I use the histogram alot when shooting outdoors and it's hard to see your picture because of the glare. I check the histogram to make sure I'm exposing it properly. It's a very helpful tool once you learn how to read it. Well worth the effort to understand it better.

I know my Speedlite 900's will work off camera with my on-camera flash serving as the remote signal, but you have to make sure there's nothing between you and the flash for it to activate. I need to get a remote that can be attached to the hot shoe and will activate the off-camera flash no matter where it is. I'm a wedding photographer and that can pose a problem at times with so many people milling about. Thanks for any suggestions. :D

As far as I know, you have to use your on camera flash to activate your Speedlite flash. It serves as the remote for the off camera flash. Hope this helps.