Canon finally makes an *f4* 70-200 IS...

"Bill" wrote in message
...
The thin black line is wide open at 30lpm, which shows fine detail
resolving power or sharpness. It's only 65%, not very good at all. It
shows an odd hump beyond 15mm but that doesn't really matter.


The "odd hump" beyond 15mm is what allows the 70-300 to be sharper than the
70-200 at that part of the frame in that condition. The 70-200 gets softer
toward the edge while the 70-300 gets sharper. Obviously the 70-200 is the
overall better lens, but it isn't sharper at every part of the frame both
radially and tangentally. The 70-300 has the odd characteristic of getting
sharper when wide open toward the frame edge. I was merely pointing out
that you can construct a test where the 70-300 will score better than the
70-200 since the 70-200 doesn't have better mtf at all positions.

"Wolfgang Weisselberg" wrote in message
...
Be aware that Canon's MTF charts are computed, not measured.


I didn't know this. I presumed that they either measured one sample, or
averaged a whole bunch of samples.