From the OM system 35mm SLRs and lenses to the XA series rangefinders and the half-frame Pen models, Olympus has for at least half a century been notable for producing cameras that are smaller than their competitors without sacrificing quality or functionality. And they haven't stopped; the E-450 and its predecessors are still the world's smallest digital SLRs, and the new E-620 is considerably smaller than similarly specified competitors (finally realizing the 'smaller format, smaller camera' promise we were all sold on when Four Thirds originally launched).
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