Lens Distortion

UPDATE: read the post on Lens Compression here. 

By definition, lens distortion is a form of optical aberration when a lens creates curved lines where straight lines should be. It is the reason that some images look disproportioned compared to real life.

Wide-angled lenses typically create “barrel distortion” where the straight lines bend outward. This can make subjects in a portrait look wider or large-headed. Long lenses can create the opposite effect. Telephoto lenses typically produce “pincushion distortion” where the lines bend inward. This can have a slenderizing effect on portraits.

The three images below are of the same horse, taken with 3 different lenses:

The first image on the left was taken with a 35m prime lens. Because of the barrel distortion, the horse’s face almost looks cartoonish. The face is wide, pudgy, and significantly larger than the rest of the body.

The image in the middle was taken with an 85m prime lens. The lens distortion is less noticeable, but the mare’s head is still disproportionately larger than her body compared to what it looks like in real life.

The third image on the right was taken with a 135m prime lens. The head is in better proportion to the body and looks more lifelike.

When the horse is facing a camera like this, some of the distortion is also caused by perspective distortion because of the relative scale of what is distant versus nearby to the camera. Perspective distortion is caused by the angle of the image. Short lenses can cause objects close to the camera to appear abnormally large, while long lenses compress the distances which makes it more difficult to discern relative distance.

Because of lens distortion and versatility, the 70-200m lens is by far the most popular lens among equine photographers. Many photographers claim that 200m is the optimal length to photograph a horse to minimize distortion. Any less than 200m can make the horse’s head look too large, and any more than 200m can make the horse’s head look too small. This doesn’t mean that a horse can only be photographed at 200m, but it is good to be aware of the effects your lens choice can make on your images. For example, if you choose a lens with a shorter focal length, you can minimize the distortion by having the horse face sideways.

Curious to see what is in my camera bag? (I don’t even own a 70-200!)

Check it out

New to photographing horses? I have a course for you!

UPDATE: read the post on Lens Compression here.