The Setup
The Leica M8 and Nikon D700 are certainly not what you'd call "similar" cameras. The former is a 1.33x crop sensor digital rangefinder camera, while the latter is a full-frame pro-spec DSLR with the full complement of bells and whistles. So why compare? Simply because I wanted to see how the image quality of these two cameras compared at their base ISO settings: 160 for the M8, and 200 for the D700. At ISO settings above about 800 the D700 can't be beat, but the M8 puts out some gorgeous files in its optimum ISO range. I was expecting the D700 to have the edge even at base ISO, simply because it is a much newer camera that features the latest full-frame sensor technology. To test out that assumption I made up a little still-life scene and captured equivalent images with the M8 and D700 – well, as equivalent as I can get them. The details are ...
Leica M8
Lens: Zeiss Planar 50 mm f/2 (35 mm equivalent = 66.5 mm) with B+W UV/IR filter
Exposure: 1/250 sec. f/8. ISO 160
Nikon D700
Lens: AF-S Nikkor 24-70 mm f/2.8 G ED (@ 66 mm)
Exposure: 1/250 sec. f/10. ISO 200
Lighting was with a pair of monoblock strobes. Both files imported directly into Adobe Lightroom with only WB matching. No other adjustments were made (not even straightening or cropping). The files were exported from Lightroom as jpegs with a quality setting of 75.
* Note 1: Keep in mind that fact that the Zeiss has a maximum aperture of f/2 compared to
the f/2.8 of the Nikkor.
* Note 2: The exposures were bracketed, and the images shown below were chosen for their equivalent
histograms. Specular highlights on watch, pens, and blue vase.
*Note 3: Focus is on the snap button on the bag pocket flap nearest to the center of the image.
The Images
Obviously these small jpegs aren't going to tell you a whole lot, so you'll have to take my word for some things. But if your initial impression is that they look very similar, your initial impression is correct.
Leica M8, Full Scene
Nikon D700, Full Scene
Here are a couple of 100% crops from around the focal point of the images. The difference in cropping is due to the difference between the 10 and 12 megapixel (approx.) sensors, and should probably be left as is in order to provide true "100% crops."
Leica M8, 100% Crop
Nikon D700, 100% Crop
My Personal Conclusions
In terms of pure image quality at base ISO, this is a mighty close race. There is an obvious difference in contrast (the D700 is a bit snappier), but I'm pretty sure this is a lens issue rather than camera or sensor. The Zeiss Planar is a mighty fine lens, and this comparison reinforces the findings of others who have pointed out that the AF-S Nikkor 24-70 f/2.8 is indeed an amazing zoom. One noticeable difference is that he D700 seems to have reproduced the color of the dark green bag lining a bit more accurately than the M8, and this may be due to some residual IR contamination. That might change if a Leica UV/IR filter is used rather than the equivalent B+W product.
But in general – and this is the surprise – I'd have to say that at these ISO settings the difference is, for my purposes, pretty much negligible. This is very good news because the M8 is lighter, more compact, and more discreet, and I'd much rather use it for many applications. The most significant differences in favor of the D700 are incredible high-ISO performance (it leaves the M8 in the dust at 1600 ISO and above), fast auto focus, zoom, outstanding AWB accuracy ... and all the other features that make a DSLR a DSLR. Relatively fast continuous burst rates and live view don't mean a whole lot to me at the moment, but you never know when things like that might come in handy.
So it looks as though things have worked out as planned. When I need to go to work, the D700 will be the camera I grab. But for pleasure or just general digital shooting the M8 will remain my instrument of choice.