Intro

The Sigma 10-18mm f2.8 DC DN is an ultra wide zoom designed for APSC mirrorless cameras. Announced in October 2023 at a price of around $599 or pounds, it’s available in Fujifilm X, Sony E and Leica L mounts, and while designed for APSC sensors, it’ll also work on full-frame Sony and Leica L-mount bodies in a cropped mode, albeit at a reduced resolution for photos.

There’s plenty of wide zooms for the X and E mounts, but arguably the closest rival for the new Sigma is Tamron’s 11-20mm f2.8, launched about six months earlier, and also available in Fujifilm and Sony mounts for around $700-800 or pounds. So already the Sigma is a little more affordable. For my video review below, I tested a pre-production Sigma 10-18 on my Sony A6400, but if you’d prefer to read the written highlights, keep scrolling!

The 1.5x field reduction of most APSC sensors means the coverage is equivalent to 15-27mm in full-frame terms, delivering a classic ultra-wide to standard wide range. Meanwhile the bright f2.8 aperture allows you to keep sensitivities low and achieve mild background blur if you can get close to your subject.

The 10-18 is a member of Sigma’s more affordable Contemporary series, measures 72x64mm and weighs 255g. This makes it roughly the same diameter as Tamron’s 11-20 2.8, but 22mm shorter and around two thirds the weight. The Tamron isn’t exactly large or heavy, but the Sigma is noticeably more compact.

The design and controls are very simple with just two rings and no switches. Closest to the lens mount is a smooth and free-spinning manual focusing ring, although with the ridges flush to the barrel on either side, I didn’t find it the most comfortable in use.

Towards the end of the barrel is the zoom ring, with the lens physically shortest when set to the 18mm focal length. As you adjust the zoom wider to the 10mm focal length, the whole end of the barrel extends by about a centimeter. It’s a smooth mechanism with quite a short throw which also doesn’t rotate the 67mm filter thread.

Sigma supplies a petal lens hood that pushes onto the end of the barrel. It stays in place securely without the usual bayonet twist and lock, but I’m not sure it’s that much of a time-saver.

In terms of dust and moisture, there’s a rubber grommet at the mount-end, but I believe that’s where the sealing ends, so be warned under wet conditions.

To measure the image quality at a typical landscape distance, I photographed Brighton Pier with the Sigma 10-18mm, starting at 10mm for an ultra-wide 15mm equivalent field of view, and with the aperture wide-open.

Again I used my Sony A6400 for the tests in this review, with Distortion Compensation set to Auto, as this is how the lens is designed to be used, and as always I’ve angled the view so that details run into the corners.

Taking a closer look at the middle with the aperture wide-open at f2.8, the Sigma lens is looking pretty good, although if you can close it a stop or two, you’ll gain a little extra crispness.

Return to f2.8 before heading out into the corners and you’ll see the details becoming softer in the extremes, but not too bad unless you’re really pixel-peeping. 

As you close the aperture, the details become better defined, and for the best performance across the frame, I’d try to use around f5.6 to f8.

Next for the lens mid-way through its focal range at 14mm, again wide-open at f2.8. Taking a closer look in the centre of the frame tells the same story as at 10mm: there’s plenty of detail but you can enjoy a slight boost in crispness if you can close the aperture a stop or two.

Now let’s open the aperture again to f2.8 before moving into the corners, where you’ll again see softness in the extremes. As before, this improves as you close the aperture, and again by f8 it’s looking pretty good from corner to corner.

And finally for my distant quality test, the lens set to its longest focal length of 18mm and again with the aperture wide-open at f2.8. Taking a closer look in the middle shows the lens performing well out of the gate with crisp details and little benefit to closing it down.

With the aperture opened to f2.8 again and heading into the corners, there’s some softening, but less than before and only in the very extremes. Close the aperture even just one stop to f4 and the corners at 18mm become much improved, although again at f5.6-f8 they can become even crisper.

Moving onto people, ultra-wide zooms may not be your first choice for portraits, but can be useful for environmental compositions where you see more of the surroundings, or of course group shots, especially when you can’t step back too far.

They’re also ideal for vlogging or presenting pieces to camera at close range, especially if you can keep your face towards the middle of the frame to minimise distortion.

This can work particularly well for product presentation style videos, with the close focusing distance allowing you to fill the frame with many subjects even with the lens fully zoomed-out to 10mm.

Sadly like the Tamron 11-20, the Sigma 10-18 doesn’t have optical stabilisation, so for handheld filming you’ll be relying on IBIS or digital compensation built-into your camera, or of course using something like a gimbal. 

My Sony 6400 has no built-in stabilisation, nor support for post compensation in Catalyst, so this is an unstabilised clip you’re watching. Sorry for the wobbles.

And finally to see the potential for bokeh blobs, I photographed this ornament with the lens zoomed to 18mm and positioned close to the minimum focusing distance of 19cm. I’ll go through the aperture range starting at f2.8.

Note if you set the lens to 10mm, you can focus as close as 11.6cm – these respective distances and the resulting reproduction is roughly similar to the Tamron. I have some examples at the closest distances on my sample images page.