If you’re considering the Canon RF 100-400mm lens, let me tell you—it’s worth the buy. I purchased it, and after nearly a year of use, I’m thrilled with its performance. While it’s not perfect, the lens is impressively good, especially for what it offers. It’s compact, lightweight, and costs less than $1,000 CAD. For a 400mm lens at that price point? That’s a steal.

In this review, I’ll share my hands-on experience with this lens, covering both the pros and the cons. I’ve put it through its paces shooting everything from skiing and landscapes in Iceland to wildlife photography featuring grizzly bears and chipmunks. So, let’s dive in.

The Downsides: Where the Canon RF 100-400mm Falls Short

1. It’s Not the Fastest Lens

The f/5.6-8 aperture means this isn’t the ideal lens for low-light situations. If you’re a professional wildlife or sports photographer shooting at dusk or in dim conditions, you might find the aperture limiting. However, for most casual photographers or those shooting in decent light, it’s not a deal-breaker. With today’s noise reduction tools in programs like Lightroom, you can easily bump up the ISO and clean things up in post-production.

2. Not Razor-Sharp for Landscapes at Full Zoom

While the lens does an admirable job with most subjects, I found it slightly lacking when zoomed in for landscape photography. When isolating distant mountain peaks at 400mm, the images aren’t as sharp as I’d hoped. It’s not enough to ruin a shot, but it’s noticeable—especially if you plan to print large-scale images. Below are two examples from Iceland: one at 16mm and one at 400mm. The latter isn’t perfect, but it’s still pretty good.

The Positives: Why This Lens Stands Out

1. Incredible Value for Money

For under $1,000 CAD (around $650 USD), you’re getting a versatile, high-quality lens. That kind of affordability is rare, especially for a 400mm telephoto lens. And the best part? It’s lightweight and easy to carry. At less than a kilogram, it weighs less than a can of beer—so it’s perfect for long hikes or multi-day trips.

2. Excellent Performance with Wildlife

One of my favorite shots with this lens was a close-up portrait of a young grizzly bear. This lens nailed the focus on the bear’s face, with just enough depth of field to blur out the background, creating a beautiful subject isolation. It brought back memories of a gorilla portrait I once missed because of poor lens quality. Thankfully, this grizzly shot turned out perfectly—and it’s one of my favorites to date.

3. Superb Close-Focus Capabilities

Beyond bears, I spent hours photographing chipmunks and ground squirrels with this lens. It performs exceptionally well at close distances, locking focus right on the animal’s eyes. Even at f/8, the images are crisp, clean, and full of detail. I could spend all day photographing small critters with this lens—and honestly, I have!

4. Reliable Autofocus and Stabilization for Action Shots

I’ve also used this lens extensively for video, including fast-action skiing scenes. During one shoot, I tracked a skier bombing down a hill directly toward me. The autofocus held perfectly, even at top speed. That performance is a testament to the combination of the RF 100-400mm and the Canon R6 Mark II.

The in-body image stabilization (IBIS) paired with the lens’s built-in stabilization ensures smooth footage, even when hand-held. In one instance, I set the camera on my backpack, and the results looked as steady as a tripod shot. That level of stability makes it an excellent choice for run-and-gun video work.

Final Thoughts: Should You Buy the Canon RF 100-400mm?

In short—yes. If you’re on the fence, I’d say go for it. This lens offers fantastic value for its price and is a joy to shoot with. While it’s not as sharp as high-end lenses like a 70-200mm f/2.8, it’s far lighter and much easier to carry. That makes it ideal for adventures where every gram counts, like the 80km hike I did recently. On that trek, I left all my heavy glass behind and carried only lightweight lenses, including this one—and it was totally worth it.

The RF 100-400mm now lives in my camera bag permanently. Whether I’m climbing mountains or photographing wildlife, it’s always with me. For the price, portability, and performance, I’d buy it again in a heartbeat.

If you're looking for a versatile telephoto lens without breaking the bank, this is the one. Happy shooting, and stay tuned for more gear reviews soon!

Canon RF 100-400mm Lens Review: A Practical Photographer’s Perspective