal chromatic aberration, which manifests as coloured fringing around bright highlights when shooting at large apertures, particularly in out-of-focus areas of the frame. While this can sometimes be detrimental to your images and is difficult to remove in post-processing, you’ll struggle to find a better-corrected fast prime at this kind of price.
Out-of-focus backgrounds are usually rendered smoothly, although bright highlights tend to come out somewhat hard-edged, and become increasingly oval as you move off-centre.
Overall, the FE 50mm f/1.8 is capable of giving some very nice-looking images. More modern designs such as the Sony FE Planar T* 50mm f/1.4 ZA that we reviewed recently (AP 20 August) can certainly give even better results, but at a very much higher price.