July 25, 2017 Customers who have FUJIFILM GFX 50S can update the firmware of EF-X500 by updating the firmware of a camera body and attaching it to the camera. To Our Customers Using the EF-X500 Flash: An EF-X500 flash owner has reported to us an occurrence of the alkaline batteries in the flash unit becoming … Continue reading Updated: FUJIFILM to Release Latest Firmware Updates for EF-X500 Flash