I'm not really concerned about Photodo scores, all I know is that the Canon 180mm delivers in trumps for this application. [a href=\"index.php?act=findpost&pid=57445\"][{POST_SNAPBACK}][/a]
You should be because there's more to know than that. I've just checked out the Photodo procedures and, as I suspected, they test lenses only at infinity. Now you might criticise them for this but the fact is, for each prime they will take at least 96 measurements. (0, 3, 6, 9, 12, 15, 18, & 21mm from the centre, all at 10 lp/mm, 20 lp/mm and 40 lp/mm and all at the 2 f/stops of f8 and maximum aperture.
For zoom lenses it's more because they test at a number of different focal lengths. For their test of the Canon 100-400L IS zoom I calculate they would have taken 384 measurements.
Now I know that a seasoned professional who has worked with a lens for a while will have a pretty good idea as to its performance under a variety of conditions and will discover attributes that are not even addressed in Photodo MTF charts. However, it's interesting that in this thread no-one has mentioned that the 180/3.5L does not have the same stellar performance at infinity that it has at close focussing distances.
The only clues that this might be the case are the Photodo tests. Now this might not be of concern to those who bought this lens specifically for portraiture or macro work, but that's not its only use. Because of its extremely flat MTF response right out to the edges, some might think this lens could be an ideal choice for panoramic image stitching. A group of 16 stitched images with this lens could make an equivalent 4x5" format shot look like a 3MP P&S blow-up, by comparison.
Checking the Photodo MTF charts again, it seems that the 180/3.5 macro at f8 has an almost identical performance to the 100-400 IS zoom at 180mm and f8 (at infinity of course). Now this is worth knowing, isn't it? How long would it take a seasoned professional with a bunch of lenses to discover this fact?