Canon EOS 60D - Manual (Page 188)

188
Notes on Movie Shooting
Playback and TV connection
If the brightness changes during autoexposure movie shooting, that part
might look momentarily still when you playback the movie. In such cases,
shoot movies with manual exposure.
If you connect the camera to a TV set with an HDMI cable (p.209) and
shoot a movie in [1920x1080] or [1280x720], the movie being shot will
be displayed at a small size on the TV. However, the actual movie will be
properly recorded at the movie recording size that was set.
If you connect the camera to a TV set (p.209, 212) and shoot a movie,
the TV will not output any sound during the shooting. However, the
sound will be properly recorded.