Why would focus shift be different for film vs a digital sensor? I don't understand why there would be a distinction.
I haven't tried the 1.4 Nokton, and I am confused by the wide range of opinions being expressed about it, all the way from "best thing since sliced bread" to "poor preformer for sharpness, distortion, and focus shift". I did recently get my hands on an Ultron 1.7, and so far, I am very happy with it. It's not tiny, but it is small enough, uses 39mm filters, and seems well made. The only negative I have heard about it is that it is somehow "too perfect", and I have decided I can live with that.
Here are two pictures from a recent visit to the Smithsonian museum. The Lunar Module was shot at f1.7, and the castle, at f5.6.
Cheers,
Dez