Of course, these factors are highly dependent on the lens used, but let’s assume we’ve got a good one mounted on the camera.

The 1Ds has a very weak Anti-Aliasing (AA) filter, which makes the camera capable of producing razor sharp images without the need of significant sharpening in the post processing. I would go as far as to claim that the 1Ds produces overall very, very sharp and detailed images. It is probably the sharpest one I’ve experienced so far, the 5D included.

The 1D2 on the other hand has a fairly aggressive AA filter, which took me some time to get used to. I guess that in high-speed and complex sports scenes (which is the target usage for the 1D2), moiré is a bigger problem than a slight amount of softness. We’re talking about < 200 DPI printing. However, the 1D2 images are highly responsively to sharpening in the post processing, so for most shots this is not an issue at all. As my 1D2 is dead now, I cannot present any comparison shots with the 5D.

The 5D seems to be somewhere in the middle and I believe that the more aggressive noise cancellation algorithms introduces some softness. However, by all practical means, the sharpness is more than excellent.

There is a fair amount of buzz regarding image degradation with FF sensor bodies, like the 1Ds and the 5D, where primarily corner/edge sharpness falloff and vingetting. Yes – one can get insane when studying MTF graphs where primarily wide angle lenses show a shocking performance degradation towards the perimeter, but in almost all practical settings (at least for my own needs) – the attention is towards the the center of the image – not in the perimeter. The capability to be able to use longer focal length (= less distortion) with the larger FOV with the FF sensors very much compensates for these two drawbacks I think. Suddenly, the superb EF 35/1.4L can be used as a wide-angle – a lens that is pretty much “neither-nor” on a 1.6x crop body. Extreme zooms, like the optically inferior 12-24 range can be replaced with the much better 16-35 range, yet giving the same or even better reach.

For my personal requirements, I value the following practical performance factors the most:

The ability to create smooth yet distinct transitions between overexposed (or near overexposed) areas and dark objects, such as treetops, power lines, telephone poles, fine hair details etc. towards a bright sky or other high contrast transitions. I’ve lost a fair amount of otherwise excellent images by bad performance in this respect. A typical scene is a dark locomotive shot towards a bright sky, where the overhead catenary wire is entirely blown out together with the sky.

The overall ability to resolve fine details, such as hair, fine lines, telephone wires etc. without creating too sharp edges and/or halos. The typical scene here is tree branches or fine leaves towards a sky. Another common example is an outdoor portrait where fine hair details can get lost towards a bright background, even when correctly exposed.

The ability to make reasonable crops without finding that fine details, such as tree branches just end up in a messy kludge.

As some kind of bottom line and/or conclusion here is that both the 1Ds and the 5D are very good in this respect. The 1Ds wins in pure sharpness whereas the 5D strikes back when it comes to smooth transitions in high DR scenes. At high ISO settings, the 5D is clearly more distinct – no doubt about it.