Thanks for sharing, my friend, your post is really useful and enlightening. Covering the viewfinder is something I've learned from my mistakes, also. Still have to try bulb in an effective way, though. I'm a bit lost in using it. I would add also in your awesome post the blocking of the mirror, at least I do this on my camera when I use my tripod, although I don't know if all DLSR cameras have this feature. Thanks again!