When you are shooting with a wide angle lens or a zoom lens, the amount that you are zoomed in or zoomed out is called the focal length. On a DSLR lens, you can see the focal length you are at when you look on your lens. For point and shoot cameras, the focal range of your lens is written on the front of the lens (my Canon PowerShot SD30 says 6.3-14.9mm). The “mm” numbers on the lens is your focal length range. For my point-and-shoot, when I am at 6.3mm the lens is at its widest focal length….and when it’s at 14.9mm it is at it’s farthest (most zoomed) focal length.
Why is it worth knowing a bit about this? Well, when you are taking a picture of someone you often want them to look as good as possible. You want the picture to look natural and be a good representation of that person. When you are taking a picture of someone at a wide focal length the resulting image ends up being distorted because of the way that the lens captures the image. When you are at a long focal length (for DSLR cameras 70mm or more) you get an image that is much less distorted and more an accurate representation of what that person looks like in real life.
Here is an example.
The left image was shot at 42mm and you can see the shape of Tyler’s head is a bit distorted/egg shaped. This is because the photo was taken at a relatively wide angle for taking pictures of people. Now look at the picture on the right that was shot at 115mm. His face and features look much more natural and are definitely closer to what you would see in real life if you were sitting across the table from Tyler.
I should mention that Tyler is participating in Movember….a month of growing a mustache to help raise awareness of men’s health issues, and in particular prostate cancer. You can go here to check out his Movember page, rate his “Mo”, and maybe even donate some money towards prostate cancer research?