Hi All,
Just a quick response to comments made after my inital post (above). Yes, the rule generally observed for most lenses (years ago) was DOF fell 1/3 in front of subject focued on and 2/3rds behind.With modern optics and different design and optical parameters being part of the lens manufacturers's objective, I have found this observation to be less and less true for many lenses (but not all)...especially when wide open. This is clearly not the case with "some" of VC fast glass nor with certain Leica lenses. Just look at the Lux 35mm f1.4 ASPH...a properly adjusted sample front focuses quite a bit wide open where the subject is placed at the very back of the depth of field.... to compensate for the backward focus shift observed when the lens is stopped down. As a consequence, the background is beatifully soft and difuse.
Please keep in mind that my observations with the Nokton 50mm f1.1 vs. the Noctilux 50mm f1.0 was done on an M8, so the crop factor has to be taken into consideration when mentioning other optical differences that might be seen on full frame, especially in the corners. Still what struck me is the incredbale similarity of the two samples I had, as though VC was trying to emulate the Leica Noctilux...but at the same time address difficulty of focusing wide open by having the subject being focused on, put more squarely in the center of the depth of field rather than the Leica, which puts subject more towards the rear (of depth of field), therefore isolating the subject by having the zone of focus end just behind the subject.
The same observations were made with VC's 35mm f1.2 vs. Leica's 35mm f1.4 ASPH.
The Nokton is more of a neutral lens and as such, doesn't have what some would refer to as a "signature", which can be quite different than the Noctilux, especially under certain lighting. This is why for some, it is somewhat unexciting or doesn't move the viewer as much as say the Noctilux. My shots didn't incorporate bright front, side or back lighting and it's with these conditions that I suspect more of a optical "signature" will be observed between these two lenses....and the benifactor of this kind of lighting will most definitely be the Noctilux! Under fairly evenly lit subjects, where lighting is netural and of moderate contrast, it's here that these two lenses seem quite remarkably similar, not only as I described, but in resolution both center and corner. Even their bokeh under these netural lighting situations was remarkably similar. They though are no match, even resolving power wise, at f4.5-f5.6 for a lens like the current Summicron 50mm f2.0 or VC's own 50mm f1.5, where both those lenses wide open and stopped down far surpass the resolving powe in both the center of the image and especially the corners (all observed at 100% examination). It was the corners where the differences could really be seen. Keep in mind, as stated below, these observations were at 100%, so it depends how large one prints (or pixel peeps) that will be a factor whether these differences are important.
Lastly as we all know, different samples of each can focus differently as well as the camera (such as an M8) might....so these observations have to take these facts into consideration too...although I did observe the same on a second M8 correctly focusing body.
Dave (D&A)