I currently own Nikon DSLR's and lenses. I am thinking about getting into either a Contax or Leica system. I will be scanning the film from any of these systems. Anyone have any experience with these two systems? My Nikon lenses are sharp, but I want "that extra edge" or the legendery sharpness Zeiss and Leica is known for. Is it worth the investment or should I stick with my Nikon lenses and just be content? Which are sharper, Zeiss, Leica, or Nikon? (primes and zooms)
You would be spending a LARGE amount of money to get an almost imperceptible gain in image quality. Nikon lenses when stopped down even moderately are just about as sharp as you can get. Try using a tripod EVERY shot for unbelievably sharp results. The tripod and cable release are the original IS (Image Stabilization). No kidding, when you use a rock solid tripod you will get results that will AMAZE you! It takes some real discipline to use that tripod, but it's worth it!
Across the complete system, the Leica probably offers the best, although each system has it's highlights. For example, at 24mm, the Nikkor lenses are probably the best. At 35, probably the Leica. At 80-85-90, all 3 vendors have good options (as is the Canon). The Leica 28-90 vario elmar is the best mid range zoom available, which it ought to be at $3500+. The Leica system is also fairly consistent for color and contrast; one of my problems is figuring out which lens shot what. With Contax, other than mounting the lenses on a Canon with an adapter, you have no viable option for a digital body. Leica is still in business, and you've got the DMR as an option.
On the other hand, you might find that your Nikon's are "good enough". I've mostly switched to the Leica/DMR from Canon (and 25 years of Nikon before Canon), but I'm not sure the change is "worth" it.
If you want to have the best quality in 35mm film go to the Leica M mount, Leica, Zeiss-Ikon or Bessa with a mix of ZM and Leica lenses.
The Contax/Yashica is history, the lenses are sometimes better than LeicaR and sometimes worse than Nikon. There will be nothing new coming out, just an option if you want to pick up some cheap gear with good glass.
The rumors I have heard are that Leica lenses are sharp when used wide open, unlike Nikon which provide better results stopped down to F8 or 5.6. I have found that I do get better results with my current lenses when used at 5.6 or 8, but I find this to be dissapointing. After all, why bother buying a "fast" lens if you will not get the results you want when using it wide open. For example, my three favorite Nikon lenses are my 17-55mm 2.8, 85mm 1.8, 180mm 2.8. Theay are great lenses but you have to use them on their "sweet spot" between f5.6 and f8. I would love to shoot with them wide open and get the same results as if I had shot in f5.6 or f8! My theory is that why did I pay more money for these lenses instead of getting some slower, less expensive lens that could be used under the same lighting conditions? There are plenty of wedding shots I would love to take without flash and not have to increase my ISO to 800 just to get a good exposure. My D1X is great when it comes to low noise, but I would love to shoot at an even lower ISO to get sharper, less noisy pictures even if it means using ISO 400 film and scanning it. Again, I have never used Zeiss or Leica lenses so I am only going by their reputation. I might be painfully wrong about this whole thing!
Many times wide open used as much to control DOF and so maybe edge sharpness not so important in Nikkors and cannons.
However, coming from much Zeiss glass (and some Leica like 35mm) I recently rebuild my Leica lenses. They are much different in contrast, color and bokeh. Zeiss still leader in sharpness and detail (but I have MF)
And of course, much more useful edge to edge (but so far with 1.3 crop on DMR!)
But BIG bucks for the leica look.
As other posters have explained, for 'sharpness', many of the Nikon lenses are already superb, rivalling the best available. Zeiss and Leica offer different advantages, but aside from some noticeable real world resolution gains in wide open performance (Leica) or superior microcontrast at smaller apertures (Zeiss), or richer colour rendering (either) the primary difference is in the drawing style of each lens.
Nikon lenses on average are characterised by a 'brittle' kind of sharpness and - in some cases - distracting bokeh. Blue rendering is usually very strong, so good for skies.
Leica lenses have beautifully open shadow rendering and a distinctive 'creamy' look, especially in defocused areas. Colour is generally very neutral, and moderately vivid. Resolution is generally high, though relatively not very contrasty. Wide aperture performance is peerless, and the quality of the bokeh is only equalled by the best Zeiss optics.
The Zeiss range features strongly saturated colour, a distinctively limpid 3D rendering and very high microcontrast and resolution. Most Zeiss lenses perform at their best 1-2 stops down from their Leica equivalents. It is often true that Zeiss lenses look better at f11 than their Leica counterparts, but are outperformed by them at f2.8.
Much of your decision will be subjectively based on your preferred 'look' and shooting style. But be warned that falling in love Leica-style will empty your wallet a lot faster . . .
If you want truly great "wide-open" performance Leica is the game. Zeiss lenses are designed for best performance at 5.6 and above. Leica lenses are just the opposite. In fact the fabled Leica 100 2.8 macro actually sees a degradation in performance beyong 5.6, but at 2.8 is about as good as it gets and right to the corners. Different horses for different courses. If you go away from the Nikon the best best is to get a Canon and pick and choose your lenses. I did that and still continue to use the Nikon 17-35 zoom (about as good as a wide zoom gets), Zeiss 21 2.8 (the best of the best) Leica 28-90 zoom (best of the mid range zooms) and a variety of other primes. Adapters are available for all three of these systems and others as well (Pentax, Oly etc). Frankly, unless part of your hobby or work requires ultra wides (the Nikon 14mm stinks) or you just like the search part of the hobby, your Nikon system should serve you well and you have no worries about when they are going out of business
Speaking generally, Nikon has no problem delivering sharpness. My gripes are excessive lateral color, and bokeh. The all-too-common jagged background (ni-sen boke-aji) drives me batty. There are exceptions like the E Series 50/1.8, and the classic 105/2.5. My entirely subjective grading for bokeh...
D - Nikon
C - Zeiss (C/Y mount)
B - Canon
A - Leica
I don't have experience with Minolta but, based on Web images, would probably grade them an 'A'. They were a partner of Leitz for SLR bodies and optics, and innovated with circular apertures, SLRs with STF mode, optical designs attentive to OOF rendition, and apodization filters (135 STF). I just inspected a japanese site for the Minolta TC-1 P&S:
The 28/3.5 prime generates an amazing OOF smoothness, and the highlights are actually circular, thanks to an old technology called Waterhouse aperture stops (an actual circular mask rotated into the optical path). The same site shows the bokeh from the Contax T3 (CZ 35/2.8 lens) and, much as I enjoy this camera, the bokeh is quite underwhelming.
