How to Choose a Lens
Compact digital cameras come with fixed zooms; we can't exchange them. Generally, it is a mid-range lens, for example a 18-55mm lens (which is equivalent to 28-90mm in film cameras, approximately), or a 18-105mm lens (which is equivalent to 28-170mm in film cameras, approximately). This means that with just 1 lens, we have a wide angle, normal and short telephoto lenses. In this case, we can choose the camera depending on the focal length of the lens it has.
In the case of SRL cameras (reflex which use film) or DSRL cameras (digital reflex cameras), we are able to choose what lens to buy depending on the picture we want to take. I recommend buying a mid-range zoom, such as 18-55mm, 18-105mm or even a 18-135mm for starters. Either one of these lenses will allow you to take different pictures and cover the majority of pictures you will shoot.
A second lens could be a long telephoto; a 18-200mm DX (or a 28-300mm for SRL cameras). This will allow you to take pictures from farther away.
If you like shooting portraits, I recommend you buy a fixed 80mm, 100mm or 105mm lens. They are really the best lenses for this type of picture. You will be amazed with the results you can achieve with them.
As we will see in later lessons, one important aspect we need to take into consideration about lenses is the open diaphragm it has available. If you can afford it, I recommend you buy lenses with a maximum diaphragm opening of at least f/2.8. These lenses are quite expensive, but they are worth it.
There are some DX lenses which have an image stabilizing system. This allows you to take pictures using a slower shutter speed without getting "moved" results. These lenses are also more expensive, but they are incredible whenever we take pictures in low light situations.
