Nov 1, 2004

Wide Angle Lenses

From Peter Marshall,Your Guide to Photography.

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.

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 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.

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.