The $1200 price tag of the 70D is for the "body only". Since these are removable lens cameras, some people are upgrading from previous bodies and they already lenses -or- they don't want one of the lenses offered as a "kit" and prefer to find something else.
The 70D _with_ an 18-135mm zoom is a bit over $1500. That's Canon's new "STM" lens which is much faster focusing than the previous 18-135 and the optical quality is also improved... but not as fast and snappy as Canon's "USM" lenses. The difference between the "STM" and "USM" lens is the type of focusing motor in the lens. The "USM" lenses are fairly quiet and quite snappy. The "STM" lenses are fast, but not as fast as the USM... but they are exceptionally quiet -- so quiet that when filming video the sound of the motor cannot be heard by the built-in microphone on the camera.
The T5i and T3i are also going to do great job at action photography / sports, but the 70D has more cross-type auto-focus points and a faster continuous shooting speed -- it also has paritularly good continuous focus when shooting video. The T5i has that but it's not as good as the 70D. The T3i does not continuously focus in video mode.
The cameras are just tools... the tool has to be adequate for the task, but to really exploit the tool you have to learn to use it. Some proper camera stores (not big box stores that happen to sell cameras) offer classes to customers who buy cameras from them. It's one of the benefits of using a real camera store. There are also some very good books highly recommended for beginners.
All DSLRs have a fully automatic mode. Point it and take a picture... just like a point & shoot. But that's sort of wasting the capabilities of a camera that can do so much more.
The camera also has some scene-based modes... these are found on all "Rebel" bodies as well as on the mid-range bodies such as the 70D. These scene based modes are not found on the high-end bodies because the scene mode is really just a mode that tells the camera "I'm about to shoot some action shots" and the camera understands what it needs to do to pull those shots off. And that primarily means tells the camera to do THREE major things:
1) Use fast shutter speeds... by "fast" we mean speeds like 1/500th or faster... but whatever the lighting, optimize the camera to try to use fast speeds.
2) Change the focus mode to a continuous mode -- expecting the subject to change distances. (In the default mode, the camera only focuses until it's able to achieve focus on a subject and then the focusing system stops and waits for you to shoot... the default mode of the focus system does not expect subjects to keep moving or focus distances to change.)
3) It puts the shutter into high-speed continuous shooting mode (meaning... if you press and just keep holding down the shutter button... the camera will just keep shooting as fast as it can. In the default mode the camera would just take one shot only and wait for you to release the shutter button.)
Experienced photographers know that they need to change these settings to shoot action -- having the scene-based mode is really just redundant. But the scene modes are convenient for photographers who have not learned about all these various controls.
That means you could just put the camera into the "action" mode and go have fun with it ... not worrying too much about how it knows what to do.
You can improve your photography by learning more about the settings that control the exposure and take the camera out of the automatic modes and start using the semi-auto and manual modes -- these modes offer you more control over the outcome.
Most consumer lenses are priced in the $200 to $500 (or maybe $600) range. There are some higher end lenses that run $1000 and up. Canon probably makes 75 lenses or more that work with that camera.
For "daytime" action photography, the kit lens that comes with the camera will do fine, but you might want a lens with a telephoto zoom for field sports. The lenses in the $500-600 range tend to have Canon's "USM" focusing motors which are fairly quick at focusing.
There are lenses that are good in low light and don't _necessarily_ cost a lot of money. Canon makes a 50mm f/1.8 lens that costs around $125 (give or take) which is great for low light BUT it has a slow focusing motor -- not fast enough to keep up with rapidly changing focus situations like action shots. Canon makes a much faster 50mm lens but it's closer to $400.
Where it does get painful is the lenses which are great telephoto zooms AND are able to collect a LOT of light. Those are not inexpensive lenses (e.g. $2000 and up). Again... for "daytime" sports, those lenses aren't needed. These expensive lenses are good in situations where the available light is rather poor, but you still need a fast shutter speed (e.g. night-time sports games or indoor sports such as basketball played in gymnasium where the lights are not particularly bright by photography standards.)
Tim Campbell
5D III, 5D IV, 60Da
