Choosing the right lens is an important part of getting the results you want. The two most important things to consider are ‘Focal Length’, and ‘Depth of Field’.
Let’s start with focal length. Focal length refers to how much you can see through the lens. It’s important to note that the two most common lenses are zoom lenses and prime lenses. A zoom lens has the ability to zoom in or out through a range of different focal lengths. For example, my 17-40mm lens can shoot at both 17mm and 40mm and all points in-between. Whereas a prime (or fixed) lens has only one focal length and cannot zoom. If you want a closer or wider shot with a fixed lens, you have to physically move forward or backward. Let’s take a look at some of the different ranges:
As you can see, 18mm (and lower) have the widest focal lengths and are considered wide angle lenses. Wide angle lenses are great for landscapes and interiors because you can fit a lot into your shot. A 200mm lens would be considered a telephoto lens, and they’re great for zooming into shots that may be further away. To give you an idea of how a shot looks at different focal lengths, I took three shots, standing in the exact same place, with three different focal lengths.
Remember, I stayed standing in the same place when I snapped all three shots. I never backed up, or moved forward. Look how close the 50mm lens is compared to the 10mm lens. Pretty cool, huh?
Now it’s easy to see why 50mm lenses are so popular for shooting portraits. It’s a great lens for capturing closer shots with that beautiful blurry background. And speaking of beautiful blurry backgrounds, that brings us to the second part of choosing the right lens which is ‘Depth of Field’.
Depth of field refers to how much of the image is in focus, and this is accomplished through aperture. Different lenses come with different maximum aperture openings. You can read more about how it actually works here, but for now, the important thing to remember is simply this: The smaller aperture number (f/1.4) equals a more shallow depth of field which makes the blurry background.
So choosing the right lens depends greatly on how you want to final image to look. If your going for an up-close look with a blurry back ground, prime/fixed lenses with wide apertures (f/2.8 or lower) will do the trick, but if you’re shooting a bedroom or bathroom, you’re going to want a wide angle lens that will take in as much as possible without distorting. I shoot most of my interior shots with a 17-40mm lens, how about you?