Of utmost importance is AF accuracy, and from that perspective, the Canon RF 100-400mm F5.6-8 IS USM Lens performance is excellent. Most modern lenses have correction profiles available (including in-camera), and distortion can easily be removed using these. Note that images from most cameras require some level of sharpening, but too-high sharpness settings are destructive to image details and hide the deficiencies of a lens. The minimum focus distance is 88cm (35") and the maximum magnification is 0.41x. If 100-400mm isn't enough for you, this lens is compatible with Canon's 1.4x and 2x teleconverters, with a commensurate further decrease in maximum aperture that may affect the camera's ability to autofocus. When used on a camera that utilizes a lens's entire image circle, peripheral shading can be expected at the widest aperture settings.

A relatively common lens aberration is axial (longitudinal, bokeh) CA, which causes non-coinciding focal planes of the various wavelengths of light.These are all shot hand-held as NORMAL (stairstep icon) JPGs; no tripods, FINE (quarter circle) JPGs or RAW CR3 files were used or needed.

Also better than a dedicated macro lens, this lens zooms, so you can change your framing without moving the camera. if you go out of your way to turn this OFF (or shoot raw and then use non-manufacturer software to process that data into images) then there are negligibly minor blue-green/orange-red fringes at 100mm, negligibly minor orange-red/blue-green fringes at 200mm and minor magenta/green fringes at 400mm.Canon's IS systems have long been very well behaved, meaning that the viewfinder image does not jump during IS activation, and I do not find myself fighting against IS while recomposing or recording video.

If this 1,200×900 pixel crop is about 6" (15cm) wide on your screen, the complete image would print at a huge 27½×41¼″ (70×105 cm) at this same high magnification. While filming video, you’ll notice how it takes several seconds for the system to operate at its best, so if possible wait a moment before you need to take a shot or start the action. Even once the stabilisation was fully deployed though, I found it hard to handhold video at 400mm without some kind of support. Your mileage will of course vary. Samples taken from the outer extreme of the image circle, full-frame corners, can be counted on to show a lens's weakest performance.

The handling of the Sigma 100-400mm f/5-6.3 DG OS HSM | C is excellent, as we said in our full review. The zoom and focus rings are smooth, and being able to twist the focus ring to override autofocus is a really useful feature for those times you need to be ultra-precise.

The RF 100-400 is Canon's first 100-400mm lens to ship without a tripod ring, and no tripod ring is optionally available.The softening effects of diffraction are typically strong by f/16, limiting the best possible optical performance. Above: As you know, the RF 100-400 has a variable aperture, starting at f5.6 at the short-end before dimming to f8 at the long-end, but one of the most revealing – and rarely discussed – specifications is exactly where in the range that aperture decreases. So I’ve measured it and made this lovely chart for you showing the aperture values for the old EF 100-400mm f4.5-5.6 at the top, the new RF 100-400 in the middle, and the RF 100-500 f4.5-7.1L at the bottom. So the new RF 100-400 starts at f5.6 and dims to f6.3 at 113mm, then to f7.1 at 156mm, then to its minimum f8 from 259mm to 400mm. So during this last section, it’s one stop slower than at 100-112mm. This makes the new RF zoom dimmer than the two L models, but it’s also considerably smaller, lighter and cheaper – in fact roughly one third the price of the EF 100-400 L and one quarter the price of the RF 100-500 L, so clearly it’s a completely different proposition. Smaller birds and animals, chipmunks for example, often need longer focal lengths to have a substantial size in the frame even at close distances. Mount an extension tube behind this lens to modestly decrease and increase those respective numbers. The wider focal lengths are especially ideal for portrait photography, including indoors, as long as adequate ambient light is available or flash is utilized.