Great post, electric eel. One brief comment:


Quote Originally Posted by electric eel
Btw- depth of field is 1/3 in front of the focus mark and 2/3 behind, so if you focus at 30' , the depth of field would extend from 20' to 50', this is just a hypothetical example.

That's true near the hyperfocal distance but for other distances, the DOF can be the other way around (2/3 in front and 1/3 behind), it depends on the specifics.