I'm working to understand how my a6000 works in detail with the aim of (possibly) making my own LED TTL converter. At the moment I use the a6000 with its internal flash to trigger a set of YS-D2 strobes using my optical cables. I either use the strobes in manual or TTL mode. The TTL is reasonable, but not always perfect.
I wanted to understand how the a6000 TTL system works, so I connected a little oscilloscope to my hotshoe x-sync pin and used the other channel of the oscilloscope with a photodiode to monitor the flash.
See attached 2 screen grabs for two flash types - Fill Flash, Rear Sync. I also did a rear sync, but it's result was remarkably similar.
I wasn't able, in any case, either Manual, Aperture priority or full automatic, to witness any pre-flash whatsoever from the camera's internal flash.
Does the a6000 meter TTL during the exposure? Am I missing something here.
Welcome any insights, comments or suggestions to be able to run another oscilloscope test.