Compared to...

Competition?

Deciding which camera to use for comparison to the EOS-1D Mark II is tough, its eight million pixels immediately put it way ahead in the resolution stakes to the nearest 'other brand' competition, Nikon's D2H. After this we have the 'prosumer' six megapixel EOS-10D and at the top end the eleven megapixel EOS-1Ds. Ignoring the performance difference (they really are cameras aimed at different markets) between the EOS-1D Mark II and the EOS-1Ds it happens to be the nearest professional competition. It seemed logical to see exactly how much you detail you would 'lose' going for the lower pixel count EOS-1D Mark II.

(Diagram is to scale for pixel count, not sensor size)

Outdoor scene comparison

The following shot is of Tower Bridge, London. Both shots were taken from the same tripod difference, to compensate for the different sensor sizes (and produce the same frame coverage) the lens zoom was increased for the EOS-1Ds shot. I was surprised at the difference in metering between the 1D Mark II and 1Ds, the Mark II required +0.7 EV compensation to match the 1Ds exposure (which was pretty much spot on).

Canon EOS-1D Mark II vs. Canon EOS-1Ds

Camera settings:

• Canon EOS-1D Mark II: Canon EF 24-70 mm (at 50 mm), Aperture Priority,
  ISO 100, JPEG Large/Fine, Auto WB, Shp+2, Self-Timer 2 secs, +0.7 EV compensation
   
• Canon EOS-1Ds: Canon EF 24-70 mm (at 60 mm), Aperture Priority,
  ISO 100, JPEG Large/Fine, Auto WB, Shp+2, Self-Timer 2 secs

Canon EOS-1D Mark II	Canon EOS-1Ds
ISO 100, 1/250 sec, F9	ISO 100, 1/250 sec, F9
2,877 KB JPEG (3504 x 2336)	4,104 KB JPEG (4064 x 2704)

Looking carefully down these 100% crops a few things are noticeable. First of all the EOS-1D Mark II images look cleaner, especially in shadow detail which looks particularly smooth and clean compared to the EOS-1Ds. Secondly that the EOS-1Ds can easily demonstrate its resolution advantage, the extra detail in the leaves of the distant tree and the rendering of tiles on the bridge roofs is outstanding. So it's fairly clear, the EOS-1Ds delivers the ultimate resolution, the EOS-1D Mark II the best compromise between resolution and performance (I'm sure there are plenty who would be willing to make that compromise).