300mm Lens Reassurance Needed
Ok my current birds in flight set up and insect setup is the 300mm F4 IS Canon Lens with 1.4TC II on a Canon 7D. If I upgrade to the new 300mmF2.8 will I get mich quicker autofocus than my current setup both with and without the teleconverter? Also how useful is the new 300mm for insects? Could I sell my 300mm F4? Any advice greatlyu appreciated. I have read arties review of the new 300mm. But I have never seen anything about the the 300mm F4 against the new 300mm F2.8. Thanks