Need small, fast, normal lens for NEX advice

[saintz]

I am looking for a lens that is "normal" focal length, between 35mm and 60mm or so, fast (f1.5 or wider), and preferably small. For use on a NEX 3. Bonus points if it also works on a Canon EOS FF camera.

I am debating getting a Nikon 50 or 55 f1.2, which will work on both the Canon and the NEX.

Or I could go with a smaller/cheaper lens for the NEX, like a:
Olympus PEN 42 1.2 (probably too expensive)
Olympus PEN 40 1.4
Jupiter 3 50 1.5
Canon FL/FD 50/55/58 1.2 (big and doesn't work on EOS)

Will the PEN or Jupiter lens be a real advantage in size over the Nikon f1.2 lenses? Is it better to shoot for lens compatibility across both cameras, or buy specific lens for each? Compatibility reduces the number of lenses, but increases the size and cost of each lens.

[DigiChromeEd]

Olympus OM 1.4/50mm.

[saintz]

[DigiChromeEd]

[Attila]

I have no experience with Pen lenses, my guess they are not better than SLR lenses.

I have three copy of J-3 and several times I had OM 50mm f1.4 if size is serious factor go with J3
they are good as than any top lenses stopped down for sure. Wide open performance is a bit vary, some
of them sharp , some of them has 'leica glow' = litle soft

From all OM 50mm f1.4 is cheapest option and really good option.

[fermy]

[hoanpham]

Voigtlander 40/1.4 in Leica M mount.
Tiny, fast, sharp even wide open.

If I need small and light weight, this lens is one of 3.
The two other are Zeiss Biogon 28/2.8 and Sonnar 90/2.8, both in Contax G mount

[Lightshow]

I can speak to the Pen-F 38/1.8
It's compact, sharp from WO, it's only weakness is it's flare resistance.

for both NEX & EOS:
The OM 50/1.8 MIJ is superb, it's shorter than the 50/1.4 and super sharp.
Super-Tak 50/1.4 or 55/1.8 are nice.

I also have a Canon RF 50/1.8 that I like.
I'm looking at getting the CV 40/1.4 Nokton, I really want the 38/1.2 Nokton but it's size and price are keeping me from pulling the trigger.

[kuuan]

Pen-F f1.4/40 definitely, a little gem, lately my most used lens.

the Voigtlaender must be great too.
other than that the Olympus made for SLR as suggested, the f1.8/50 is the smallest, if Pentax / Takumar the Pentax M f1.7/50 is very small too, next would be M f14/50

[estudleon]

Summilux M 50/1,4. Summilux M 35/1,4 old style.

[Phenix jc]

"normal" is 35mm in APS-C. 40mm is the long end. 50mm & 60mm are medium long lens.
Go for Leica Mount for small. Small is beautiful. Voigtländer, Zeiss...Leica (& others)
The 38/1.8 Pen F is a killer though

[estudleon]

The rare pankake normal lens for pen f is another good one. It came, as option, with the ft black.