Beginning photographers often wonder what the best lens or focal length is for shooting head shots and portraits for actors, weddings, etc..
If you use a wide-angle lens like a 24mm, 35mm,50mm or even 70mm you have to move very close to your subject to get a good head size, and moving close expands perspective, elongating the subject’s features. If you use a longer lens you have to move back to get a good head size. Moving back compresses perspective, flattening the subject’s features. So using a longer lens like a 135mm, 200mm or even 300mm will give you the best results most of the time.
So what’s the optimum portrait lens?
It depends on how much of a person you want to show.
If you want the whole person standing, I would suggest a 50-70mm lens.
If you are photographing half the body (waist up) I would suggest a 70-135mm lens.
If you want just head and shoulders, I would suggest 135mm to a 300mm lens.
Here are some examples of different focal lengths.