A look at Canon's latest full-frame camera, compared with the Nikon D800 and Canon 5D MK II

The Canon 5D Mark III has just been announced, which replaced the 3 1/4 year old 5D MK II. In the Canon 5D Mark III, Canon has made some major improvements from the Canon 5D MK II, especially in the areas of auto-focus and high ISO performance – and is sure to appeal to professionals shooting  sports, weddings, and low-light action. It inherits many of the great features of the Canon 1DX, as they share the same Digic 5 image processor.

However, for people not locked into lenses, the newly announced 36MP Nikon D800 offers some very serious competition, especially for wildlife and underwater photographers.

Canon 5D MK III price and release date

The camera is expected to be available at the end of March, 2012 at a price of $3,499 for the body, or $4,299 with the 24-105mm f/4L zoom lens. The Nikon D800 body is a little less at $2,999 - and the 5D MK II can now be picked up for just $2,199.

Key improvements of the 5D MK III over the Canon 5D MK II

• # of Auto-focus points boosted from 9 to 61
• High ISO performance increased by up to 2 stops; the 5D MK III can be "boosted" to ISO 102,400
• Shooting speed increased from 4fps to 6fps
• Video limit increased to 30 minutes
• In-camera HDR mode added
• Adds 720p video at 60fps, for slow-motion video
• Adds a quiet shooting mode
• Dual card slots. Supports SD cards as well as CF
• New, higher price!

1. Min aperture for auto-focus is important when using teleconverters
2. This camera was $2,699 in early 2009
3. Weight with battery & card
4. It remains to be seen how useful the auto-focus is during video, it was not great on the D7000
5. The ISO can be "boosted" by 2 more stops on all of these camera model

Comparing the 5D MK III and the Nikon D800

The Canon 5D MK III and the Nikon D800 are quite similar in size, weight, sensor size, LCD, viewfinder, storage media, video resolution, battery life, and weather sealing. Both can do in-camera HDR (high-dynamic range photos).

The main differences are listed in the table above. The Canon 5D Mark III has the advantage of being able to shoot at very high ISOs, and a faster shooting speed, due to its lower megapixel count and fast image processor.

The Nikon D800 has the advantage in other areas including megapixel count, auto-focus ability with teleconverters (for example - you can use autofocus with a F4 lens + 2x teleconverter with the D800), having an internal flash, and sync speed. The internal flash and sync speed may be useful for some underwater photographers.

I expect to see Canon 5D MK III underwater housings from Aquatica, Hugyfot, Ikelite, Nauticam, Sea & Sea, Seacam & Subal - and I predict that both the Canon 5D MK III and the Nikon D800 will be very popular with both professional and serious amateur underwater photographers.

Further Reading

• Comparing the Nikon D800 with the Nikon D700 and Nikon D4

• Comparing the Nikon D4 with the Nikon D3s and Canon 1DX

• Canon 5D Mark III Review

• Best Underwater Settings for Canon 5D Mark III