Here's a quick mini review of the Vivitar DF-183 Flash (for Olympus): After trying the Olympus FL-14 and the Nissin di466, I thought I'd give this Vivitar model a try. I wanted something relatively lightweight, easy to travel with, and with a price that wouldn't break the bank. My primary usage for flash is for fill-in outdoors and occasional family photos indoors. The build quality is not exactly top-notch, but I didn't expect that for the price (~$44 on Amazon). The only really questionable construction is the locking mechanism for securing the flash mount to the hot shoe. It locks via a small push-button with tiny teeth on the side. With enough use I can see those teeth wearing down and no longer being secure. Time will tell. The front of the flash features an AF-assist lamp (useless on the E-P1), while the back panel has a "Test / Ready" button & light, On/Off switch, and an "Auto" indicator light.You can control the flash modes and flash exposure compensation via the on-board E-P1 control menu. The weight of the flash with two Sanyo Eneloop AA batteries installed is 6.30 oz. (179 g). It handles easily on the camera and even features an adjustable flash head for bounce capability.