ATX
First off for most cameras these do NOT do Through the Lens Metering (TTLM). This means they do not automatically adjust in power to ensure proper exposure, you have to set them yourselves. Take either test shots, or use a light meter to figure out the flash setting. TTLM while nice, isnt a necessity, and for 95% of your lighting setups its going to be useless anyway. If you are looking for a flash to supplement/replace your on camera flash, and youre not using a multi-light setup etc (in other words you basically just want your pictures to be brighter!) then this is probably not a great flash. It can certainly be used that way, but it doesnt offer the point and shoot simplicity other flashes do. Get a flash specific for your camera body that features TTLM, set it up and dont worry about it again. If you want a rugged reliable workhorse flash with a ton of great features like remote activation via the built in radio receivers and transmitters, with multiple groups and remote power level setting, these are awesome. If youre good with not using TTLM then these are solid gold for a price of not much more than a couple sets of good batteries. If you want to learn lighting these are great as well, as its all on you to create your image the way you want it to. Highly, highly, recommend.