Canon RF RF800/11 is STM Review

The Canon RF 800mm f/11 IS STM is a niche, lightweight super-telephoto lens. It offers incredible reach at a low price and weight, but the fixed f/11 aperture severely limits its use to bright, sunny conditions. It's a one-trick pony, but it does that trick for less than anything else.

If you're looking for a super-telephoto lens for Canon's RF mount, the Canon RF 800mm f/11 IS STM is a unique option. It's a lightweight, fixed-aperture lens designed for getting you incredibly close to distant subjects without breaking the bank or your back. It's a niche tool, best for specific types of photography like birding or plane spotting where you need a lot of reach and portability is key. The f/11 aperture means it needs a lot of light, so it's not a great all-around lens, but for its intended purpose, it's an interesting piece of gear.

Our data shows this lens lands in the middle of the pack for most performance metrics. Its autofocus speed and sharpness are about average for a lens in this category, sitting around the 44th to 46th percentile. That means it's not the fastest or the sharpest super-telephoto you can buy, but it gets the job done. In practice, you'll need good light and a steady hand (or a tripod) to get sharp shots, especially with that f/11 aperture. The image stabilization helps, but it's not a magic bullet for low-light situations.

The value proposition here is all about reach per dollar and pound. It's one of the cheapest ways to get 800mm on a Canon mirrorless camera. However, the price spread we see is wild, from a reasonable $847 to an absurd $216,363. Stick to reputable camera retailers for the sane price. For the cost, you're making big trade-offs, primarily with the slow aperture. If you need more light gathering ability, you'll have to look at much heavier and more expensive lenses like the RF 100-500mm or third-party options.

This lens doesn't really have direct competitors in the traditional sense, as its fixed f/11 design is unique. The closest comparisons are other budget super-telephotos. The older EF 800mm f/5.6L was a professional beast that cost five figures and weighed over 10 pounds. The Sigma 150-600mm Contemporary offers more flexibility with a zoom range and a faster variable aperture, though it's heavier and requires an adapter. For Canon shooters on a tight budget who must have 800mm, this is the only game in town. If you can live with less reach, the RF 100-400mm f/5.6-8 is a more versatile and sharper option for similar money.

Skip this lens if you shoot in anything less than ideal sunlight, need fast autofocus for moving subjects, or want a do-it-all lens. Landscape photographers will find the aperture too limiting for dynamic range. Portrait photographers have zero use for it. Sports photographers shooting indoor or evening events will find it useless. If you're a generalist, look at a standard telephoto zoom like the RF 70-200mm or the RF 100-400mm instead.

Should you buy the Canon RF 800mm f/11? Only if you have a very specific need. This is not a lens for general photography, portraits, or events. It's a specialized tool for wildlife enthusiasts, bird watchers, or sports photographers on a serious budget who shoot primarily in bright daylight. If your answer to 'do I absolutely need 800mm and can I only afford this one?' is yes, then it's your lens. For everyone else, a shorter, faster, and more versatile zoom lens will be a much better investment and get used far more often.