Verdict

The Sigma 300-600mm f4 is a remarkable lens in terms of flexibility, price and performance. It starts by giving you a 600mm f4 at roughly half the price of those from Sony, Canon and Nikon, already making it tremendous value. 

It then gives you the chance to zoom out to 300mm, giving you greater flexibility than a traditional prime, and best of all, in my tests the optical quality was superb, delivering crisp details throughout the range and across the frame wide-open at f4.

The build quality and feature-set are also excellent, including a tripod collar that can be clicked or declicked and an Arca dovetail carved into the foot, neither of which you’ll find from the big names.

So what’s not to like? Well most obviously it’s a heavy lens, roughly 4kg alone, or around 5 when fitted with the hood and mounted on a body. That’s around 1kg heavier than the most recent 600mm f4 lenses from the big names, although it should be noted some earlier models were heavier, and of course with the Sigma you’re getting a zoom that could replace multiple primes.

Secondly, it’s not parfocal, which means the focus needs to be adjusted as you zoom. This can be an issue if you’re shooting a subject that’s approaching quickly while adjusting the zoom to reframe. In those situations you may lose focus temporarily. So it’s best to treat the Sigma zoom as a series of primes and set your focal length before each burst.

Third are the restrictions Sony enforces on third party lenses, namely a top burst speed of 15fps when using continuous autofocus and incompatibility with their teleconverters. Of course this only affects the e-mount version when mounted on a Sony body, and I personally feel the range is sufficient without TCs on a modern high-res camera. But the 15fps limit is harder to swallow for action shooters, especially if they have a Sony body that offers 30 to 120fps with their own lenses.

L-mount owners, or those adapting the e-mount version to other systems needn’t worry though, with the lens supporting faster bursts, and in the case of L-mount, working with Sigma’s own teleconverters. Indeed for L-mount owners, it’s becomes by far the best high-end super-telephoto lens to date – to be fair the only one – but for e-mount there are alternatives to consider. 

For example, for much the same money as the Sigma zoom you could get Sony’s 300mm f2.8 and enjoy not just its brighter aperture and lighter weight, but support for both the fastest bursts and Sony’s TCs. Fit a 1.4x TC and you could have a 420mm f4 prime, matching the Sigma aperture, but at 600mm with a 2x TC you’d be working at f5.6. You’d still have the fast bursts, but with optics one stop slower, no chance to fine-tune the focal length, and of course the delay when fitting the TC. But then if you’re hiking with the lens to reach a distant subject, it’ll be a lot easier weight-wise.

Ultimately you need to ask yourself if you’d exploit the flexibility of a zoom, and whether you need f4 at 600mm, and equally if f4 is sufficient at 300. Then you have to factor in if you need a parfocal zoom and in particular if the restrictions on Sony bodies are deal-breakers or not.

But regardless Sigma has really shaken-up the super-telephoto end of the market by delivering not just a uniquely flexible high-end lens, but one that substantially undercuts traditional big primes while still boasting excellent performance. It’s their most professional lens to date and one that will open-up the joy of bright long primes to a broader audience.

Check prices on the Sigma 300-600mm f4 DG OS at B&H, Adorama, WEX UK or Calumet.de. Buy used gear from MPB. Sell your used gear to MPB. Alternatively get yourself a copy of my In Camera book, an official Cameralabs T-shirt or mug, or treat me to a coffee! Thanks!