Have you checked out Sean Ried's review:
http://www.luminous-landscape.com/reviews/lenses/fastlensreview.shtml
As for my personal experience...
I use the Noctilux as my main 50mm lens. That is mostly because I do a lot of low light shots of people and it is perfect for that application. You gets shots that you wouldn't have otherwise. Most of my shots are of people who aren't aware that I'm photographing them.. so I'm not sure if I would call them portraits. Some are close to being portraits. Certainly the field of view is good for portraits. I've taken some lovely portraits at a wedding using the Noctilux, but I think that the aperture was closer to f2.0 for the better portraits.
Just some personal impressions of the resulting photos when the aperture is wide open (these are opinions only and not meant to denegrate the lens itself). Wide-open noctilux photos have a different feel to them.. I often feel a strange sensation in my stomach when I look at Noctilux photos.. it is almost a physical effect rather than an emotional effect (it isn't just because I have a special affection for the lens
🙂 ). Many talk about the painterly effect of the lens. The out of focus areas can look nice in some cases, and distracting in other cases. The distracting in cases are where the backround has lots of small light and dark patches and the lens paints these in a swirling pattern that can dominate the picture (I suppose this can be a good thing if you want that effect).
Benjamin Marks said:
It can be done (and I have done it), but the accuracy is a bit hit and miss (I should say that, given the razor thin DOF you might even encounter this problem on an M3).
As Ben said, focus can be a bit hit-and-miss at f1.0, but I am happy enough with the number of in focus shots.
Note that unless you are using a tripod (kida moots the point of a fast lens, don't it?) the amount that I move back and forth normally when not braced against something like a wall or a doorjamb can obliterate good focus (quite apart from the camera shake issue).
I've never quite worked out if I have this problem. At the moment I've begun using a monopod for extra support when using the 90/2.0 without the instrusiveness of a tripod. I will probably use this with the Noctilux too.
Now having said all of this, it can be done and I have done it, but the Noctilux is a big, heavy, expensive lens and you have to be prepared to get a lower-than-usal number of technically accurate shots when using it wide-open and close up.
The lens is heavy, and at first I used to get a sore wrist, but I don't notice it any more. I think that the weight of the lens probably helps reduce camera shake. The focussing mechanism is more difficult to turn than for other lenses, and the throw is longer... this enables better focussing, but it makes the Noctilux difficult to use with faster moving objects. (That said, I've used it to photograph live dancing with some success.)
A quote from Sean's review:
I would not choose to use the R-D1/Noctilux combination at large apertures for fast work in low light, but would use instead the 50/1.4 Summilux or the 50/1.5 Nokton. Though the latter two are a stop slower than the Noctilux, they allow me to focus accurately and quickly on the R-D1 and they’re much sharper, lighter and more compact.
The new Summilux 50/1.4 Asph will give you noticeably sharper shots at all apertures. I am considering whether it is worth me having the 1.4 as well as the Noctilux for those cases where f1.0 and f1.2 are not necessary. I can certainly survive OK with just the Noctilux.
I haven't looked into the CV 50/1.5, so I can't comment on it.
Phil
