The 21.9-megapixel Canon EOS-1Ds Mark III is Canon's flagship model, with superior weather sealing and durability. Reviews give this camera high marks for image quality, and tests show that although the Nikon D3S (*Est. $5,200 body only) can shoot faster, the Canon 1Ds Mark III has better autofocus in action shots. Its main advantage, however, is for landscape photography, where the high resolution makes for superior detail. The less expensive 21.1-megapixel Canon EOS 5D Mark II (*Est. $1,900 body only) isn't as durable but weighs less and can take high-definition videos.
We found the most objective reviews based on lab tests at PopPhoto.com, DxOMark.com and ProPhotoHome.com. Of these three, PopPhoto.com tests the most factors and evaluates overall image quality and usability as well. The review at DPReview.com is longer and more detailed, with useful illustrations of photographic tests. For direct comparisons with the Nikon D3, we turn to comparison reviews at Luminous-Landscape.com and Photo Business News and Forum, while the lengthy review at The-Digital-Picture.com includes detailed comparisons with other Canon models.
This detailed review, based on lab tests and hands-on usage, finds that the Canon EOS 1Ds Mark III provides "image quality and fine detail that rivals or exceeds that of many medium-format systems." The camera earns special praise for its autofocus, color accuracy and resolution.
Review: Camera Test: Canon EOS-1Ds Mark III, Michael J. McNamara , Dec. 2008
Lab tests of camera sensors rank the Canon EOS 1Ds Mark III below the Nikon D3 and D3X, primarily because the Canon 1Ds produces more noise at high ISO settings. However, the sensor on the Canon 1Ds Mark III gets slightly higher ratings than the Nikon D3 for color depth, and outranks other DSLR cameras.
Review: Canon EOS 1Ds Mark III, Editors of DxOMark.com
ProPhotoHome.com objectively tests the Canon EOS 1Ds Mark III by comparing action shots of a runner – concluding that the Canon outperforms the Nikon D3 in terms of autofocus.
Review: Canon 1D MKIII vs. Nikon D3 Sports Autofocus Showdown, Editors of and Contributors to ProPhotoHome.com, May 2008
This lengthy review covers all aspects of the Canon EOS 1Ds Mark III camera in detail, concluding with lists of pros and cons. Despite a few drawbacks, the review calls this camera "peerless" and, like the review at PopPhoto.com, positions the camera between pro digital SLR cameras and medium-format cameras.
Review: Canon EOS-1Ds Mark III Review, Simon Joinson, Aug. 2008
5. Luminous- Landscape.com
Comparing the Canon EOS-1Ds Mark III with the Nikon D3 and D300, landscape photographer Reichmann provides comparison photos of close-up details but doesn't recommend one camera over the other.
Review: Oh No! Not a Nikon/Canon Comparison! Yes. I'm Afraid So, Michael Reichmann, Dec. 2007
6. Photo Business Forum
This detailed hands-on comparison review favors the Canon EOS-1Ds Mark III over the Nikon D3 for large prints, but judges its higher resolution less important for most shots. For shooting in low light, the Nikon D3 has the edge.
Review: Nikon vs. Canon, John Harrington, Dec. 2007
7. The Digital Picture
This review compares the Canon EOS-1Ds Mark III with a host of other Canon digital SLR cameras, but not with Nikon models. The reviewer is mostly enthusiastic about the 1Ds Mark III, but his unit shipped with a dirty sensor that was hard to clean.
Review: Canon EOS 1Ds Mark III Digital SLR Camera Review, Editors of The-Digital-Picture.com