I have a Vivitar "Auto Focus Zoom 730AFC" flash that I am wondering about. 90% of my photography is outdoors/landscape/nature and I haven't really had a "need" for a flash. I don't remember where I got the flash, I think it came as part of a "lot" of stuff I purchased. Since I don't know much about flashes I don't really have a metric to judge if it is any good. It fits on my T2i's shoe, fires when I hit the shutter, that is all I really know. Any input or advice? I don't use a flash often enough to justify spending hundreds of dollars, so will this do an adequate job for the rare occasion I need one?