8 out of 10 points and recommendedgood magnification factor, sharpexpensive, only works with pro lenses
I have found this to be an excellent compromise between a 1.4 and a 2.0 TC. I didn't think that the 1.4 added enough focal length to be worth it, despite the excellent image quality. The 2.0s provide more focal length, but cost substantially in both light and sharpness.reviewed December 5th, 2006 (purchased for $400)
This TC is an excellent companion to my 70-200VR. The reduced sharpness is barely noticable; if I stop down to 5.6 or so I don't see it at all. Going from 200mm to 340mm, though, often makes all the difference. I have used it shooting both animals and sporting events where a little more reach was required, and have always been pleased with the results.