So I've long been a fan of the micro four thirds format. But for a long time now it has been lacking a good portrait lens, with fast aperture. Enter the Olympus 45mm f/1.8 micro four thirds lens. I have had it for over a month now and use it on my GH2. This lens has completely changed how I am going to use cameras going forward. Here is the run down:
1. Size. This is a very small and lightweight lens. The smallest and lightest Canon lens I've ever used is the 50mm f/1.8 plastic lens, and the Olympus is ever lighter and smaller than that.
2. Focal Length. The 45mm focal length gives a basic field of view of a 90mm lens on a full frame camera.
3. Aperture. F/1.8 is fast enough for me. It is quite sharp at f/1.8 or f/2, much more so than any Canon prime I've owned except for macro lenses. This lens is very similar to my 60mm f/2.8 Canon macro in terms of field of view, background blur, etc. At f/1.8 it won't blur the background quite as much as a similar full frame lens, but I find this is a bit of a blessing - I rarely actually want the shots where one eye is in focus - I want subject isolation, not dreamy pictures.
4. Focusing. With the MSC focusing it is very fast to focus, as well as being near silent in movies. It works well with tracking on my GH2, delivering in focus shots of my kids riding bikes towards me and so on.
5. Price. At $399 it is a good value compared to similar primes in other formats. The Canon 85mm f/1.8 is a similar lens on full frame, and has more problems wide open than this lens. Build quality is not as good, but it still feels solid and like it will last a long time.
In terms of stock, I've had no problems getting images taken hand held in low light approved. As with any format, it ultimately comes down to the lens selection. I personally prefer more telephoto shots, and with the addition of this lens I'm happy!