Canon's Rebel T2i is an incredible camera—everything a first DSLR should be. It takes fantastic photos (and, crucially, video) for the price, it's easy to use, and perhaps most importantly, it's a camera you can grow with.
But there's no shame in using it if you really know what you're doing, either.
That's in part because it's a semi-pro camera, dressed down. The $900 T2i is essentially Canon's mid-range $1900 7D, one of the best DSLRs for the money, shoved into a simpler, smaller body. Namely, it uses an 18-megapixel APS-C image sensor that's not too different from the 7D's; the same 1080p/full manual video capabilities; and the same IFCL 63-layer dual-zone metering system, adjusted for the T2i's different autofocus setup.
And for anyone just getting into DSLR photography, the power to package ratio is phenomenal. That said, it still feels like an entry-level DSLR, for better and worse.
The plastic body is more like a nice (but large) point-and-shoot than a tank-like, pro camera. Everything about the design feels nimble—it's relatively compact and light in your hands with just enough rubber and ergonomics in the grip to wield the camera effectively. Firing the shutter releases a high pitch, bottle-rocket style shot, rather than the baritone cannon boom of a big DSLR.
Completely new to the Rebel line is the T2i's 1.2 million-dot, 3-inch display, reshaped for the first time into a 3:2 aspect ratio (so your pictures actually fit on there without getting cropped). It's insanely great, with enough brightness to use in daylight along with a near-180 degree viewing angle, which means shooting video using Live View (the setting where you see what you're shooting on the screen in real time) that much nicer. (And speaking of video, it supports the newer SDXC memory card format—which promise storage capacities of up to 2TB—meaning you'll be able to shoot a lot of it on a single card, if you can afford the card, anyway.)
The straightforward mode dial system will look familiar if you've ever picked up a Canon point-and-shoot, and along with a shortcut button, you can quickly fiddle with any parameter on the screen (ISO, shutter speed, etc). That said, sometimes I missed the added control of the secondary jog wheel that graces the back of Canon's more expensive DSLRs.
For true beginners, it carries over shooting modes from Canon's smaller, casual cameras, like Night Portrait and Sports. Creative Auto is notable in this regard, a mode that simply asks you how blurry you'd like the background to create those ever-hot bokeh effects (rather than making you fiddle with the aperture on your own).
All in all, the T2i appears to be a nice entry-level camera with the heart of something more. Pros may nasally gripe about the build and access to some controls, but for you, Mr. Amateur Photographer? It'll feel highly accessible and plenty-good in your hands.
With the T2i, Canon has both increased the image resolution—to a full 18MP—while bumping normal ISO sensitivity up to 6400. This is a somewhat odd move in the industry at the moment, as increasing megapixels can thwart low light performance (and everyone is all about low light right now). But the T2i juggles both improvements with grace.
Remember, the T2i's sensor is basically the same as the 7D—its sensor uses the now popular gapless microlens architecture to capture as much light as possible—meaning the T2i's results stack up pretty nicely to its $1900 forebear.
DxOMarks' image sensor benchmarks bear this out, with the T2i scoring nearly identically to the 7D, suffering only slightly in low-light, high ISO conditions.
(I've also thrown in the Nikon D90 for good measure.)
In other words, the camera performs pretty damned impressively in low light conditions:
ISO 800, f7.1, 1/200
ISO6400, f5.6, 1/30
Here's a comparison gallery to check out. If you want to see even more, full resolution shots, there's a Flickr link if you scroll down a bit.
Bottom line, the T2i does well with low light until you push the ISO speed beyond 1600 (where the image can get so grainy it's not worth taking). That said, an entry-level DSLR producing truly acceptable images at ISO 1600, and occasionally tolerable ones at ISO 3200 (heck, even the 6400 ISO street scene above looks decent), is kind of remarkable—it's trickle-down tech of the most democratic order, and it will provide a really nice amount of flexibility for beginning shooters, letting you do more with natural light before possibly getting into the more advanced lighting techniques like you might see on the Strobist.
DSLR Video and Existential Angst
Video is in fact, perhaps most axiomatic of the T2i's ability to scale with a first-time DSLR owner as their skill grows. Unlike its predecessor, the T1i—or even the professional 5D Mark II before a firmware update—it's not at all artificially limited. It shoots h.264 video in 1080p resolution at 24 or 30 frames or second, or 720p at 60fps. It's mostly excellent, and I'd venture, to the average eye, nigh indistinguishable from any video the 7D produces.
With the video I've shot, I stuck to producing casual lifestyle content—puppies, parties, concerts—using simply the kit lens. Most of the cuts I provide here lean toward low light, so you can get a feel for the way it performs under strain.
Though you can obviously tell by looking at the video, noise starts to become an issue around ISO 1600, and deeply problematic by ISO 6400 (unless you're going for that look), but it's to be expected.
(FYI: For 24fps video, the shutter speed stayed on 1/50—any exposure adjustments were made via aperture or ISO. For video at 60fps, the shutter speed was kept at 1/60.)
I tend to dislike the 60fps video because it feels a lot more like digital video, so it's unfortunate that you're stuck at that framerate when you want to shoot at 720p to save space or processing speed or both. (And converting 60fps to 24fps in post to recreate the look is a pain.)
One of these clips is shot by the T2i. The other is shot by the vastly more expensive 1D Mark IV, using the same settings. Can you tell which is which?
You can imagine a natural arc—used to shoot the things a Flip isn't good enough more, maybe with the kit lens or just a cheap prime. And then someone's feeling creative, and a Zacuto DSLR viewfinder sounds like a good idea, the pains of DSLR video still very much apply.
Wobbly jello motion if you pan too fast? Yep. (Though it's much better than the very earliest DSLR video.) Maximum clip limits? Yep, still 12 minutes, because of file format restrictions. Bring your own stereo mic? Yep. Awkward controls? Yes, though the T2i's are the most intuitive around, precisely because it's designed to be a beginner's camera: There's a dedicated movie mode on the dial, and the record button has been placed far more gracefully next to it, for easy, but not accidental, thumb access.
Nonetheless, the T2i is a true hybrid still/video camera. That's something deeply powerful.
The T2i is the ideal first DSLR. The simple controls shouldn't intimidate you for long, plus it can hold your hand a decent bit of the way, thanks to clever innovations like the Creative Auto Mode.
But the T2i may also be the ideal last DSLR, as it offers most of the performance of a camera that's twice the price, albeit in a slightly more pedestrian body. If I were a filmmaker choosing between a single 7D or dual T2is for multi-angle shoots? The choice would be pretty obvious. And if I were a random guy just looking for my first DSLR to dabble in photography and video? The choice would be pretty obvious there, too.
An awesome camera for the price
Easiest video controls of a Canon DSLR with video yet
Still bound by the limits of an entry-level DSLR, like slower shooting speed
All of the standard DSLR video problems still abound