Yes and no but mostly no. A Panasonic G3 with 12-35 f/2.8 weighs 1 lb 9 oz, that's less than Canon's equivalent 24-70 f/2.8 by itself and only a little more than Canon's 24-70 f/4 or 24-105 f/4. I like what Canon has done with the camera but the good lenses will continue to be large and heavy. Even Canon's EF-S 17-55 f/2.8 (a good lens for the SL1) is well over a pound. Funny enough, the next gen of Panasonic micro 4/3 is rumored to be larger than the current models.