Conclusion

The Sigma 24mm F2 DG DN is a a super-sharp, very well built, fast wide-angle prime lens that is surprisingly affordable.

Its main selling points are undoubtedly its superlative build quality, vintage feel and perfect balance between size and speed.

Following in the footsteps of the other I-series lenses, the Sigma 24mm F2 DG DN is an incredibly well-built lens considering its mid-range price-tag,

From the weather-proof all-metal construction to the incredible attention to detail, such as the beautifully damped aperture and focus rings, ribbed lens hood, redesigned focus switch and the clever, and free, magnetic lens cap, it's clear that Sigma have lavished a huge amount of time and love on this lens.

A traditional aperture ring is a feature that we love on any lens, and Sigma's implementation of it on the 24mm F2 DG DN is nigh on perfect.

It has a lovely action, positive enough movements between the 1/3rd aperture stops, and a pronounced gap between f/22 and the Auto setting so that you can't inadvertently select it.

The only thing that we would have liked to see is a way of de-clicking it for video use, but then this is true of all the I-series lenses that Sigma have released so far.

The stepping motor auto-focus system is virtually silent, satisfyingly, quick, and almost 100% reliable.

This lens is a great performer optically, being pin-sharp throughout virtually all of the frame, even when shooting wide-open at f/2.

Vignetting is a little heavy wide-open, but chromatic aberrations and barrel distortion are well-controlled in the JPEG files (although Raw is another matter entirely) and the bokeh is appealing for such a wide-angle lens.

Compared to its main rivals, the Sigma 24mm F2 DG DN is really the midpoint between the super-fast but super-expensive Sony FE 24mm F1.4 GM and the smaller but crucially slower Sigma 24mm F3.5 DG DN.

There's also the Tamron 24mm F/2.8 Di III OSD M1:2 to consider, although that suffers from a sluggish autofocus system and high levels of distortion.

We didn't really think another we needed another 24mm prime lens for the Sony system - especially as Sigma already released the F3.5 version just last year - but it's difficult to ignore the Sigma 24mm F2 DG DN's great balance of optical excellence, features, speed and size.

Ratings (out of 5)
Design	4.5
Features	4.5
Ease-of-use	4.5
Image quality	4.5
Value for money	4.5