http://eosdoc.com/manuals/?q=jlcalcBut, actually, I missed the point about the shorter MFD of 20 cm that I just read in the description, vs. 38 cm as stated in the
Canon specifications. Thanks for pointing that out!
Let's think about the practical implications. An MFD of 20 cm, with the Canon flange-focal distance of 4.4 cm and a lens that when extended to 70 mm focal length is 12 cm long (DPR's spec is a little longer, I subtracted for the part of the mount that extends behind the flange). So the working distance of the bare lens is ~3.6 cm, and if you put on a Canon EF 25 II extension tube (which is actually 27mm long), your working distance is
0.9 cm, i.e. to get that almost 1:1 magnification, your subject is
less than a finger-width from the front element. Yikes! H-IS for longer exposure or not, with the apparent light loss at high reproduction ratios, it's going to be pretty hard to use this lens for macro.