Canon EOS Rebel SL3 DSLR Camera with 18-55mm Lens (Black) - Manual (Page 192)

192
Menu Function Settings
Setting items for Live View shooting are shown on the [
z
] and [ 5 ] tabs in
Live View shooting.
z Still img aspect ratio N
You can change the image’s aspect ratio. [3:2] is set by default. The
area surrounding the Live View image is masked in black when the
following aspect ratios are set: [4:3] [16:9] [1:1] .
JPEG images will be saved with the set aspect ratio. RAW images will
always be saved with the [3:2] aspect ratio. The selected aspect ratio
information is added to the RAW image file. When you process the
RAW image with Digital Photo Professional (EOS software), this allows
you to generate an image with the same aspect ratio that was set for
shooting. In the case of the [4:3] , [16:9] , and [1:1] aspect ratios, the
lines to indicate the aspect ratio will appear during image playback, but
they are not actually drawn on the image.