While the Canon 5D Mark III, 5DS, and 5DS R cameras are identical in physical characteristics, the 5DS series utilize a newer TTL flash protocol. Older housings produced originally for the 5D Mark III camera, Product Number 6871.03, will cause Ikelite DS strobes to over-expose by at least two f/stops in TTL mode when used with these newer cameras. This can be compensated for by dialing in negative EV compensation through the back of the housing, or using the strobes in manual exposure mode.
New TTL circuitry has been developed in response to Canon's change to provide proper exposure with all three camera models. The new housing product number 6871.04 for Canon 5D Mark III, 5DS, and 5DS R cameras features these updated electronics.
Strobe serial number requirements are the same with the updated housing. Refer to "Strobe Compatibility" on the housing webpage for full details.
We are pleased to provide the update of your 5D Mark III housing's electronics at the cost of 180 ¤ plus applicable freight. Upgraded housings will operate properly with all three cameras.
Please allow approximately 4 weeks plus transit time for the upgrade to be completed.