I am finding a conflicting issue with the DOF tutorial and its probably my lack of knowledge.
What I find odd, is that using the DOF calculator I get ....
DSLR with 1.6 crop, f/32, 200mm, 10 meter subject distance:
8.61m front focus
11.926 back focus
3.3 total DOF
Then when I change the focal length to 100mm, the DOF changes
6.05 front focus
28.78 back focus
22.73 total DOF
Then one paragraph later it says ...
"depth of field does not change with the focal length."
when clearly changing the focal length changed the above calculation.