The Different Parts of the Camera

 Press this button to release the shutter. 

The shutter button press has two stages: 

Half-pressing the button activates the AF function,

 while pressing it down fully releases the shutter.

This is the section that connects the interchangeable lens to the camera body. To attach the lens, you line up the lens mount index  on the lens with the corresponding one on the lens mount and turn the lens clockwise until you hear a click.

Lens Mount Index

Align the mark on the lens with this mark when you are attaching or detaching a lens.

Red index: For EF lenses (Can be used on both Canon full-frame and APS-C DSLRs)
White index: For EF-S lenses (Can be used on Canon APS-C DSLRs)

Press this button when you want to detach the lens. The lens lock pin retracts when the button is pressed, enabling you to turn the lens freely. Before shooting, lock the lens into place by turning it until you hear a click.

The mirror is unique to DSLR cameras. It reflects light from the lens into the viewfinder, which lets the photographer see the shot through the viewfinder in real time. The mirror flips up immediately right before shutter release 

Viewfinder Display

Indicates the position of the focus during AF (autofocus) shooting. The selected AF point will be highlighted in red. You can choose to select an AF point automatically or manually.

Indicates the time interval during which the shutter is open. The shutter speed value is denoted in the "1/parameter" format. However, only the parameter value is shown in the viewfinder. Increasing the parameter value shortens the time interval the shutter remains open. Shutter speeds slower than 1/4 second are indicated as, for example, 0''3, 0''4, 0''5, 0''6, 0''8, 1'', or 1''3. In this case, 1"3 means 1.3 seconds.

Aperture Value

This value indicates the extent to which the aperture blades inside the lens are open. A smaller value means the aperture is more widely open, which allows more light to be captured. The selectable aperture value range varies according

 to the lens in use.

ISO Speed

The ISO speed setting varies constantly when the Auto setting is selected. A higher ISO speed makes it easier to capture shots of a dimly-lit scene.

ISO Speed Setting Button

Press this button to adjust the sensitivity of the camera toward light. ISO speed is an international standard that is determined based on the sensitivity of negative films.

Quick Control Button

Pressing this button displays the Quick Control screen (further explained in the section "Settings on the Quick Control Screen"), which allows you to confirm various camera settings at one glance and adjust them.