After two weeks of lugging the Sigma 300-600mm F4 around for wildlife snaps at a refuge, the zoo, and my backyard, I walked away with some fantastic photos and a seriously sore shoulder. At 18.5 by 6.6 inches (HD) without the hood attached, and 8.8 pounds, the lens is a behemoth. That’s big even among its peers. The Sony FE 600mm F4 GM OSS is a little shorter (17.7 by 6.4 inches), but appreciably easier to handhold at 6.7 pounds.

(Credit: Jim Fisher)

However, the FE 600mm F4 doesn’t have a zoom option. With the Sigma 300-600mm F4, you get the narrow angle you’ll want for distant subjects like birds and the versatility to zoom in and out to get different angles when capturing field sports. Adding zoom while still maintaining the same F4 optics as the FE 600mm is no doubt a major factor, as the Sigma zoom uses a significant amount of glass in its 28-element/21-group optical formula.

Most other zoom lenses that reach the 600mm focal length don’t weigh as much, but they don’t gather as much light either. The Sigma 150-600mm F5-6.3 DG DN OS Sports, 60-600mm F4.5-6.3 DG DN OS Sports, and Sony FE 200-600mm F5.6-6.3 G OSS are pounds lighter and cost thousands less, but all capture less than half the light at the 600mm focal length versus the Sigma 300-600mm F4.

(Credit: Jim Fisher)

Still, at close to 9 pounds and 23 inches long with the hood attached, the 300-600mm stretched me to my physical limits for handheld photography. I paired it with a BlackRapid sling strap and wasn’t bothered by the weight hanging off my shoulder, but bringing the lens and camera up to eye level to hone in on a subject took some effort. Every day is an arm day with this lens.

You may prefer to pair the 300-600mm F4 with a monopod or tripod. I won’t fault you, and if I were using it for football or soccer instead of wildlife, I’d likely grab a monopod as a support. I like using the monopod with a big lens for sports because the action is typically at eye level, and I can more easily pivot the camera around to follow action without having to support its weight myself. But for birds and animals in the wild, I’m often pointing my camera up toward the sky or a branch, or down toward the water or ground, and find a monopod too restrictive.

(Credit: Jim Fisher)

It’s easy enough to attach a support. The lens includes a large tripod foot with forward and rear 1/4-inch-20 threads and a larger central 3/8-inch-16 post. The former is the size most quick-release plates use, while the latter is found on some heavy-duty tripods and straps. The foot also has dovetail cuts on its side, so it mounts directly into Arca-Swiss heads without the need for an additional quick-release plate.

The foot is permanently attached to a collar for 360-degree rotation and is switchable between continuous rotation and 90-degree detent clicks, with a thumbscrew to lock it in place. The collar also includes a pair of strap lugs, and the foot itself works as a carry point. There’s plenty of space between it and the lens barrel, so there’s no danger of scraping your knuckles, and the foot has a soft leatherette cover, so it provides a little bit of cushion for your fingers. The foot also has a Kensington lock slot, so you can lock it down for some extra peace of mind when covering events.

(Credit: Jim Fisher)

The lens may weigh close to 9 pounds, but it’s not due to dense materials. The lens houses its optics in a barrel made from light, tough magnesium alloy, and its hood is carbon fiber. Both the lens and hood are finished in white, which is a common choice for extra-big lenses. The color choice is practical—Sigma uses white thermal insulation paint so the lens reflects more sunlight than it absorbs, and doesn’t get as hot when used for prolonged periods on a sunny day. The downside is that the thermal paint shows scuffs readily; my review sample of the lens arrived with some noticeable black marks on the barrel and hood, and I’m pretty sure I added a few along the way.

(Credit: Jim Fisher)

The 300-600mm includes dust and splash protection, as well as oil- and moisture-repelling fluorine on its front element. The front glass is too large to support a filter, so the 300-600mm works with 40.5mm rear drop-in filters instead. It includes a clear glass filter, and it’s easy enough to swap it out for any other 40.5mm filter. The basic holder doesn’t support adjustable filters, however, so you’ll need to pick up the $193 Sigma CPL filter to set polarization or its $265 VND Filter if you want variable neutral density control.

In addition to the hood, the lens includes a slip-on lens cover to protect the glass during transport and storage, a shoulder strap, and a large soft case that doubles as a backpack.

(Credit: Jim Fisher)

Sigma makes two versions of the 300-600mm, one for L-Mount Alliance cameras and another in E-mount for Sony cameras. The two lenses are identical, but there are some functional differences between the camera systems. The L-mount version is compatible with rear 1.4x and 2.0x teleconverters, works with Sigma’s UD-11 USB configuration dock, and supports full-speed focus drive with any compatible camera. The E-mount version does not work with teleconverters and is limited to 15fps focus, restrictions that Sony puts on all third-party lenses, not just this one.