Using a separate shutter cable with Promote Control offers the following benefits:
Enables Mirror Lock-Up functionality
Allows automated exposures longer than 30 seconds
Ensures faster camera reaction to shutter release, especially in "High Dynamic Range" mode
Activates "Manual Hold" mode
Enables arbitrary shutter speeds in "One Shot" and "Time Lapse" modes
Allows pre-focusing the camera using the Promote Control "Focus" button
Enables basic Promote Control shutter release functionality even when out of battery power
NOTE: Canon 5D Mk I is not supported by the Promote Control HDR mode. Only a limited subset of basic features such as One-Shot, Time Lapse and Manual Hold are possible on a 5D Mk I, and would require a CN3 cable to be connected.
Guaranteed against defects in materials and workmanship for a period of one yearfrom the date of original retail purchase.