Review (Summary): "The word 'Pancake' in the lens's title offers a clue to its most striking physical characteristic; it is extremely thin (just 24mm, or less than 1") and extremely light, making it the perfect complement to Olympus's E-4x0 class bodies as an (almost) pocketable, carry-anywhere solution, with all the speed and responsiveness of a DSLR coupled with image quality unmatched by any small-sensor compact digicam. ...

... it has to be said that us photographers here in the DPReview studios have really rather enjoyed using this lens; it certainly makes a refreshing change from bulky SLR bodies and large zoom lenses. Ultimately this is the 25mm F2.8's strongest selling point. ..."