Focal length is by far one of the most important choices you can make when it comes to portraiture, as it makes a huge difference on how your subject is rendered. This helpful video will show you how five different common focal lengths render the same subject.
Coming to you from Jessica Whitaker, this excellent video will show you how five different focal lengths render portraits differently, including 24mm, 35mm, 50mm, 85mm, and 135mm. Traditionally, portrait photographers generally opt for a focal length around 85mm. This is because at wider focal lengths, perspective exaggerates the features in an unflattering way. On the other hand, as you get into longer focal lengths, compression takes over and begins to flatten the features. Photographers generally like a focal length around 85mm because it avoids creating unflattering renderings, but it preserves enough of a person's unique facial geometry to create an interesting image. That being said, you certainly do not have to stick to the most common choice; for example, a lot of photographers prefer a 135mm lens for their work or even a 200mm, though you will also start to run into difficulties with your working distance after a while. Check out the video above for the full rundown from Whitaker.