First impressions shooting with the Sigma 18-35mm F1.8

By Richard Butler

This text was originally prepared as part of our preview content for the Sigma 18-35mm F1.8 DC HSM. We've kept it here to provide some additional perspective on what it's like to work with the lens.

Even as slightly jaded camera reviewers, we were pretty stunned when Sigma told us it was going to make an 18-35mm F1.8 zoom. The company has shown real ambition, particularly in recent years, to cement an increased reputation for itself - its 50mm F1.4, 85mm F1.4 and 35mm F1.4 lenses, for instance, have proved to be really impressive, with no need for caveats about them being from a third-party lens maker. But a constant F1.8 zoom? Was that even possible?

Well, having spent a little time shooting with a pre-production 18-35mm F1.8 DC HSM | Art (near enough to production to take publishable photos with, far enough away that we can't review it), it's clear that it is possible. So, what's it like? Sadly we weren't able to conduct a full test on the 18-35mm F1.8, but our experience is that its performance is pretty much in line with that of F2.8 zooms on full-frame.

And that's really the key to understanding the impression that I got: that it is what it isn't. And that it is what it is. Bear with me on this.

It is what it isn't.

Most people changing formats from APS-C to full-frame are likely to find themselves buying 24- or 28-70mm F2.8 zooms, as such a lens makes it easy to access the larger format's low-light and shallow depth-of-field capabilities. The key to understanding the Sigma 18-35mm F1.8 is to realize that it gives the same control over depth-of-field as a 28-50mm F2.8 would on a full-frame camera - it also allows you to shoot at wider apertures in any given situation, effectively cancelling out the greater low-light ability that a larger sensor would otherwise give. And, especially if you own a high-end APS-C camera, that can help to reduce some of the motivation for moving to full-frame.

The Sigma 18-35mm F1.8 DC HSM | Art gives the same control over depth of field that full-frame shooters are used to with constant F2.8 lenses. Photo by Barnaby Britton

The ability to shoot shallow depth-of-field images for the sample gallery on a sub-$1000 Canon Rebel, without having to resort to prime lenses was revelatory. The 18-35mm is a fairly heavy lens for such a small body (it'd be happier on a 60D, 7D, D7000 or D7100 with their more substantial grips), but concentrating on supporting the lens, rather than the body, meant it wasn't a problem, even with the Rebel's comparatively small grip. I was able to wander around pretty comfortably all afternoon with the Rebel dangling from one hand, having forgotten to put a camera strap onto it.

This shot, taken at ISO 1000 and F2 would have required a higher ISO with any other zoom lens. Photo by Richard Butler

It is what it is.

While the Sigma offers much of the capability of an F2.8 lens on a full-frame body, there's one respect in which it isn't quite a match for those zooms: reach. The 18-35mm F1.8 is equivalent to a 28-50mm zoom, and that simply can't compete with the flexibility of a 24-70mm full-frame lens which is usefully wider and longer than the Sigma. It means the Sigma can't quite offer the same 'on my camera most of the time' utility that a 24-70mm can bring. On the other hand, it still effectively replaces several fast primes - and good luck finding an 18mm F1.8 anywhere else.

Its more limited range means the Sigma doesn't reach into the traditional portrait territory in the way the full-frame zooms begin to. However, as someone who's never found portraiture that satisfying at the 75mm equivalent that a 50mm lens gives on APS-C, my preference would be to switch to a different, dedicated lens on either format. And, of course, there's no shortage of 50mm F1.8s to offer a cheap way of satisfying that ~70mm F2.8 equivalent need if you feel it. And such a lens is likely to be somewhat less intimidating to subjects than either the relatively large Sigma or a 'serious-looking' 24-70mm on a full-frame body.

The Sigma can focus down to around 12cm in front of the lens - making the 18-35mm a pretty flexible all-round lens. Photo by Barnaby Britton

While it lacks something in range, it is still pretty flexible - it has a minimum focusing distance of just 28cm (which means a working distance of 12cm in front on the lens) which, while not exactly putting it in Macro territory, means you'll rarely find yourself unable to focus because your subject is too close. Add to this the impressive-feeling build quality that Sigma has applied to its well-regarded 35mm, 50mm and 85mm F1.4s and the 18-35mm makes a good impression. Despite Sigma giving us a list of ways in which this sample's build may not match up to final production standards, it still feels very nicely put together, with both the focus and zoom rings giving a smooth, positive feel.

Overall the Sigma seems extremely promising and I've been pretty pleased with the results I and my colleagues achieved with it. Its range means it's unlikely to be the 'one lens to rule them all' for many people, but if I were an owner of an APS-C DSLR that I liked, this might help dispel the idea that APS-C is somehow just a stepping-stone to the quasi-mythically 'optimal' full-frame format (an idea Nikon and Canon have no incentive to challenge). The fact remains that APS-C is by far the most widely-used format in the DSLR era, and this lens should strengthen the cost/size/flexibility proposition that it offers.