Soo... is this a no brainer?

[pagpow]

I've been shooting the Nokton a lot. The only aperture where I ever got "disturbing" bokeh in some pictures was at f/1.4, and even then it was fine in most cases. At f/2 it was fine throughout.

Now take a look at the Summicron's bokeh at f/1.4. Surprise! It only goes to f/2.

I didn't see any consistent "focus shift" issues either. I did get mis-focused shots because focusing at f/1.4 is not as easy as it seems in low light. In many cases focus shift seems to be the new Internet term for this situation.

I'd get the Nokton. It's an outstanding, consistent, sharp, small, fast and cheap lens. What more do you want?

+1 on this

I bought the nokton, was disappointed by some shots at 1.4, then noticed problem was not there at f2

google nokton 40 1.4 vs the other two lenses "rff" and you'll get some earlier threads indicating various ways in which nokton is superior, including an extensive comparison by ferider

I bought a Rokkor M 40 anyhoo, because it seemed smoother at flicker. Haven't had a chance to give it a good comparison shakeout cruise, but, in the meantime, my flicker searches did not support my earlier notion.

 

[Phantomas]

I have nothing but good things to say about Nokton. In fact it's one of the main reason's I'm keeping and shooting with my R3A. I find 40mm focal excellent and versatile for my needs and find Nokton delivers results I like. I never cared to check out another 40mm lens because of that.
No problem focusing wide open in low light either, I actually like to bring this lens to concerts.

 

[Gainsbourg]

I have a Nokton 40/1.4 SC and, if occasionally there's a busy bokeh at f1.4, it rarely occurs, and when it does it's mostly not a problem to me :





Comparatively, the extra speed stop is worth it imho


But if you think you might prefer the Summicron then you should go for it, so that you'll have no regret afterwards, this is the most important I think.