Like other Panasonic lenses that bear the Leica name, this lens is a solid performer. Sharp wide open and a fast f/1.7 maximum aperture make this a great low light lens.
We've shot extensively with Panasonic lenses as part of our reviews of Panasonic cameras, and have also tested them in the lab for SLRgear. Overall, we've found Panasonic's lenses generally to be of very good quality. Helped in part by in-camera processing which reduces both geometric distortion and chromatic aberration, Panasonic lenses have consistently delivered excellent optical results in our testing and use. Lens quality is an important part of the decision whether or not to adopt a new camera system, and on that score, the Panasonic G-series does very well.
In some cases, however, there is something to be said for brand loyalty. Until recently, Panasonic cameras didn’t come with built-in image stabilization, the automated feature that counteracts unsteady hands to produce sharp images. Panasonic instead puts that technology in many—but not all—of its lenses. Olympus, on the other hand, has long offered image stabilization in its camera bodies. Their lenses, therefore, typically omit this feature. So if you own a Panasonic camera that predates the GX7/GX8-series models and want image stabilization, you’re usually far better off with a Panasonic lens. And though its latest cameras have image stabilization built-in, Panasonic has designed the cameras to work in combination with lens-based stabilization for what the company claims are improved results over using either system on its own.
There’s another cross-brand issue we’ve learned about recently: built-in UV filters. Panasonic puts the filter while Olympus places it in the lens. If you use a Panasonic lens on an Olympus body, there’s no UV filter, so in some circumstances, you may get chromatic aberration (purple fringes along high-contrast edges). This can be fixed by adding a to the front of the lens, but that’s an inelegant workaround.