Zoom lenses have changed photography. Not exactly a news flash, is it? The first zoom lens was patented in 1902 for the motion picture industry. It took a while but zoom lenses became pretty much standard issue in the late 1970’s to early 1980’s as they became the ubiquitous “kit lens”. Today for all of their popularity there is little written about how to use zoom lenses effectively.
Using a zoom lens sounds like the easiest thing in the world. On an interchangeable lens digital camera the photographer twists or pushes out on the lens to increase the magnification. On a compact digital camera the photographer doesn’t even have to exert that much effort, a mere push of a button extends and retracts the zoom lens. That simplicity in use is the beauty of the zoom lens. It’s hard then to believe that it is this same zoom lens that can be the curse of good pictures everywhere.
What zoom lenses bring to the table for the photographer is a much smaller camera bag. Rather than lugging around a body and three or more fixed length lenses one zoom lens can replace them all. Some folks think that zooms also mean more time taking pictures and less time swapping lenses, but that statement may not be as accurate as we think.
A zoom lens makes it easy to sit in one place and reach out with lens magnification to capture the world. And in fact that is how a zoom lens is most often used. I have seen tourists hit the ground right out of the car and shoot a dozen or more images of some scenic spot without moving anything more than their zoom lens. They may have documented their arrival but their pictures will probably be flat and boring.
While zooming a lens from wide to telephoto draws subjects in closer, the action also changes the perspective of the scene. Let’s imagine a beautiful meadow full of yellow flowers, in the middle distance is a stand of leafy green trees. Your daughter is 30 feet away standing in front of the scene and it’s time to take a few pictures.
We could zoom the lens in on the young lady from 30 feet away to get a nice ¾ shot from head to knees. This is the most common way photographers will shoot in this situation. Less common would be to walk about 12 to 15 feet closer to your daughter before snapping the shutter. We would still have a nice ¾ composition. Depending on which choice we made we will be either underwhelmed by the resulting image or our socks could be knocked off.
If we compare the two possible images side by side we notice right off the bat that the image captured while zooming from 30 feet away may give us a nice shot of the subject but the image looks flat. The other image taken by physically moving in closer in comparison looks like it has some depth and it isn’t flat at all. What has happened is that we have the same scene with two different perspectives.
Zoom lenses will not only magnify a subject but as the lens gets longer the near and far objects in a scene compress closer together. This foreshortening of distances creates a flatter image with less depth. On the other hand the image we took while standing closer to the subject didn’t require as much magnification and therefore the objects in the scene didn’t compress. The image has a much greater feeling of depth.
You can prove this yourself. Have a subject stand 20 to 40 feet in front of some trees. Zoom your lens out all the way and move yourself back and forth until the subject appears from knees to top of head in the viewfinder. Snap the shot. Next set the lens length to a setting almost at the lenses widest. Now move your camera in until the subject once again fills the same space in the viewfinder, snap the shot. Compare the images side by side and you will immediately see the difference. The subject is the same size in both but in one the background appears much closer which eliminates the feeling of depth in the image.
There is an old adage in photography: If you want better pictures get in closer. And said another way: When you think you are in close enough take another step closer. These are suggestions to move the camera in closer not to zoom the lens.
The other side of the coin is to make zoom lens compression work for the photographer. One example is with portrait photography where a slight telephoto length renders the human face pleasingly in a two dimensional print. For DSLR’s that length is around 50mm to as much as 85mm. If the photographer is shooting film or a full-frame digital camera think 85mm to 105mm for great results.
If you are shooting a sports event such as soccer or football a long zoom lens is ideal. It’s just not possible to get close to the action under these circumstances. However since we know that the longer zoom length will compress the distance between subjects we can use that to our advantage. Shooting from the sidelines or the first few rows of bleachers can make the players seem closer together and give the final image a sense of “being in the huddle”.
Oh, and as far as a zoom lens saving the time that would be required for swapping single focal length lens on the camera body? Take a look at the last event you shot.
- If it was a football game I’ll bet that over 90% of your images were at or near the longest telephoto setting of your lens.
- If it was a diner party I’d bet that the same 90% of the shots were at the widest setting. 3)
- If it was any other event I’d bet that a camera with a standard lens could have taken almost every image simply by moving the camera closer or further away from the subjects.
So if the correct single focal length lens is on the camera in the first place there really won’t be any time dedicated to swapping lenses.
In conclusion: Zoom lenses are useful tools but if not used judiciously they could actually make our pictures look worse. Always try to get as close to the subject as possible rather than relying on the zoom lens to bring them to you. By using the zoom lens to magnify the subject we are also compressing the distance between near and far objects in our scene. Zoom lenses are ideal tools for situations where it is not safe or practical to get closer to the subject. Under some circumstances it is possible to make zoom lens compression work for us, such as while shooting a football game or at a zoo.