Canon RF 800mm F/11 IS STM

This Canon prime serves photographers who photograph distant subjects. It pairs a fixed 800mm focal length with the RF mount and full-frame coverage. That makes it a natural fit for wildlife, birds and outdoor sport. Aircraft, surfers and the moon are equally at home here. Canon introduced the lens in 2020, and it remains in production.

The trade-off to weigh is light gathering. The fixed F/11 aperture needs bright conditions or a raised ISO. That limit never changes during a shoot, so plan around it. Overcast skies and deep shade will stretch the ISO further.

It weighs 2 lb 12.4 oz (1260 g), measures 13.85 in (351.8 mm) long and has a barrel 4 in (101.6 mm) wide.

That weight keeps the lens practical to carry through a day in the field. The front accepts screw-in filters, and a filter must match the 95mm thread of the lens.

At 800mm, distant subjects become large in the frame. A bird across a marsh, a surfer offshore or a plane overhead fills the picture without cropping. The fixed focal length means you frame by choosing your position in advance. You cannot zoom out to take in a wider scene.

The aperture is fixed at F/11, with no adjustable iris. You cannot open up in shade or stop down for more depth of field. Work in good light, raise the ISO, or accept slower shutter speeds. Morning and evening light may fall short for fast action.

Depth of field still looks shallow at this focal length. A distant background falls well out of focus, which helps a subject stand apart from busy surroundings. A small focusing error can shift the sharp zone off the subject.

Closest focus sits at 19.7 ft (600 cm), so the lens is not built for tight indoor spaces. Maximum magnification is 0.14x, which renders larger nearby subjects at good size. This lens scores 50 out of 100 in our optics assessment.

Image stabilisation is built in. At 800mm, small camera movements show strongly in the frame, and the stabiliser helps hold the shot steady. Without it, only fast shutter speeds would keep handheld frames sharp at this focal length. It steadies the camera only, so a moving subject still needs a fast enough shutter.

There is no weather sealing. In dust or drizzle, keep the lens protected and clean it afterwards. The glass also lacks a fluorine coating, so water and oil on the front element take more deliberate wiping.

The feature set is short. Our features score is 41 out of 100.

The optical path uses 11 elements in 8 groups, with the totals listed in the specification table. Two of those elements are designed to help reduce chromatic aberration. That is the colour fringing that can appear at high-contrast edges, such as a bright bird against dark water. Our construction score is 15 out of 100.