The two lenses each have their comparative strengths and weaknesses. On axis, the Olympus is sharper. It has less falloff, and controlled color fringing better. It works on Four Thirds DSLRs as well as Micro Four Thirds cameras. The Panasonic has better resolution in the corners and shows less flare. It's smaller and less expensive. We'd say that post-processing images from the Panasonic will be easier – if only because there's no way to recover the resolution that the Olympus loses in the corners.

All told, the Panasonic is generally a better choice. We say that partially because of its performance, but mostly because of its size and price. We'd use it rarely, so we'd have a hard time justifying the extra size and cost of the Olympus. Photographers who don't have a Micro Four Thirds camera would clearly have a different calculation to make.

It seems fitting to wrap things up with an observation we made earlier – we wouldn't use it unless it were the only way to get a shot we needed.