i purchased the Sony F43M flash to use on and off the camera as a remote WF flash. What I discovered was that the pop-up flash would not function as a commander to trigger the F43M ( no matter what B&H said on July 15). It seemed crazy to have to purchase a second flash, F20M, to do this! Today, after much difficulty (with an uninformed photography store salesperson), I was able to make a Nissin Di700a with Air Commander work with the RX10 ii!!! It worked TTL but my first shots seemed to need a little EV boost. Exposure compensation of +2 EV was a little too much so I am sure that all will be well. I will sell the new F43M or use it as a second remote flash with my Nikon. An in-store vendor here in London sold me the Nissin unit for €170 so I believe a much better price could be had online - I felt bad for taking up at least an hour of his time to get the unit working. READ the instructions carefully and follow the sync steps EXACTLY and it works fine.