I was using a D700 with 14-24, 24-70 and 70-200 until last november and even though I was very satisfied with the noise-free images, I constantly lusted for more megapixels. So I sold everything and decided to switch to Canon but since the 5D II was not then available I ended up with a 1Ds Mark III and three lenses, 16-35 II, 24-70 and 70-200/2.8 IS. As a longtime user of both Canon and Nikon systems I can provide a neutral perspective:
After two month and considering the financial loss I probably should have waited for the D3x, but in summary I don't regret having switched systems. In my view the handling of the 1DsIII is much better than the D700 (or the similar D3, which I tested), but this is just personal preference. I especially like Canon's clear button layout instead of Nikon's sometimes confusing dials and switches, the large back wheel and the huge 100% viewfinder (noticeably bigger than that of a D3). I don't care for the coarse grained LCD of the 1DsIII but it does its job of showing the histogram as well as the high-res screen of the D700. The metering is definitely more conservative with the Canon, preserving highlights much better, even with HTP off. I constantly had blown-out highlights with the D700 and since the metering was very inconsistent, I couldn't set a global compensation.
Comparing the high-ISO capability of the 1DsIII with the D700 I think the difference noisewise is usually greatly exaggerated and only about one stop worse. I can live with that. I've recently did a comparison with a D3x and yes, at ISO 100 the deep shadows are noticeably cleaner with the D3x than with the 1Ds, resulting in about one EV more headroom for fill-light. But the resolution and the noise at higher ISO seems to be about the same. Compared to the D700 the resolution of the 1Ds III is definitely much higher and the dynamic range is about the same.
- I didn't like the famed Nikon 14-24 that much, for it's focal range is too limited. Also it's heavy and doesn't take protection or polarizing filters. Its optical performance wide open was superb though. The much cheaper Canon 16-35 II positively surprises me with low CA, good corner sharpness stopped down, low weight and a much more useful focal range.
- The Nikon 24-70 had high distortion and too much CA. The canon 24-70 lens is a little less sharp wide open, but all in all I find it slightly superior to the Nikon.
- The Nikon 70-200 is just disappointing, showing unsharp corner performance even stopped down to f16. The equivalent Canon lens is nearly flawless and I also appreciate the shape and the gray color ;-)
With the latest tilt-shift lenses Canon has just become even more attractive ;-)
Regards,
Matt