Canon EOS Rebel T5i 18-55mm IS STM Lens Kit Instruction Manual - Page 40

Attaching and Detaching a Lens About Zooming Detaching the Lens To zoom, turn the zoom ring on the lens with your fingers. If you want to zoom, do it before focusing. Turning the zoom ring after achieving focus may throw off the focus. While pressing the lens release button, turn the lens as shown by the arrows. Turn the lens until it stops, then detach it. Attach the rear lens cap to the detached lens. Do not look at the sun directly through any lens. Doing so may cause loss of vision. When attaching or detaching a lens, set the camera's power switch to . If the front part (focusing ring) of the lens rotates during autofocusing, do not touch the rotating part. If you purchased a lens kit with the EF-S18-55mm f/3.5-5.6 IS STM or EF-S18-135mm f/3.5-5.6 IS STM lens, see "Handling Precautions" on page 346. Image Conversion Factor Since the image sensor size is smaller than the 35mm film format, it will look like the lens focal length is increased by approx. 1.6x. 40 Image sensor size (Approx.) (22.3 x 14.9 mm / 0.88 x 0.59 in.) 35mm image size (36 x 24 mm / 1.42 x 0.94 in.)