Pushing the Limits

The Sigma 300-600mm F4 DG OS Sports lens is truly unique, filling a gap in the world of sports and wildlife photography. While there are comparable focal lengths on the market, no other manufacturer offers this combination of reach and speed in a single, purpose-built package. To put this lens through a trial run, I took it to Kelly Canyon in East Idaho to photograph the King of Kelly’s hill climb, one of the largest snowmobile races in the country, featuring over 1,300 racers tearing up the mountain at speeds of 40mph-50mph. For two days in the mountains, I paired the Sigma 300-600mm F4 with the Leica SL2-S to test its capabilities.

Singular Lens

No other lens currently on the market compares to the Sigma 300-600mm F4 DG OS Sports. Here’s how the competition stacks up:

Sony has a 200-600mm f/5.6-6.3, which provides more range but with a sacrifice in the loss of light.

Canon offers a 100-300mm f/2.8 L and a 200-400mm f/4L IS USM with a built-in 2X teleconverter, however, once the teleconverter is applied, there is a loss of light—unlike Sigma’s 300-600mm f/4 DG OS, which is consistent through each focal length.

Nikon has a Nikkor Z 180-600mm f/5.6-6.3 VR, but nothing that directly competes with the Sigma 300-600mm f/4 DG OS.

To put it into perspective, here’s the current breakdown of price for each of these lenses (new).

• Sony FE 200-600mm f/5.6-6.3 G OSS: $1,999
• Canon RF100-300mm F2.8L IS USM: $9,499
• Canon EF 200-400mm f/4L IS USM: $11,099
• Nikon Nikkor Z 180-600mm f/5.6-6.3 VR: $1,896
• Sigma 300-600mm f/4 DG OS Sports: $5,999

This lens has the potential to replace lenses on the market now in three prime focal lengths and apertures:

• Sony FE, Canon EF, Nikon F 300mm f/2.8
• Sony FE, Canon RF, Nikon Z 400mm f/2.8
• Sony FE, Canon RF, Nikon Z 600mm f/4

Sigma currently offers this lens in only L-Mount and Sony E-Mount, which narrows the audience but ensures that users of these systems have access to something unlike anything else on the market.

Performance

On both days of the race, temperatures hovered around zero degrees Fahrenheit, with harsh winds and unpredictable lighting. Despite these conditions, the Sigma 300-600mm f/4 DG OS performed flawlessly. I used a monopod and fast shutter speeds to counteract fatigue and ensure the stunning results I hoped for and got.

Sharpness at 600mm f/4: This was one of my primary concerns, but the level of detail, from the riders’ helmets to the snow kicking up behind them, was incredible.

Autofocus and Subject Tracking: Given the narrow depth of field at 600mm f/4, I was skeptical about how well it would handle fast-moving subjects. But after a few test shots, I was blown away. The autofocus locked onto subjects quickly, keeping them sharp even as they raced toward me.

Low Light Handling: As daylight faded, I pushed the lens to its limits. The optical stabilization allowed me to use lower shutter speeds while still maintaining sharpness within the image.

Results

One of the biggest takeaways from this experience was the reaction to the images. After sharing a few of the photographs with the owner of the Kelly Canyon Resort, his response was simple but powerful: “I’ve never seen anything like this.”

I have used telephoto lenses in the past, such as the Sony 200-600mm f/5.6-6.3 and Canon’s 200-400mm f/4 IS USM, but I’ve never seen a lens with such clarity, sharpness, and precision in a single package. I imagine Canon’s EF 200-400mm f/4 IS USM would perform just as well in these same conditions, however, when considering the price tags and the extra range, Sigma has the upper hand.

When paired with either a Sony or Leica body, the Sigma 300-600mm f/4 DG OS produces images that feel almost unreal. Capturing a snowmobile racer charging at 50 mph and nailing focus at 600mm f/4 is exhilarating.

Sigma has done something truly disruptive here. The fact that they have priced this lens at $6,000 is astonishing, considering what it delivers. If Canon and Nikon aren’t already scratching their heads, they will be soon.

I’ve said this before, and I’ll say it again: Sigma makes me believe in zooms again. It all started with their 28-45mm F1.8 DG DN Art lens, which convinced me to invest in a Leica because it was only available for L-Mount and E-Mount. I suspect we’ll see more photographers making similar moves, drawn by Sigma’s bold innovation.

Strengths and Weaknesses

To be fair, this was some of the harshest conditions any piece of gear could be tested in. Working on a mountainside in sub-zero temperatures with extremely low light at f/4 is not what most users will experience. On day one, I started at ISO 6400 and worked my way down to ISO 400. On day two, I started at ISO 6400 and ended at ISO 25,000.

While photographing at ISO 25,000 and wide open at f/4, the Leica struggled with tracking in near darkness, which I suspect many other camera bodies would do as well. So instead of forcing the autofocus system, both on the camera and the lens, I shifted my approach: I manually pre-focused on specific spots and waited for racers to enter the frame. When they did, I fired off five shots, knowing that one or two would be sharp—and they were.

This technique was crucial as I worked late into the night, and while 90% of users may never find themselves in this scenario, it’s good to understand the limitations and advantages of working with such a lens.

With a weight of 8.78 pounds, this is not a lens you’ll want to spend much time hand holding, but it does offer 5.5 stops of optical stabilization at 600mm. This was crucial, especially when tracking high-speed motion in extreme conditions.

Sweet Spots

I found specific focal lengths where the lens truly excelled in this racing situation:

300mm f/4: Incredibly sharp; fast autofocus and responsiveness.

400-500mm range: A sweet spot in terms of focus sharpness, accuracy, and responsiveness.

600mm f/4: Stunning detail and reach, though more demanding on technique (depending on the subject).

When photographing at 600mm wide open at f/4, the margin for error is razor-thin. The depth of field is incredibly shallow, meaning both the lens and camera must be perfectly dialed in to capture tack-sharp images of fast-moving subjects. Any hesitation in autofocus or miscalculation in tracking can result in missed shots. The lens can struggle when you’re tracking a subject coming toward you. It’s better to stay locked in at a focal length and be prepared for the subject to come into focus.

For some reason, between 350-400mm felt slightly less responsive than the other ranges, but that could be due to my position and the angle of incoming racers. In a wildlife setting where subjects aren’t racing toward the camera at 50 mph, I expect this range would perform differently. Like all lenses, there comes a certain distance between you and the subject when the lens will no longer focus. But when you find the sweet spot, that’s where the magic happens.

Final Thoughts

The Sigma 300-600mm F4 is a game-changer for sports and wildlife photographers. It delivers sharp, high-contrast images at every focal length, excels in challenging conditions, and provides a unique toolset. Autofocus performance is impressive, and sharpness at 600mm f/4 is spectacular.

For those looking for the ultimate long-range f/4 zoom, this lens is a statement piece—both in performance and presence. I can confidently say that after two days in the harshest conditions, this lens exceeded every expectation.  •

Tyler Rickenbach is a filmmaker and photographer based in Idaho.

This review will be published in the June, 2025, print edition of Professional Photographer magazine.