08-13-2018 05:19 PM - edited 08-13-2018 05:31 PM
I have a 430EX (Mark I); it was never an optical master. Optical master was always kept for the 5xxEX series: 550EX, 580EX, 580EXII, until the RT series. The 430EX-RT III is an RF master. But still not an optical master.
If you want the equivalent of an S1 "dumb" optical slave mode, then then green Sonia slaves are good, but you need a sync connector of some kind to use 'em, which of course, the 430EX models have never had. It was a sport for a while among flash modders to add a 3.5mm minijack sync port to the 580EX (Mark I).
Consider trading in the 430EXII for a used 580EXII. Or a Godox TT685C (and maybe an XPro-C transmitter). The TT685C doesn't have the same on-camera capabilities or warranty service/support as a 600EX-RT. But you'll get S1/S2 "dumb" optical slave modes, as well as both master/slave capability for Canon's "smart" optical system. I use one as an optical slave/master with my 580EXII without any issues (although I more commonly use it as a TTL/HSS Godox radio slave to my 5DMkII, GX-7, and X100T).
08-18-2018 08:51 PM
Thanks, Inkista. Now that it's been a few weeks since I discovered the non-feature of the 430exII, I've calmed down a little. Not any happier about the situation, but calmer. I guess I'll hang on to it and use it on-camera. I'll also use it as an optical master for 3rd party manual flashes. But I don't believe I'll ever purchase another Canon flash.
Thanks for your input.