What is cameras focal length

So even though they are very different numbers they produce the same result because of the size of the imaging surface. Camera manufacturers sometimes list these equivalents because some photographers are more familiar with 35mm cameras and they want to make it easier to understand. It also gives us a standard of reference for all the different format sizes.

They may also list the multiplier factor. For example, the APS-C multiplier is around 1. Does focusing affect the focal length? Above we mention that focal length is related to focus distance.

Focal length is the principal distance of a camera when it is focused at infinity. All lenses have a stated or specified focal length value or range of values for a zoom lens. This printed number is actually its nominal length or the principal distance when the lens is focused at infinity. As you focus on objects that are closer to the camera, the principal distance changes.

So for example, a 50mm lens focused on an object a few feet away might have a principal distance of 55mm lens at that time. Standard Lens FX format approx. Telephoto Lens FX format approx. Super Telephoto Lens FX format approx. More Like This More articles like this. Article Collections. Articles like this, right in your inbox. First Name required. Last Name required. Email required. Popular Topics. More from Nikon. The longer the focal length e. To view this content, JavaScript must be enabled, and you need the latest version of the Adobe Flash Player.

Lenses with a wide picture angle are referred to as wide-angle lenses, lenses with a small picture angle as telephoto lenses. A zoom lens with a focal length of 18—55 mm offers the widest picture angle at 18 mm and the smallest picture angle at 55 mm. If the only lens available is an 18—55 mm zoom lens but you want wider angles—say, for landscape shots—you should buy a lens that offers focal lengths shorter than 18 mm, for example, a 10—24 mm lens.

If, on the other hand, you want to photograph at greater distances, you should choose a lens that offers focal lengths longer than 55 mm, for example 55— mm. The shorter the focal length, the greater the extent of the scene captured by the lens. On the other hand, the longer the focal length, the smaller the extent captured by the lens.

These focal lengths can be found in the lineup of most manufacturers. Rectilinear wide angles project an image in which the straight lines remain straight. Fisheye lenses distort the scene into a spherical shape. Fisheyes are rather special tools. Wide-angle lenses are used by photojournalists for documenting situations. This is because they are wide enough to include a lot of the context, whilst still looking realistic.

The widest lenses commonly used in movie production also fall into this range of focal lengths. Their field of view is ideal for showing plenty of the environment. But thanks to the wide aspect ratio, subjects can be far enough away to not appear distorted. I like to use this range when shooting on the street or with friends in a closed setting. Examples would be at the dinner table or the pub. Standard lenses as called standard for a reason — these are the most common lenses, in both prime and zoom format.

It will provide excellent results. A prime lens will always provide better results than your kit zoom lens, as it is built with a single purpose. It does one job well. Kit zooms also fall into this category.

They usually cover a zoom range of mm on crop cameras or mm on full-frame and film cameras. Both of these zooms cover the entire standard range, as well as some wider angles.

This range is often where kit lenses stop. This is a good range for portraits as the perspective of the lens will make human faces look natural. Most short telephoto lenses separate the face from the background, without completely isolating it. A large proportion of dedicated macro lenses also falls into this category. This is because short telephotos are long enough to provide enough working distance. But they are short enough to not make huge macro lenses.

Their fairly natural perspective also plays a big role in this. Lenses in this range are often used for distant scenes such as buildings or mountains. But they can provide interesting perspectives in that field, too.

Lenses in this range are often used for sports and animal photography. Portraits are also a great genre to use them in. Shooting portraits with long lenses can provide exceptional subject separation and background compression. There are hard-to-imagine extremes in this range.