The whole thing made me curious about the equivalent images that can be attained with the D300 and D700 paired with higher end Nikkors. The pairs of images below were all hand held. The images are not "strictly" equivalent since I used aperture priority with auto ISO set according to focal length, and with two stops shutter speed compensation for lenses with VR. So at a focal length of 130mm on the D700 with VR lens, I set the minimum shutter speed to as close to 130mm/4 as possible. Whereas at 85 mm on the D300 with a non VR lens, I set the minimum shutter speed to as close to 85mm*1.5 as possible. The top ISO before violating my minimum shutter speed requirement was set at ISO 3200 for the D300 and ISO 6400 for the D700. I tried my best to frame the pictures similarly.
Nikon D300, Nikkor 85mm f/1.4D, f/2, 1/80 sec, ISO 280
Nikon D700, Nikkor VR 70-200/2.8G, 116mm, f/3.2, 1/20 sec, ISO 200
The VR 70-200mm f/2.8G and the 85mm f/1.4D are both awesome lenses. If you compare the two images you can see a little bit of the vignetting on the 70-200 image, but it wouldn't otherwise be noticeable. I had a very hard time focusing both images on the exact same location. My intention was to focus on the hanging fish's left eye. However, since the focus sensor on the D300 is much bigger (relatively), it actually focused between the blue part just below the eye and the table top. The D700 was able to focus between the white and black parts of the eye. With the depth of field about 1 cm deep, this makes a difference when you look at the images at 100%. Anything faster than f/2.8 in the normal and above focal range appears to very rarely be necessary on the D700. Very easy to make mistakes.... In any case, the 85/1.4D at f/2 seems to be (as it should, being a prime) sharper than the VR 70-200/2.8 at f/3.2. The noise advantage, however, goes to the D700 due to the two stop help from the VR.
D300, 24-70/2.8G, 56mm, f/2.8, 1/30 sec, ISO 2500
D700, 85/1.4D, f/4.5, 1/30 sec, ISO 6400
The 24-70/2.8G is also a great lens. This time the 85/1.4D is on the D700. The 85/1.4 shows just a tad more contrast, but otherwise the images have near identical noise and Bokeh.
Nikon D300, Nikkor 85/1.4D, f/2, 1/125 sec, ISO 560
Nikon D700, Nikkor VR 70-200/2.8G, 130mm, f/3.2, 1/30 sec, ISO 450
Among the two images above, the D700 + 70-200 are sharper, with more contrast, and significantly less noise.
D300, 24-70/2.8G, 32mm, f/2.8, 1/40 sec, ISO 2500
D700, 50/1.4G, f/4.5, 1/40 sec, ISO 6400
Comparing the above two images, the D700 + 50/1.4G is sharper in the center, but otherwise nearly the same in every other aspect.
D300, 14-24/2.8G, 23mm, f/2.8, 1/50 sec, ISO 2500
D700, 35/2D, f/4.5, 1/50 sec, ISO 6400
Comparing the above two images, the D700 + 35/2D are just a bit sharper but otherwise the images are very similar.
D300, 35/2D, f/2.8, 1/40 sec, ISO 2500
D700, 24-70/2.8G, 52mm, f/4.5, 1/30 sec, ISO 6400
Between the above two images, the D700 + 24-70/2.8G is a bit sharper and more contrasty with similar noise levels.
