Why Canon does this super slow shutter crap is beyond me i guess $$$$ and they know no matter what they build people will buy it!!! Not even 3rd party companies go beyond F6.3 at 600. The 100-500 would have been a bad as lens if it was a 1-500F4.5-5.6 but here we set at F7.1. I know the guy that had the only one in the USA to test and I talked to him yesterday this is what he told me! (Its extremely versatile, and sharp. Perhaps, not as sharp as the 100-500 at long end, but certainly capable of excellent results. It will be a gift for video!!!! Add the use of any of the AI NR and sharpening software the results will be outstanding. They will not be available for a while…I had the only one in US.). I was hoping for something other than F6.3-F9 why it couldn\'t be F4.5-F8 is flat stupid on canons part IMO, when Sigma can build a F4.5-F6.3 60-600 for the same, money. It should have been something like F6.3@600 F7.1@700 F8@ 800 are close to that. Canon is not building lenses like they use to 300F4, 400F5.6 what happened to lenses like those????? For the wildlife crowd Nikon is killing it again!!!!