Sony FE 50mm F2.5 G Review

Announced at the same time as the Sony FE 40mm F2.5 G and Sony FE 24mm F 2.8 G, the Sony FE 50mm F2.5 G is a compact full-frame prime lens designed for use on Sony’s mirrorless cameras.

On a Sony A7-series camera the FE 50mm F 2.5 G is regarded as a standard prime lens, a go-to focal length for a wide range of photography including travel, street, documentary and environmental portraiture. However, on a APS-C format camera such as the Sony A6600, it has an effective focal length of 75mm, which makes it an attractive option for portraiture.

Like the FE 40mm F.25 G, the FE 50mm F2.5 G is constructed from 9 elements in 9 groups but it has one ED (extra-low dispersion) element and two aspherical elements instead of three aspherical elements.

The ED element is there to suppress chromatic aberration so that colour fringing is reduced while the aspherical elements correct for a variety of aberrations and deliver high resolution across the frame.

Sony’s engineers have given the FE 50mm F2.5 G two linear motors for speedy, accurate autofocusing (AF) and to ensure the lens can keep up with the camera’s subject tracking capability.  Naturally, it’s compatible with Sony’s Eye AF system.

In addition, the manual focusing mechanism has a linear response, which means that small movements of the focusing ring translate into subtle adjustments in the focus.

The focusing system works internally, which means that the lens doesn’t change length nor the front element rotate during focusing. As a result, the camera’s balance remains constant during focusing, which is important when shooting video with the camera mounted on a gimbal. A non-rotating front element is also good news when using graduated or polarising filters.

Speaking of filters, the FE 50mm F2.5 G, like it’s 24mm and 40mm stablemates, accepts 49mm filters. That small size helps keep down the size of the overall kit but also reduces the cost of accessories.

Also like the 24mm f/2.8 and 40mm f/2.5 lenses, the the FE 50mm F2.5 G has an aperture ring. This has markings from f/2.5 to f/22 in 1/3EV steps as well as an ‘A’ setting. When set to ‘A’ the lens allows the aperture to be controlled via a dial on the camera.

Although the aperture ring has click stops, it can be ‘de-clicked’ using a switch on the barrel.

There’s also a customisable Focus Hold button and a switch to set the lens to automatic or manual focusing.

At 48mm or 1.8-inches in length and 68mm or 2.75-inches in diameter, the FE 50mm F2.5 G is very compact and, as the image below shows, it can hide amongst the 24mm f/2.8 and 40mm f/2.5 very easily.

It also weighs just 174g or 6.2oz, which means you’ll hardly notice it in your bag, and when it’s mounted on the Sony A7 III, you’re carrying less than 830g in total. It also feels nicely balanced.

Despite its low weight, the FE 50mm F2.5 G has an aluminium exterior and it’s dust and weather resistant. It also comes supplied with a conical or reversed-type lens hood.

When the aperture ring is de-clicked, it rotates with a smooth, easy action. The knurled ring gives good purchase and although it feels more natural to adjust the aperture setting with your index finger and thumb, it can be done with just one finger if you want.

With the ring set to click, there’s clear feedback on any adjustment, you can tell easily how many 1/3EV steps you have adjusted without having to look at the value in the viewfinder or on the ring itself.

The focus ring also moves smoothly and has just the right level of resistance. It would be nice to see a distance scale to enable the focus to be preset without looking in the viewfinder, but Sony hasn’t provided one.

Above the AF/MF switch the lens barrel, the FE 50mm f/2.5 G has a customisable button. Sony cameras enable one of a huge range of options to the assigned to this button and its worth spending time thinking about what you photograph most often and the features you need to access frequently.  I find it handy to use it to access the Eye AF subject options, but if you shoot street photography rather than people and dogs, you may prefer to use it do something else.

I tested the Sony FE 50mm f/2.5 G on the 61Mp Sony A7R IV and it proved to be a good match for such a high resolution camera. There’s excellent sharpness across the frame, even when the lens is wide open, but the corners are sharpest when the aperture is closed down to at least f/4.

I’d happily use any of the FE 50mm f/2.5 G’s aperture settings but if you look carefully you’ll see slight softening as a result of diffraction when images are captured at f/16 and f/22.

There’s subtle vignetting visible at the widest aperture settings when the in-camera or post-capture profiles aren’t applied, but again, closing to f/4 (or using the profiles) addresses it.

Distortion isn’t an issue with the FE 50mm F2.5 G. If you photograph a subject with lots of straight lines and then turn the correction profiles on and off during raw file processing, you may see a slight change the lines which indicates there is in fact some barrel distortion but it’s not noticeable in images.

The bokeh, a term referring to the quality of out of focus areas, generally looks nice and smooth in images captured with the Sony FE 50mm F2.5 G. Central small highlights are also round, but they become cat’s eye or lemon-shaped towards the edges of the frame. I also noticed some chromatic aberration around the edges of some bokeh balls, but it’s not especially problematic.

If you remove the supplied lens hood and angle the front element of the lens so that sunlight skips across it, but can force some flare to be visible, but with the lens hood in place, there’s no need to worry.

When mounted on the Sony A7R IV, the FE 50mm F/2.5 G focuses very quickly and silently. Other than to test the manual focusing, I had to need to use manual focusing as the camera and lens always delivered a perfectly sharp result when the autofocus system was in action. However, there are times when it’s useful to focus manually and it could be used to get the 4cm closer focusing.

There is a little focus breathing, but I only noticed it when making significant adjustments to the focus distance, it’s not an issue with minor changes.

I was only able to find a few limited examples of chromatic aberration, it’s clear the lens keeps it under good control.

Follow the link to browse and download full-resolution images from the Sony A7R IV with the Sony FE 50mm f/2.5 G mounted.

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Sony has introduces an enticing trio of prime lenses in the Sony FE 40mm F2.5 G, Sony FE 24mm F 2.8 G and the FE 50mm F2.5 G and the 50mm lens delivers some of the best results from the set. While f/2.5 seems a little slow for a 50mm lens, the smaller aperture enables the lens to be so small. The FE 50mm F2.5 G is also very nicely built, offering an aperture ring and customisable button on its weather-proof barrel.