In this blog, I will share with you my first impressions of the Sony 40mm f/2.5 prime lens. I’ve been using this lens for a few weeks, so this blog is an initial look and not a full review. The full review will come later after more extensive use in different conditions. For clarity, I purchased this lens with my own money, and I have no affiliations with Sony.

Purpose

This lens serves three key purposes. The first one is to provide a tiny, lightweight package for travel photographers or those wishing to have the camera on a neck or shoulder strap. Secondly, this lens can be a fantastic backup option if you’re travelling. Perhaps your main lens is a zoom, and should something happen to it, the 40mm f/2.5 can serve as a backup option without taking space in your bag. Lastly, this is a great street photography lens due to the focal length and compact size.

Focal Length

40mm is an incredibly versatile focal length and is best suited to travel, street photography, and even portraiture, although I haven’t used it for the latter personally. For street and travel photography, 40mm is ideal because it allows you to get everything in without having to be too close to the subjects. It’s also a focal length that closely resembles what your eyes see, so if you found a 35mm too wide, this could be a great alternative. Equally, if you love shooting at 50mm but want some extra breathing room, the 40mm can be great for that. Some of my favourite photos are somewhere between 35mm and 50mm.

Build Quality

The lens feels solid with a sturdy all-metal build. The focus dial is smooth and well damped. The aperture dial has solid, distinct clicks. Overall, the build quality seems great; however, this is something that will require time and heavy use to fully evaluate.

Size & Weight

Aside from the focal length, this would be the primary reason one would look at the 40mm. At 173 grams, it’s one of the lightest full-frame lenses out there, and you can really feel it when you have a camera around your neck. On a cross-body strap, you can barely notice the camera, even if fitted to the bigger A7R. If fitted to a smaller A7C, the total package is lighter and more compact than many APSC alternatives. As mentioned before, due to the size and weight, this is a lens I will bring with me on every single trip as a backup.

Features

Despite the size, the lens packs quote a few features. The primary one is environmental sealing, and while Sony never discloses how much it can withstand, I’ve never had any issues with any of their products in the rain. The second feature, which isn’t unique to this lens, but was a deciding factor in my purchase, is the custom button on the side. I program it to temporarily enable manual focus while being pressed. This allows me to press it with one finger, while using the other to adjust focus manually. As soon as I let go, the camera is back in AF. You get a click on/off switch which allows for a smooth aperture adjustment, and an AF/MF switch. The aperture ring is easy to use, and all the markings are clear to see. The lens comes with a lens hood, however I personally don’t use it.

Image Quality

All modern lenses have fantastic image quality, and I feel we’re at the point where any modern lens above £500 will produce good results. I can’t say anything specific about the 40mm f2.5. The image is tack sharp, the bokeh is nice, and the colours render as they should. No issues at all.

AF Performance

The AF is top-notch thanks to two linear motors. It’s silent, fast, and reliable. However, just like image quality, this is hardly a surprise. Nothing specific I can say about the AF, it works every single time exactly how you’d expect.

Summary

I don’t often do blanket recommendations for gear because what you shoot with is very specific to you and your style. However, I can make an exception for the 40mm f2.5. This is a must-have lens for all Sony shooters due to its size, weight, and performance. It makes for a good backup option or as your primary street photography tool. I only wish I got mine sooner.