Originally Posted by Leigh B
Not meaning to quibble, but...
If you use 1:1 as the close-focus limit, your maximum lens FL is about 1/2 the bellows draw, which would be 18" in this case.
The other 2xFL (@ 1:1) is in front of the lens and is not involved in the bellows draw calculations.
Leigh, he wants to go to 3:1