Originally Posted by TekiusFanatikus
Would the EC20 (or any other teleconverter) impact shutter speed and aperture performance of any given lens? (ie. turn a f2.8 lens into a f3.5). Seems to easy to slap on one of those things to double up focal length
Oh yes, it does cost....the EC20 slows you two stops, so the 50-200 at the 200mm end goes from being f3.5 to f7.1. The EC14 costs one stop. That's why Olympus only recommends the EC20 for the faster lenses. The 50-200 f2.8-3.5 is really the end of the line in terms of what the EC20 will work with due to the aperture requirements to keep AF active.
The f2 zooms and primes, or a lens like the 300mm f2.8 are the absolute best ones to be using the EC20 with, but there are plenty of folks using it with the 50-200 and getting nice-looking results.