50mm f1.4-ish lens with half stop notch before f2?

[New Daddy]

I'm looking for a 50mm fast manual focus lens (f1.4-ish) that has a half stop notch before f2.

I use a micro four thirds with legacy lenses, and f1.4 lenses seem to be too soft wide open for my preference. But at the same time, many of them don't provide half-stop notch at f1.7 or f1.8, making them non-distinguishable from f1.7 or f1.8 lenses if you were to stop down anyway for more sharpness. So I'm only willing to pay a premium for an f1.4 lens that provides a half stop notch at f1.7 or f1.8.

The reason I'm looking for an f1.4 lens although I already have 50mm f1.7 is for extra speed in dim existing light situations.

Thanks.

[aleksanderpolo]

Well, the C-Sonnar has a 1/3 stop between 1.5 and 2, but if you are looking for sharpness, this is probably not the lens for you. It's an amazing portrait lens on m4/3 though, and currently my favorite lens.

The difference in speed between 1.7 and 1.4 is basically moot. By the way, what "legacy" 1.4 lens are you talking about? Some lens such as FD 50/1.4 is really soft while other like Nikon Ais 50/1.4 is much sharper at 1.4, so perhaps you can look for a different lens?

[poilu]

[New Daddy]

[aleksanderpolo]

Even the best 50/1.4 will have lower resolution at F1.4 than an average lens at F2

http://slrlensreview.com/web/benchmarks-resources-131/98-50mm-challenge/384-50mm-challenge-canon-vs-nikon-vs-cz-jena-vs-olympus-part-3.html

So if you are going for sharpness, better stop down and get some light.
People get fast lens for their character and shallow depth of field, fast lens are more expensive as there are more aberration that needs to be corrected.

[Attila]

Adjust sharpness in your camera body , it's free... I found default settings is too soft to my taste. I did increase sharpness in Panasonic G1 and Olympus E-1 too. I good sharpening tool which is works with RAW file can help a lot too.

[std]

And the MD 1.4/50 which you already have is a very nice lens.
Get it a deep lens hood and try it.