Closed : Focus stacking with 7d

[ThLDQ]

Hello,
I can't understand focus stacking with my 7d.
Do you know where I can find an easy tutorial (up to date) to help me?
I've succeeded in fixing a start point ("Q" button), an end point "Set + L-R") ; (well, in fact, I guess I have succeeded as nothing tells me the start point or end point is fixed) ; but I can't understand how to decide how many pictures to take (before, after, ?).
Regards
Thierry
If someone shoots a video of a focus stacking session, it would be a great help.

[batman]

this explains the workflow:

[ThLDQ]

Thanks,
I had already watched it.
It's not up to date, not on a 7d, and it does not anwer my questions (I am on TL no more on ML, does it change anything ?).
I really need help from somebody who has got the same configuration as me (I'm a bit old now and slow brained  )
A kind of step by step guide...
Regards
Thierry