The Manfrotto SYMPLA Deluxe Remote Control for Canon DSLRs wires
by USB cable right into the firmware of a Canon DSLR and allows over a
dozen camera controls including control of aperture, ISO, shutter speed,
and focus direction. It also features an LCD screen that indicates
information such as aperture and color temperature. (Please click on
"Specifications" tab for full lists of controls / indicators.)
The advantages of using the Remote include easy lens swaps (since no
follow-focus is attached to the lens), jolt-free focusing, and control
from a distance. Distance can be extended more and more by simply
extending the cable between the camera and the Remote. The Remote in
such case would be used hand-held or in various alternative
configurations like attached to video head pan bars.
The Remote can also be used as one of the hand grips of a SYMPLA rig,
meaning that one person can hold and control the rig all alone.