Since I'm a Canon shooter, I've got a few EF lens and I adapt them to my Olympus E-P1 with a Fotodiox EOS to Mu43 adapter.  There is no communication between adapted EF lenses to the E-P1, meaning no AF confirm and no aperture control.  Not an issue with me on both counts.

The 70-200/4 L may be Canon's 'cheapest' L lens, but it is perhaps one of their absolute best zoom lenses.  IQ, contrast, micro contrast, colors and sharpness are superb from wide open.  It is honestly like having 130 primes, albeit slow primes.

The 70-200/4 L adapted to an Mu43 body will give you zoom of 140mm-400mm when applying the 2x crop of the sensor, so this means keep your shutter speed up at long focal lengths.  The zoom mounted on the Oly has an odd, unnatural balance.

Image results of the pairing are simply great, as long as you keep that shutter speed up and or use a tripod.  Which leads me into my other use of this pairing; simple astrophotograpy.  I get great results using the Canon 70-200/4 and E-P1 coupled with a Kenko Teleplus Pro DG300 2x teleconverter.  This trio gets me a nice 400mm focal length, which translates to 800mm in a 35mm conversion.  That is a lot of reach for $1100 (lens, Oly, adapter and TC).  The Canon EF 800/5.6 L is $12K.

E-P1 w/ Canon 70-200/4L


Sample images to follow...


Jason C 

E-P1, Canon 70-200/4, 200mm fl, full frame image, with 100% crop to follow (sharpening was applied):




Just added an un-sharpened crop:



Jason C

Astro-photography with E-P1, Canon 70-200/4 L, Kenko 2x tc and tripod.  All fl are 400mm, and all are f/11 and cropped half frame:





E-P1 and 70-200, no TC attached and nearly a 100 pct crop:



Link to my Jupiter captures with the ubove set-up: http://e-p1.net/the-photo-book/jupiter-and-the-e-p1/



Jason C

E-P1, Canon 70-200/4 L, 200mm fl and f/4:





I will try to get some portraits with this setup in the future.


Jason C