Which Yongnuo flash is compatible with an Olympus Pen F? Do I need to purchase Yongnuo triggers to use the flash? I currently have other brand triggers and would like to use those.
4"other brand" ... mentioning precisely which triggers might be useful...– TetsujinJul 31, 2018 at 17:23
2Also, define "compatible". As in "doesn't fry my camera" or "works just like an Olympus FL600R would on the hotshoe", or "fires off-camera" or...– inkistaJul 31, 2018 at 20:38
1See also: How compatible are different flash brands for remote control over the flash? and Is there a radio flash control system for Olympus that allows setting flash power from the camera?– inkistaJul 31, 2018 at 20:40
Which Yongnuo flash is compatible with an Olympus Pen F?
None of the Yongnuo flashes will fry your digital Olympus mirrorless camera. But none of them are fully-compatible with it, either. Yongnuo at this time only makes TTL/HSS gear for Canon and Nikon (with one TTL/non-HSS flash for Pentax). Their manual-only gear can be used with Olympus, but there is no TTL, HSS, 2nd curtain, etc. capability. Just firing in sync, and (possibly) remote power/zoom control, if you use Yongnuo manual-only flashes with built-in radio triggers (YN-560 III, -560IV, -660, -720), and the corresponding Yongnuo transmitter (YN-560-TX).
Do I need to purchase Yongnuo triggers to use the flash?
If you want remote power/zoom control, yes. You need to use the YN-560-TX and the Yongnuo single-pin manual flashes with a built-in radio trigger.
I currently have other brand triggers and would like to use those.
You can use them with Yongnuo flashes, but then all you get is firing the flash in sync.
I would highly recommend (at the time of this writing) that you consider, instead, going with Godox gear (both flashes and triggers). With a TT600/X1T-O combination (which costs roughly the same as a YN-560IV+YN-560-TX combo), you not only get remote power control, but also HSS from an Olympus camera. With a Godox TT350-O or TT685-O, you'd also have remote TTL and zoom control. Godox supports micro four-thirds as a system, and the expansion options are much better than Yongnuo's.