Canon EOS REBEL T7i Instruction Manual page 413

F Remote Switch RS-60E3 (Sold Separately)
Remote Switch RS-60E3 comes with an approx. 60 cm/2.0 ft cord. When
connected to the camera's remote control terminal, it can be pressed
halfway and completely, just like the shutter button.
Using the Eyepiece Cover
When you take a picture without looking through the viewfinder, such as
when you use the self-timer, bulb exposure, or a remote switch, stray
light entering the viewfinder may cause the picture to look dark. To
prevent this, use the eyepiece cover (p.35) attached to the camera strap.
Note that attaching the eyepiece cover is not necessary in Live
View shooting or movie shooting.
Detach the eyecup.
1
Push the bottom of the eyecup to

detach it.
Attach the eyepiece cover.
2
Slide the eyepiece cover down into

the eyepiece groove to attach it.
After you finish shooting, detach the

eyepiece cover and attach the
eyecup by sliding it down into the
eyepiece groove.
Remote Control Shooting
413