The Telephoto Lens

The Telephoto Lens

by William Lulow

Note: Looking back through the last year or so of articles, I saw that I didn’t have an article about telephoto lenses, specifically, so I thought I’d include one here. 

Telephoto lenses are very particular tools to keep in your photography tool kit, but they often have limited use. Therefore, they aren’t lenses that you would want to use all the time. Photographers use them for several reasons:

1. To bring distant subjects a bit closer
2. To isolate subjects from the background using shallow depth-of-field afforded by longer lenses
3. To render sharp detail on ONE SUBJECT only
4. To make portraits more proportional to the face’s actual sizes
5. To reduce the coverage of a scene and focus (no pun intended) on one element

These are the basic reasons for using long, or telephoto lenses and these are the things they do best. So, they are not lenses you might want to carry around with you everywhere you go. They are for very specific tasks. Most TELEPHOTO LENSES are:

1. Heavy to carry because of the large pieces of glass with which they are made
2. Restrict Depth-of-Field
3. Restrict Angle of view
4. Not as fast (able to transmit a lot of light, because they have smaller maximum apertures

Here is one I like to use. It is the 135mm f/2 lens which, on my crop sensor Canon camera, acts like a 216mm lens:

This lens is long enough to get close to most action and long enough to isolate a subject from the background, without being too heavy or cumbersome. If you are a sports photographer, you might want to use a longer lens because you often wouldn’t be able to get close enough to the action to record a player’s facial expressions, say. Here is a really long, telephoto lens that you might not want to carry with you everywhere you go:

This is a 600mm, f/4 lens. It must be mounted on a tripod. So, the lens is mounted first, then the camera is attached. This is a highly specialized lens which also costs about $14,000! My usual caveat about this kind of equipment is: don’t buy it if you don’t use it every day! There are places where you can rent unusual equipment like this for specialized kinds of assignments. Back when I was shooting golf tournaments for the LPGA, I actually borrowed a 600mm lens from Canon directly. They had a professional “loan program,” at that time. I don’t think it’s available today. 

As I have detailed in previous articles about zoom (variable focus) lenses, these lenses are tricky because you use them without always considering their effects. Once you zoom (or rack out) your lens to its maximum length, it changes the characteristics of the lens. This is something most photographers don’t consider when they just want to bring a subject closer. When you use a zoom lens at maximum length, you are automatically narrowing the coverage angle, the depth-of-field response as well as the overall speed of the lens. As I said, because of the size of the glass involved in making these lenses, their light transmitting capability is limited. So, the decrease in the lens’ speed will cause you to have to put the lens on a tripod, use the lens wide open (which may produce less sharp images), increase the ISO to compensate or maybe even use a slower shutter speed, which to most action photographers is unacceptable. 

So, make sure that you actually need a really long lens for the subjects you photograph regularly before investing in a behemoth like this! 

With all this said, here are a few images I have made with my 135mm telephoto lens as well as an older 200mm Nikkor lens:

The longer telephoto lenses definitely have their uses. And, as I have noted previously, the prime telephotos are often better and sharper than zooms. You also are much more aware of what you have to do to use them correctly. It’s not just a matter of zooming the lens out to get closer. You have to be aware of exactly the things that telephoto lenses do best. They can bring subjects closer but in doing so, they limit the field of view, they require more exposure which means that you may have to increase ISO settings. So, make sure that you understand these things before you begin shooting with your telephoto lenses.