Lenses for m4/3 cameras - Short opinions about the current m4/3 lenses is a piece by Thom Hogan at:- http://bythom.com/m43lenses.htm
Lots of people have weighed in with opinions as to how right he is and have come out with their own lists. Not wishing to left out on something as much fun as that! Here's mine.
Like Mr. Hogan I haven't used them all. The Panasonic 14mm f2.8 pancake, 100-300mm, 8mm fisheye and 3-D lens are missing from the list.
SUPERZOOMS
Panasonic 14-140mm f/4-5.8
When this lens first appeared with the GH1 it seemed an engineering marvel in that it focused silently and continuously during video. Like many superzooms it tries its best to give a reasonable image quality across the range and mostly succeeds. Its not incredibly sharp but does the job. It does have the best built in image stabilisation I've ever used. I was able to get sharp pictures at 1/15th. sec. at the 140mm end, which is remarkable. It is quite a slow lens and this limits its usefulness. Also other lenses, including the much cheaper 14-42mm, and the new Olympus zooms now also have silent and continuous focusing.
Olympus 14-150mm f/4-5.6
In terms of what this will do its very similar to the Panasonic zoom. It doesn't have built in stabilisation so its smaller and lighter. I use one of these in preference to the Panasonic for that reason. In terms of image quality its very similar to the 14-140mm, perhaps just a fraction sharper, though there's nothing in it really. If you want to use a superzoom, whichever of these two you choose will be down to what the lens offers, and whether you want to use it on a Olympus or Panasonic camera. To some the stabilisation is important. Having lived without it for most of my photographic life, its not that important to me. Do be aware that the OIS in the Panasonic does little to help when you're shooting video.
MACRO
Panasonic Leica Macro-Elmarit 45mm f/2.8
This lens sometimes gets negative remarks and for the life of me I cannot understand why. Its a beautiful sharp lens. I sold mine to help pay for my Leica M9 and I've always regretted it. I may yet buy another. Its not the fastest AF but macro lenses are often like that. For some reason my copy was sharper on my Olympus E-P2 than my GH1. Don't know why that was.
This lens oozes class and is almost on a par with the 20mm f1.7 in my opinion as the best Panasonic can offer for m4/3.
TELEPHOTO ZOOM
Panasonic 45-200mm f/4-5.6
Some people rate this lens but I don't. To me its the worst lens in the entire m4/3 range. It is capable of reasonably sharp results - in my case at 100mm and f/11, but I was unable to get satisfactory results from mine, even on a tripod. I found it a very disappointing lens.
MANUAL FOCUS
Voigtlander 25mm f/0.95
Voigtlander is the third manufacturer to make native lenses for the system, and this is their first offering. If you've seen mine and others rave reviews of it you'll get some idea of its credentials. A beautifully made lens with a fast aperture, semi-macro focusing and extraordinary sharpness stopped down. I'm currently testing this on a GH2 versus a Zeiss 50mm on my Leica M9 and its really quite close in terms of results. The Leica combination is winning at the moment but not by very much at all - more on that later. Its expensive, its manual focus and its quite heavy but it is a wonderful lens if you're in the market for a very fast standard lens.
So there it is, my opinions on the current m4/3 lenses. I use a lot of alternative and legacy lenses as well but there are to my mind four excellent lenses here. Two absolute classics in the Lumix 20mm f/1.7 and the Voigtlander 25mm f/0.95 and two very good ones in the Panasonic Leica 45mm f/2.8 and the Olympus 9-18mm f/4-5.6. Ultimately how good a lens is depends on how you use it, and whether it gets you the pictures that you want. We all use them in different ways and for different purposes so its very much a personal choice.
David