July 24 2011
Photographers are no different from any other group of people, creating their own shorthand language to describe common objects or practices. Terms for lenses sometimes are obvious, others are cryptic, and can obscure the type of lens and its common uses in photography.
These are lenses with a wide view, and they capture more of the scene than the normal angle of view of the human eye. Lenses with a focal length of 35mm, or shorter, on a full frame DSLR are referred to as wide angle lenses. The wide view also translates into depth, making things seem further away and delivering an apparent greater area in focus, or depth of field.
The wide angle of view makes these lenses ideal for landscapes for capturing spreading vistas. This greater depth means more care has to be taken with composing the foreground and background.
For people shots wide angle lens help include everyone in the shot, especially in cramped places. One characteristic of the wide angle view is that everything looks smaller than the normal view. This enables photographers to work closer to the subject, an advantage where the distance between the subject and the photographer is limited.
This used to be a lens with a 50 mm focal length on a 35 mm film SLR camera. In the days before zoom lenses a 50 mm prime lens was also the kit lens, or the lens that came as standard with an SLR camera. So there are two meanings, the normal or standard lens, and a lens that offers the same angle of view as normal human vision.
The 50 mm focal length is the usual focal length of a standard lens, while with some photographers feeling a 43 mm lens gives a more natural view on a 35 mm SLR.
With the advent of zoom lenses the difference in focal length preferences are not as important, as the normal kit lens is 18-55 mm and this covers the standard focal lengths, as well as a useful wide angle range.
The name is a combination of tele, suggesting something traveling over a distance, the reflected light, and photo. This is a lens for photographing distant objects. Telephoto lenses produce magnified images, that look larger than normal size when photographing objects closer to the camera. Typically the focal length for a telephoto lens on a 35 mm SLR is from 70 mm and longer. Those from 500 mm focal length and up are sometimes called super telephoto to highlight their long focal length.
Lenses with longer focal lengths have a narrower angle of view making telephoto lenses good for isolating objects or part of objects. This is one of the reasons they are preferred as portrait lens, it is possible to get large close up image of the subject while maintaining a comfortable distance from the subject.
Telephoto lenses, long focal length ones in particular, are the workhorse of sports and wildlife photographers as sometimes it is difficult or dangerous to get close to the subjects.
This is not a specific type of lens, rather it refers to the lens that comes with a DSLR camera body as part of the deal. It is possible to buy the camera without a lens, and this is how most high end DSLRs are sold. Retailers sometimes make up their own kits of DSLR body and lenses, so there can be a variety of kit lenses for the same DSLR.
Photographers buying entry level DSLRs probably do not have a collection of lenses to suit their new camera. So they need a general purpose lens to get started taking photographs. To keep the price of the combined package low, this lens is often from the inexpensive end of the manufacturer’s lens range.
These are lenses with a large maximum opening, or aperture, letting in more light. Typically the apertures range from f2.8 and lower. Lower f numbers means larger apertures and more light coming in through the lens.
What is considered a fast lens varies with the focal length of the lens. Zoom, Wide angle, Telephoto and Macro lenses with f2.8 are usually considered fast, but a fast 50 mm prime needs to be in the f1 to 1.4 range.
Fast lenses are an advantage even for photographers using smaller apertures, or larger f numbers. All composing, metering, and focusing on modern SLR and DSLR cameras and lenses is done with the lens at maximum aperture. When the shutter is released the lens aperture changes to the setting for that image.
More light coming in through the lens gives photographers a brighter view of the scene and helps autofocus systems work better .
Why are they fast? Originally photographic films were very insensitive to light and long exposures were the norm. Lenses with a wider aperture allowed shorter, or faster, times for exposure.
This is a lens with variable focal length. The range of focal length is indicted in the name of the lens. The example photos were taken with a Sigma 18-125 mm zoom lens. So it goes from a wide angle at 18 mm focal length to telephoto at 125 mm focal length. One characteristic of many zooms is that as the focal length changes the maximum aperture changes.
For a true zoom lens the focus should not change as the photographer zooms, or changes the working focal length of the lens.
This is a lens with only one, or a fixed, focal length. Prime lenses have only one focal length and this allows designers to optimise their performance for one focal length. Prime lenses usually give slightly better image quality and are faster than a zoom lens at that focal length.
These unusual lenses use a combination of lenses and curved mirrors to achieve a long focal length in a compact lens. One of the drawbacks is that they have a fixed aperture, and the bokeh, or out of focus shapes, are unusual.
With f8 as a typical maximum aperture they are a bit slow compared to current telephoto lenses where a maximum aperture of f4 is common.
The solid object in the centre of the lens does not show in the photos taken using this lens.
A true macro lens reproduces small objects at their true size on the digital sensor or the film. This term is often wrongly applied to some zooms lens that can focus on objects close to the lens.
This is a specialist type of lens primarily used for architecture to solve the problem of tall buildings converging at the top of a photo. This happens when photographers angle their cameras upwards to include the top of buildings in their photos.
A shift lens allows photographers to hold the camera body vertical and move the lens to include the top of the building.
Adorama have a wide range of lenses for DSLR cameras.