How to Attach or Remove a Lens from a Canon EOS 70D
With a dSLR (digital single lens reflex) camera, like the Canon EOS 70D, you can change lenses to suit different photographic needs, going from an extreme close-up lens to a super-long telephoto, for example. In addition, a dSLR lens has a focusing ring that gives you the option of focusing manually instead of relying on the camera's autofocus mechanism.
Whatever lens you choose, follow these steps to attach it to the camera body:
Turn the camera off and remove the cap that covers the lens mount on the front of the camera.
Remove the cap that covers the back of the lens.
Locate the proper lens mounting index on the camera body.
A mounting index is a mark that tells you where to align the lens with the camera body when connecting the two. Your camera has two of these marks, one red and one white, as shown in the following figure.
Which marker you use to align your lens depends on the lens type:
Canon EF-S lens: The white square is the mounting index.
Canon EF lens: The red dot is the mounting index.
With a non-Canon lens, check the lens manual for help with this step.Place the lens in the lens mount with the mounting indexes aligned.
Align the mounting index on the lens with the one on the camera.
The lens also has a mounting index. The above figure shows the one that appears on the 18–135mm EF-S kit lens.
Keeping the mounting indexes aligned, position the lens on the camera's lens mount.
Turn the lens clockwise until it clicks into place.
In other words, turn the lens toward the lens-release button, labeled in the figure above.
To remove a lens, turn the camera off, press the lens-release button, grip the rear collar of the lens, and turn the lens toward the shutter button side of the camera. When you feel the lens release from the mount, lift the lens off the camera. Place the rear protective cap onto the back of the lens, and if you aren't putting another lens on the camera, cover the lens mount with its protective cap, too.
Always switch lenses in a clean environment to reduce the risk of getting dust and dirt inside the camera or lens. For added safety, point the camera slightly down when performing this maneuver to help prevent flotsam in the air from being drawn into the camera by gravity.