Sony FE 40mm f/2.5 G Review

The Sony 40mm f/2.5 G is the lens you buy when you're tired of lugging heavy gear around. It's tiny, light, and built like a tank, but that f/2.5 aperture means you're giving up some light and background blur for the privilege. If you want a premium, compact prime for everyday shooting, this is it. Just know you're paying a Sony G-series premium for what is essentially a very nice, slightly slow lens.

The optical performance is solidly above average, landing in the 65th percentile, which is impressive for such a small package. The three aspherical elements keep things sharp. But the autofocus is just average, sitting in the 47th percentile. It's fine for street and casual portraits, but don't expect blazing speed for fast-moving subjects. The lack of stabilization hurts a bit in low light, but that's the trade-off for the tiny size.

It's hard to call this a good value. You're paying Sony G-series prices for a lens with an f/2.5 aperture. You're buying the exceptional build quality and tiny form factor, not groundbreaking optical performance. If those two things are your top priorities, it's worth it. If not, your money goes further elsewhere.

Look at the Viltrox 35mm f/1.7. It's cheaper, faster, and has solid AF. You give up the Sony's flawless build and compact size, but you gain over a stop of light. The Meike 55mm f/1.8 is another alternative – faster, with better bokeh, and still relatively compact. The Sony wins on pure portability and finish, but both competitors offer more performance per dollar, especially in low light.

This is a niche lens. Buy it if you're a Sony shooter who values a super small, high-quality everyday prime above all else, and you're okay with the f/2.5 speed limit. For everyone else, especially if you shoot in lower light or want more dramatic portraits, a faster third-party lens like the Viltrox 35mm f/1.7 is a smarter buy that gives you more for your money.