About 2 years I used different 50mm lenses. Canon EF 50 1.8, Nikon 50 1.4, Canon FD 50 1.4, Canon FD 50 1.2, and finally Zeiss Plannar 50 1.4 (Nikon and Canon versions).

Zeiss Plannar finally was the best 50mm lens, lot better than FD 50 1.2 (yes even bokeh at Zeiss was better than FD 1.2).

Olympus 45mm 1.8 optically is perfect, very close to Plannar, and without flares of Zeiss. But bokeh of Olympus far from Zeiss, so I always prefer 50mm.

I sold Plannar 50 1.4 for Nokton 42.5, it very best of all Noktons, really, very good at 0.95. But I feel I miss 50mm (100mm look of full frame) it just more close-up lens.

At MFT small length difference gives just another lens look. 42.5mm is not equal to 50mm.

the same sort of size as my 50mm Canon FD 1.4

Generally it is biggest problem. As 42.5mm and 50mm are not big difference on m43, usually you can replace one with another.

http://digicame-info.com/2013/11/nocticron-425mm-f12-3.html

Will be interesting to compare to the Olly 45. I would actually prefer 42.5 as a focal length, even though they are close, and the 1.2 would be very cool. I can't see owning both, so if this is better, the Olly must go.

Wondering how the aperture ring works on the 42.5, by wire like focus? Mechanical? Are there other pany/oly lenses that have this?

Nikkor 55/1.2's optical performance will likely get beaten by far, as it doesn't really get contrasty before f5.6 or even f8 on FX, but its image on the microFT sensor is totally diffracted then already.

It is very exciting that the Pana introduces OIS with this ultra fast 42.5mm prime lens.

I dont get it ...42.5mm?... Is there a significance to an 85mm equiv in terms of FOV?.... Am I nuts or is this not super useful? ---for video I mean-- Headshots I can image would look nice.

And the first M43 lens with aperture ring

When everyone must watch the voigtlander 0.95 to have light, panasonic introduces this f1.2 and let me say, it's over. The ois in lens is a must!

Still want the 17.5mm NOW!

I hate the X lens labels.

@stonebat Of course but if you can set focus points in a phone app and only need to push them to make the lens focus to these points, if could replace a follow focus (that wouldn't work very well with fly-by-wire-lenses)

@RRRR Good idea! I was also disappointed these are fly by wire again :/ As if nobody would actually use manual focus…