So, if you get the Cactus triggers and some third party flashes, and go full manual, how do you know what level of flash to use without a TTL setup to tell you? Is it a lot of trial and error? Or are there hand-held meters to help out? I guess what I want to know if there's any way to meter the upcoming flash, and adjust it fairly accurately before taking the shot. If you do use mostly trial and error, how do you prevent from flashing the hell out of your subjects and burning through batteries? Or, once again, is that just part of the learning curve process? I'm just getting into this, and have been learning about the gels, and the setups and stuff. Just wanted to know how hard it is really to start using a manual setup. I'm sure it really doesn't matter once you know what you're doing.