Olympus M.Zuiko Digital ED 45mm f/1.8 prime lens review at Camera Labs: This is superb performance made all the more remarkable by the tiny dimensions and relatively affordable price tag.

Gordon Laing is the reviewer, and he took the unusual step to use the Panasonic GX1 as the test camera: 

"The Olympus 45mm f1.8 is arguably one of the best lenses for the Micro Four Thirds system, whether you're using an Olympus or Panasonic body. This lens is so small and light you'll hardly know you're carrying it around, yet is capable of delivering industry-leading performance with pin-sharp details across the entire frame right into the extreme corners. With an effective focal length of 90mm and a maximum aperture of f1.8, the lens is ideal for portrait work and can deliver sharp detail on the subject with a satisfyingly blurred background behind it. Likewise for closer subjects down to the nearest focusing

distance of 0.5m. It's important to put things into perspective though: the 45mm f1.8 is a good portrait lens, but it won't match the minimum depth of field delivered by a 50mm f1.8 on an APS-C camera and especially not an 85mm f1.8 on a full-frame body. Like all Micro Four Thirds lenses, it's not just the coverage that's effectively halved by the format, but the effective aperture too, at least in terms of the depth of field. So in full-frame terms, the Olympus 45mm f1.8 acts like a 90mm f3.6 lens. You can see what to expect in my Olympus 45mm f1.8 bokeh results.

But while it won't match the shallow depth of field of portrait lenses for larger formats it will give them a run for the money - and probably beat them - in terms of uniform sharpness. As you'll see in my Olympus 45mm f1.8 quality pages, the lens is already pretty good with the aperture wide open, but close it to f4 and you'll enjoy pin-sharp results across the entire frame, right into the extreme corners. This is superb performance made all the more remarkable by the tiny dimensions and relatively affordable price tag."

Comparison: 
Selected Items
Click to close the selection preview
Compare List
Teleconverters: Click to see the selected items
Click to Compare the selected items
Flashes: Click to see the selected items
Click to Compare the selected items
Lenses: Click to see the selected items
Click to Compare the selected items
Cameras: Click to see the selected items
Click to Compare the selected items