Getting more reach in camera

Advantage of APS-C sensors and digital teleconverters

THE CROP factor of smaller APS-C sensors means that they provide more ‘reach’ than full-frame sensors, which can be a benefit when shooting with telephoto lenses. It is the same as attaching a 1.6x extender to the lens, but without the extra cost, loss of light and reduced image quality. Mount a 500mm lens on an EOS R10 (with an APS-C sensor) and you get the same view as an 800mm lens on a full-frame camera.

Full-frame EOS R cameras give you the option of choosing an APS-C size 1.6x crop rather than using the full area of the sensor – you’ll find this under ‘Cropping/aspect ratio’ in the red Shooting menu. You’ll lose some pixels though; when the 1.6x crop is enabled on the EOS RP for example, the resolution drops from 26MP to 10.1MP. Attach an RF-S or (via a mount adaptor) an EF-S lens to a full-frame EOS R body, and the camera will automatically switch to a 1.6x crop to match the smaller image projected by these APS-C lenses.

Canon also introduced a new ‘digital teleconverter’ function in the EOS R6 Mark II. This provides a 2x or 4x zoom effect. Rather than giving you a cropped image with a lower resolution, the camera digitally upsizes the image to give you a JPEG with the original recording resolution. If you shoot an L-quality JPEG (6000x4000) with a 300mm lens and select the 2x zoom, you’ll record an L-quality JPEG (6000x4000) but with a view equivalent to a 600mm lens. However, overall image quality will be lower, as the image is effectively enlarged. The digital teleconverter and 1.6x crop function can even be combined to give even more reach – of 3.2x or 6.4x!