Yes, the EF-S 18-55 IS is a good starter lens for very little money. Bought in kit with one of the cameras, it's usually a particularly low cost option. If you want a little better and more versatile lens, the Canon EF-S 18-135 is often offered in kit, too... but costs a bit more. If you have more to spend and want a versatile lens, the Canon EF-S 15-85 IS is very popular, a little wider. Also fairly expensive, a larger aperture option is the Canon EF-S 17-55 IS. Morro Bay harbor
Just to clarify a little, folks are correct telling you that the 18-55 can give you deep depth of field ( a lot of the image from near to far acceptibly sharp and in focus). To accomplish that, you use a smaller aperture in the lens, such as f5.6 or smaller. I know it's a little confusing, but the higher number of the aperture, the smaller it gets (it's actually a ratio is why: focal length or f over the aperture size). Thus, the larger apertures (that give less depth of field) are f1.4, f2, f2.8.... The middle size apertures (where a lot of lenses are their best optically) are f4, f5.6, f8... and the smallest apertures (that give more depth of field) are f11, f16, etc.
All lenses you will be considering can be stopped down to smaller apertures to render greater depth of field. At the other extreme, some lenses have larger maximum apertures than others and allow shallower depth of field.
The 18-55 is a zoom with a variable aperture range: f3.5 to f5.6. That means that at 18mm setting, it's largest possible aperture is f3.5, but it can be stopped down to smaller apertures than that. At the 55mm setting, it's largest aperture is f5.6 and it can be stopped down to smaller apertures from there, if you wish. Many zooms are made with variable apertures such as this, because it is less expensive and allows them to be smaller and lighter weight. There are constant aperture zooms that have f2.8 or f4 throughout their zoom range, at all focal lengths, but they are much more expensive, a lot bigger and a lot heavier.
Some responses have mentioned the Canon EF 50/1.8, a relatively inexpensive prime lens (ie., not a zoom) with a larger aperture that can be useful to make depth of field even shallower, such as to blur down a distracting background a lot when shooting a portrait. Compare with the 18-55 zoom, which at similar 55mm focal length can only achieve f5.6... The 50/1.8 is able to open up more than three additional f-stops, so can render much shallower depth of field.
Focal length of the lens determines the lens angle of view. 18mm on T3i is "moderately wide angle", about 30mm is "standard", 55mm is "short telephoto" and 135mm is "moderate telephoto". For some types of photography you mention - scenery - people often want a standard to wide to very wide or even ultra wide lens: 30 to 18mm, 15 to 12mm, even 11mm to 8mm. For portraits, often people use short telephoto: 50 to 85 or 90mm. For sports and action photography, they often use stronger telephotos, 100mm on up to 500mm and even longer. These are just a few examples.
Focal length relates to depth of field, too. The wider angle (shorter focal lengths) are easier to render deep depth of field, shots that are sharp from near to far. A 20mm lens, for example:
EF 20mm f2.8 lens at f5.6, with B+W Kaesemann C-Pol filter. EOS 50D at ISO 200, 1/400 shutter speed. Handheld, available light (no flash).
Longer focal lengths more easily render shallow depth of field, heavily blurred backgrounds. A 300mm lens:Cloverleaf barrels April 20011 CSHA Region 3 gymkhana, Dunnigan, Calif.
EF 300mm f4 IS lens at f6.3. EOS 7D at ISO 400, 1/1000 shutter speed. Handheld, avail. light.
Another factor with depth of field is your distance from the subject... Up close, the same focal length and aperture will make for even shallower depth of field. Here's another shot with the same 300mm lens, only a lot closer:Young ground squirrel with eucalyptus leaf
EF 300mm f4 IS lens at f5.6. EOS 7D at ISO 100, 1/400 shutter speed. Handheld, available light.
I suggest anyone new to photograqhy and seriously consider getting the book "Understanding Exposure" by Bryan Peterson
. It's an easy read and full of great info about a lot more than just making good exposures... it also goes into choosing lenses and apertures for various subjects.
Canon has a lot of info about lenses on their website... http://www.usa.canon.com …ts/cameras/ef_lens_lineup
For a lot more detail, specific to Canon, you might want to download Canon Lens Work III
, or try to find a copy of that hardbound book somewhere.
Many of the camera-specific guidebooks
also contain a chapter discussing lenses and their uses in good detail. These books are good to have, anyway. They expand upon the info in the manual that comes with the camera.
In a nutshell...
On a budget, the 18-55 IS kit lens is a good "starter" lens to learn with.
Or, if you have a bit more to spend and want a little more telephoto reach, the 18-135 IS is sometimes offered as an alternative kit lens at a little higher price.
Or, if you want a bit wider lens and have more to spend, the 15-85 IS might be a good, versatile yet reasonably compact choice. You won't likely find it in kit, so expect to buy camera and lens separately and not get any sort of kit discount.
Or, if you want a faster lens, one with a bigger aperture, and have the budget for it, the 17-55/2.8 IS is a good choice. But, again, you won't likely find it in kit and should expect to buy camera and lens separately, probably won't get any sort of kit discount.
Whatever lens you get, I suggest buying the matching accessory lens hood for it and using it. The most obvious reason, the hood helps protect the lens against oblique light that can cause image problems such as veiling flare, loss of contrast, reduced color saturation. Wide angle lenses are harder to effectively shade than telephoto lenses, and zooms are harder to shade well over all their focal lengths, than a prime lens is with it's single focal length. But a matched hood designed specifically for the lens will do as good a job as possible. And a lens hood also protects against physical bumps while shooting, even provides some protection while stored in reversed position on the lens. It's just a good thing to do, to get in the habit of using the lens hood. In some cases Canon's are expensive... There are cheaper third party hoods available on eBay or at many of the major online retailers. Just search by the model number of the Canon hood, to see the alternatives.
I don't recommend a "protection" filter. Cheap ones often do a lot of harm to images and can even mess with auto focus. Good ones do minimal harm to images in all but the most extreme situations and generally don't effect AF, but get pretty pricey. Generally speaking, they don't provide much real world protection, either... after all, it's just a thin piece of glass!