sooo coming back to this... i feel u on the price tags, they're seriously steep. i tried to go the cheap route too but it was kinda a headache tbh.

heres the breakdown of what i've used:

* Godox V1-O Flash for Olympus/Panasonic: The round head is cool for events and the lithium battery lasts ALL day. But ngl, i had issues with focus bracketing too—it basically just skips frames which is sooo frustrating.
* Nissin i60A for Micro Four Thirds: This one is super tiny and actually pretty reliable for TTL across both brands. Its great for macro because of the size, but the build quality is not as good as expected... feels a bit plastic-y, right?
* Olympus FL-900R External Flash: Highkey the best performance and fully weather sealed. But yeah, the cost is literally insane for most of us.

If you really need focus bracketing to work every single time, you probably gotta stick to native stuff. Its wierdly the only way to guarantee those advanced features work right. gl!

TL;DR: Use native flashes for full feature support. In my experience, swapping brands is fine for basic shooting, but unfortunately, I've had issues with the Godox V860III-O Wireless Flash—advanced features like focus bracketing basically ONLY work with native flashes. For a budget fix, grab a used Olympus FL-600R Wireless Flash for around $130. its way cheaper than the Olympus FL-700WR Electronic Flash and handles TTL/HSS perfectly on both your Panasonic Lumix G9 Mirrorless Camera and E-M1. gl!

ngl the whole Olympus vs Panasonic flash compatibility thing is basically a case of 'same standard, different dialect' - iirc both brands use the same pinout based on the original Four Thirds protocol but the firmware timing for things like high speed sync can vary between the E-M1 III and the G9. honestly if youre looking for the best value from a market analysis perspective you should hunt for a used Metz 52 AF-1 digital Flash - metz was basically the industry standard for third-party engineering for decades and their M43 units offer way more consistent TTL exposure than the budget Godox stuff you see everywhere now right? another sleeper hit is the Meike MK-420 Flash because it gives you that li-ion battery life for a fraction of the native price tag. one major 'gotcha' with the market right now is that third-party brands basically reverse-engineer the signaling so they almost always fail at focus bracketing - if that feature is a dealbreaker for your macro work you might want to look at a used Olympus FL-900R Flash because prices are tanking on the used market lately and it handles the communication protocols on both bodies way more reliably than any third-party trigger system i've tested, you know?

For your situation, compare Nissin i60A Flash vs budget Godox TT350O Mini Flash. Nissin has RELIABLE HSS for events, but Godox is lowkey amazing for macro work, right? Just watch for overheating!!

ive been using both systems for a long time and honestly im super satisfied with how well they play together for the most part. no real complaints from me on the basic sync stuff. honestly though whenever i think about my gear i always remember this wedding i shot where i accidentally dropped my entire lens pouch into a fountain. it was one of those fancy garden weddings and everyone saw it happen. i spent the rest of the night trying to dry things off with a silk napkin while the grooms uncle kept trying to explain his theory on why film is superior. he had this ancient rangefinder that probably hadnt been serviced since the seventies and kept blowing smoke in my face while i was just trying to see if my glass was fogged up. the cake was actually pretty good though, best lemon curd i think ive ever had. anyway lol sorry kinda went off topic there