The Canon EOS Rebel T3i / 600D and Nikon D5100 are two of the most popular DSLRs in the upper-entry-level category. Both deliver a step-up over the cheapest budget models, sporting a number of key improvements without breaking the bank or suffering from the size, weight and complexity of a mid-range or semi-pro body. No wonder each camera became a best-seller soon after launch.

The big question then is which one is best-suited to you personally? On the surface they seem to share a lot in common, with high resolution still images, fully-articulated screens and Full HD video with external microphone inputs. They’re also roughly the same size and weight, not to mention price when bought in a kit with their respective 18-55mm kit lenses. So unless you already have an existing collection of lenses or brand loyalty to one company over the other, it can be hard to choose between them.

But scratch below the surface and a number of important differences become apparent. Aside from the most obvious 2 Megapixel difference in resolution, there are variations in their screens, viewfinders, autofocusing, continuous shooting, movie capture, special effects, controls and user interfaces. Indeed more than enough to sway the decision one way or the other, depending on your requirements.

So to help you make the right choice, I’ve made a 20 minute video detailing ten of the most important differences between the two models and demonstrating them in practice. This video is designed to complement my existing reviews of both cameras, so for more information on each, please check out my Canon EOS Rebel T3i / 600D review and my Nikon D5100 review. Now scroll down for the video, presented here in High Definition and two parts.

The videos above were filmed around the Queenstown area in New Zealand’s South Island by Stefan Haworth using a Canon EOS 5D Mark II. Most segments were filmed with the EF 50mm f1.2L lens, while a handful used the EF 24-105mm f4L. The Shotover Jet Boat sequences were actually filmed with the cameras on test: the Canon EOS 600D / T3i was filmed by the Nikon D5100 and vice versa.

In all cases, audio was captured by a Rode VideoMic Pro, an excellent little shotgun microphone which every DSLR videographer should have in their bag. The videos were edited using Adobe Premiere Pro CS5.5, which I’ve found unparalleled for handling HD DSLR footage.

Thanks to the following for their help and filming locations:

Stefan Haworth for his videography – see his Tapped NZ blog for inspired photography.

Shotover Jet for the best thrill-ride which doesn’t involve flinging yourself off anything.

Dorothy Browns’ cinema, Arrowtown, for the movie mode location.

Lakes District Museum, Arrowtown, for the schoolroom location.

Skyline Gondola for the best elevated view in town.

Quiksilver for the in-store location and some rather nice hats. I wonder if they’d sponsor me?

And finally Vudu Cafe for the best coffee in Queenstown. That’s one of their cups you’ll see in most of my video samples and I’ve become hooked.

So if you’ve found this video useful and fancy treating me to a cup (or even a snack to go with it), please click the link opposite or below – cheers!