Some lens have variable focal lengths. Those with a set length are prime lenses.
Camera lens define many qualities of the final photo. The quality of the glass in a lens always improves the quality of the final product. Different lens also have different apertures. A higher quality lens can be opened wider to let in more light and improve the quality of the image. However, whatever the quality of the lens, its focal length is often the most challenging aspect for a photographer to choose.
Medium-Long Lenses: 70-135 mm
This length of lens is the standard for most portraits. It helps to slightly flatten the face of the subject and tends to have a smaller depth of field especially if a prime lens is used. This allows the photographer to isolate the subject from the background. A long lens may also have more smoothness to the out of focus areas which is popular for medium format portrait photography because the photographer can be a smaller distance from the subject.
Normal Lenses: 35-75 mm
These focal lengths are the best representation of the way the human eye sees the world. 50 mm is considered the standard. The image is not flattened or widened very much by this focal length. It is a good choice for medium format photography because of its "what you see is what you get" appeal.
Wide Lenses: 22-35 mm
Wide lenses are uncommon for portraiture because they have a tendency to flatten the subject out and make them look heavier. However, some photographers like the distorted view that a wide angle lens provides. This view can be very good at conveying certain mental and emotional states, and is more likely to be used for artistic portraits. Some photographers veer into extremely wide angle lenses, those below 22 mm, for the fish-eye or panoramic-style portraits.
Extreme Telephoto: 135-300+ mm
These are by far the least popular for medium format portraits, however they do have their uses. At this length, the lens tends to be slower because of the distance light is traveling. It also tends to lose detail. The subject will be very flattened and it can be a challenge to separate the subject from the background. The photographer must also contend with being very far away from the subject due to the magnification of the lens. In general, telephoto lenses are used for photographing things at great distances.
Tags: also have, focal length, focal lengths, from background, from subject
