100-400 vs. 70-200/4 detail

[planesh00ter]

I shoot a lot of plane pics. I swear I can tell the 200mm shots with the smaller lens vs. the goliath. They are always in focus while the 100-400 are 60% of the time. I use the center focus point so I don't get influenced by the ground. Anybody see a problem? I am getting tired of the big$$ not comming thru. I need to do a test , but thought I'd ask.
That 70-200/4 is a damn clear little lens !!!!!!!!!!!!!!!!!
cheers

[timmyquest]

I shoot a lot of plane pics. I swear I can tell the 200mm shots with the smaller lens vs. the goliath. They are always in focus while the 100-400 are 60% of the time. I use the center focus point so I don't get influenced by the ground. Anybody see a problem? I am getting tired of the big$$ not comming thru. I need to do a test , but thought I'd ask.
That 70-200/4 is a damn clear little lens !!!!!!!!!!!!!!!!!
cheers

The 70-200 f/4, f/2.8, f/2.8 IS are pretty much considered the sharpest zoom canon makes. So it is no suprise.

And FWIW many have said the f/4 version is the sharpest of all of them.

[tpinchback]

post some examples of the 100-400 not being sharp with the exif please