I basically bought the lens because of how much Alan has raved about it. I wanted it for butterflies in the summer and I knew it would work for birds in the spring, when they're really close in some of the parks. I've used it for butterflies at the minimum distance with the extender, shooting at 560mm F9 and it's extremely sharp. You can see all the detail you're looking for, individual strands of hair on the butterfly body or veins in the wings. You will not be disappointed with it. I got mine from a Canon refurbished sale and it was only $1500, which also made it a no brainer.you are getting me convinced about 100-400 .is it as sharp when 1 meter bug shoot too?
Been trying shoot bugs with 40cm focus distance and its difficult when bug is awake and observing dangers.
Macro lenses must be good only for sleeping and dead bugs.
Awesome thing you can change bug shooting to bird shooting just with turning mode button