Twenty-one megapixels. Think about it. Once the exclusive domain of those Tiffany-priced medium format digital backs, that same kind of high-end resolution is now possible with a D-SLR, albeit an expensive one.

I have to tell you that I have in my hands right now what I consider is the finest camera I've ever had the pleasure to use in more than 40 years of taking photographs, the Canon EOS-1Ds Mark III.

Canon's EOS-1Ds Mark III is the most sophisticated professional camera yet to emerge from the company's stable. Replacing the EOS-1Ds Mark II, which was released towards the end of 2004, it is the fourth in the line that began in 2002 with the EOS-1Ds and includes the EOS 5D.

2. Autofocus speed and accuracy including servo tracking are significantly improved in the Mark III camera. If you shoot action, the Mark III will give you more keepers than the Mark II. 3. Speed of image processing and file writing are blazingly fast with the Mark III.

I have owned the 1Ds, 1DsM2, and have a XT that I use as a backup. When I found out that Canon was going to release a DsM3, I sold my M2 on eBay. In the interim, Nikon of course released an awesome camera, the D3. I looked long and hard at both cameras.

Build; improved ergonomics; ability to configure settings to personal needs; great viewfinder; live view; good 3" LCD - great compared to anything previous; amazing resolution at 21.1 megapixels; fast fps ability at such high resolution

cost; could use AF in live view

Like other professional DSLRs, notably previous EOS 1Ds models and Nikon's D2x/D3, the EOS 1Ds Mk III is much taller than the average digital SLR. A big, fat battery housing sits in the base of the body, and this also allows space for an additional, vertical shutter release.

Canon's 1Ds series of cameras exists in a class of its own. With pixel counts well above anything else offered in a 35mm-format digital SLR, an attention to detail that addresses the needs of high-end professionals, and a price tag that's thousands of dollars more than the nearest competition, it...

Very low noise, high quality images; 21.1 megapixels; live view shooting; pro-level build-quality and performance

High price tag; heavy body; no AF in live view mode

The Canon EOS-1Ds Mark III is an imaging powerhouse. If you're looking for many megapixels in exchange for your well-earned pounds, this dSLR packs a whopping 21. With a large screen, live view and beefed up AF and exposure systems, this camera could revolutionise your photography

Very low noise; high quality images; Live view shooting; Pro-level build-quality and performance

High price tag; Heavy body; No AF in live view mode