Wide Angle Lenses

From Peter Marshall

Using Wide Angle Lenses

What are wide angle lenses?

Wide-angle lenses are those that give a wider angle of view than standard lenses. To do this they need to have a shorter focal length.

Using Wide Angles

Wide-angles are the most misunderstood of lenses, at least so far as beginners in photography are concerned. They tend to see a wide-angle as being used 'to get everything in'. There are a few cases where they do enable you, for example, to photograph room interiors which could not be done with a standard lens, but their main use is to allow you to get closer to the subject.



Working with a wide-angle you tend to engage more with whatever you are photographing, getting closer to it in every way. Wide-angles are 'hot', involving you more closely with whatever you are photographing. Technically, wide-angles are easier to use, giving you greater depth of field and cutting down the effect of camera shake, but compositionally their wider viewpoint tends to make images more complex. zSB(3,3);if(!z336){var zIsb=gEI("adsb");if(zIsb){zIsb.style.display="inli ne";zIsb.style.height="0px";zIsb.style.width="0px" ;}var zIss=gEI("adss");if(zIss){zIss.style.display="inli ne";zIss.style.height="0px";zIss.style.width="0px" ;}}
For 35mm cameras, the format diagonal is 43mm and typical standard lenses have focal lengths of 40-55mm. Wide-angle lenses are generally 35mm focal length and less.
35mm

35mm is only a slightly wide-angle compared to the format diagonal, and only a little more wider if compared with the typical standard lens of 50mm focal length. Many photographers have used a 35mm lens as their normal lens, either on a rangefinder or an a fixed lens compact camera.

35mm is a fine lens for candid work with a rangefinder or compact camera. It's relatively wide angle of view means that precise framing is less essential when working close to the subject. It also gives and increased depth of field compared to the standard lens.

Fast 35mm lenses, such as the 35mm f1.4 for the Leica are great lenses for shooting in low light. Using a Leica you can normally shoot without camera shake with a 35mm lens at 1/30s, and Leitz lenses give good results at full aperture.

28mm

The 28mm is the first true wide-angle, and again a fine focal length for photojournalism. Apertures tend to be slightly less wide than for the 35mm, but depth of field is better. Working at f5.6 you can get sharp images of subjects between about 5 to 10 feet.

21mm, 24mm

With these ultra-wide lenses, it is hard to avoid some noticeable stretching of objects close to the edges of the frame. This so-called 'wide-angle distortion' is not really a distortion, but the natural consequence of imaging over such a wide angle with a rectilinear perspective. Lenses wider than 21mm begin to get difficult to use well. In crowds you tend to bump into the people you are photographing as you look at them through the viewfinder, and the wide-angle distortion can become extreme. Which can be fun!

Digital SLRs and Wide Angles

The smaller sensors of most digital cameras turn the moderate wide-angles to standard lenses, and the extreme wides to normal lenses. To get an extreme wide effect you need to work with something like a 12mm lens.

We may one day see truly affordable dSLRs with 35mm 'full-frame' sized sensors, but I doubt it. There is simply no need for them when a sensor half this size can deliver all the quality most of us ever need. It seems more likely that all manufacturers will standardize on the current smaller sensor size, and begin slowly to bring out a full range of lenses and bodies designed for the roughly 24x18mm sensors. The big market for dSLRs is among those who are new to the format, currently using comsumer digital cameras, not the minority with existing 35mm film outfits. Moving to the new sensor size will also give lens sales a boost as photographers need to replace existing lenses.

Using Telephoto Lenses

From Peter MarshallTelephotos Magnify

What are telephoto lenses?

Lenses that give a narrower angle of view than a standard lens are called telephoto lenses, though strictly speaking this is a particular way of making lenses. Most long focal length lenses in use on cameras today are telephoto lenses. Taking pictures through a telephoto lens is like using a telescope or binoculars - it makes everything look larger.

Narrow Field of View

These lenses have a narrower field of view than a standard lens. For 35mm format cameras we think of lenses from 70-120mm as short telephotos (often called portrait lenses), of those around 135-210mm as moderate or normal telephotos, and those of 300mm or more as extreme telephoto lenses. Details

The main use of telephoto lenses is enabling you to select a small part of the subject - to pick a detail. zSB(3,3);if(!z336){var zIsb=gEI("adsb");if(zIsb){zIsb.style.display="inli ne";zIsb.style.height="0px";zIsb.style.width="0px" ;}var zIss=gEI("adss");if(zIss){zIss.style.display="inli ne";zIss.style.height="0px";zIss.style.width="0px" ;}}
You also use them when you can't move closer to the subject - perhaps if there is a river or a busy road in the way.
Portraits

Short telephoto lenses are especially useful for impressive head and shoulder portraits. The working distance you need with them gives a natural looking perspective and makes it easy to get a sufficient depth of field to make the whole of the person's face sharp. Isolating the Subject

Moderate telephoto lenses are great for picking out details and isolating things from distracting material. Generally they are compact and light to carry, and fairly easy lenses to use, although you need to focus with care. Their limited depth of field can be used to make a subject stand out strongly against a confusing background by shooting at a wide aperture. Specialist Uses

Extreme telephotos are lenses for specialist purposes such as sports and wild-life. With 35mm, a 400mm lens lets you stand on the boundary of a pitch and photograph action in the centre. Extreme telephotos are much easier to use when the action will occur in a predictable place - with rapidly shifting areas of interest it is easier to use a moderate telephoto. Flattened Perspective

Telephoto lenses give a 'flat' perspective, reducing the impression of distance between different objects in the picture. This tends to create a more abstract effect. Camera Shake

Telephotos magnify your camera shake as well as the subject, so you need to use fast shutter speeds. The slowest speed you should use is 1/focal length - use the '35mm equivalent' focal length for other formats. With a 500mm lens, use 1/500 or faster, with a 135mm, 1/125 or faster. Use a tripod if you need slower speeds. Limited Depth of Field

Focus needs to be precise, as the depth of field of these lenses is limited, leaving little or no margin for error. Many people using or buying their first telephoto lens find their pictures are unsharp (you can read their comments in so-called 'user reviews' at many web sites.) Usually this is camera shake and incorrect focussing, and no fault of the lens.

Technology to the rescue

Two relatively modern developments have greatly improved the ease of use of telephoto lenses. First is autofocus, found in most modern cameras. Normally this will be much faster than manual focussing and more accurate, but you need to make sure you are focussing on the important part of the subject (normally the eyes in a portrait.) Often this will mean locking focus on this point (usually by holding the release half-way down) then reframing slightly to take the picture. Better cameras even have autofocus systems that will keep an object moving towards you in focus - so long as you keep it in the focus area in the viewfinder. These are great for following athletes and other similar moving objects - you can 'lock on' to the subject when it is some distance away and then fire the shutter release when the framing is correct.

The problem of camera shake has been attacked using vibration reduction systems, either built into the lens or the camera body. Mechanical systems use gyroscopically stabilised lens or mirror elements to keep the image still when you shake, while some digital cameras use digital image processing to achieve a similar result. Both enable you to shoot at slower shutter speeds - perhaps 2 speeds slower than with a normal lens of the same focal length - but will not compensate for a moving subject.

Size and Weight

Good, wide aperture long focal length lenses are large, heavy and expensive. Vibration reduction systems increase the cost considerably. Wide apertures not only make it possible to work in lower light, they also make the viewfinder image much brighter in SLR cameras, and focussing faster and more accurate - whether manual or auto. However for most purposes you can get great results from relatively small and cheap lenses. Zoom or Prime

Long focal length zoom lenses are relatively easy to design, and a good zoom lens is likely to be of similar quality to a fixed focal length. Zoom lenses give great flexibility and the control they give over framing is especially important in digital cameras, where every pixel counts.