Can you see what the following pictures have in common?
No, it’s not the cathedral or the soybeans. They are all essentially the same picture. Why?
I read something the other day that jogged my memory about zoom lenses. The author was saying how great they are for bringing distant subjects closer but they don’t really change perspective. To do that you have to change the actual distance between camera and subject – basically move your feet. And new perspectives can make all the difference for compositions.
The images above were taken with a 50mm, 75mm and 150mm lens on the same camera. The somewhat odd color is due to the film I was using, a B&W film that is processed like color negatives. The film has nothing to do with my point – I just like the color cast!
I shot the three from the same point, simply changing lenses with each shot. Don’t see how they are the same? Look at these crops.
These are the 50mm, 75mm and 150mm images above cropped to show the same portion of each image at the same size. Look at the relationship between the two trees framing the cathedral and the building itself. Notice the perspective doesn’t change – the trees are the same distance from each other and the building in each image. Although I changed prime lenses I would have gotten the same result with a zoom lens set at each of these focal lengths.
Suppose I wanted the trees to appear farther apart, or closer to me than they are? I would have had to walk closer to them to change the perspective. Doing so would have also made them look bigger than the cathedral.
BTW, this is also what’s behind the “crop” factor you read about for sensors less than full frame (or the size of a piece of 35mm film). A lens of a given focal length will cast a circle of light on the sensor that’s the same size regardless of the size of sensor. Smaller sensors ‘see’ a smaller part of the image – they ‘crop’ the image to their size. What you see looks as if it was shot through a longer lens. Thus, for a 2x crop factor camera (like the Four-Thirds system), using a 50mm lens results in an image that looks like it was shot through a 100mm lens. Again, perspective doesn’t change, just the amount of the image you see.
The moral of the story? Yes, zoom lenses are much better now than 20 years ago – faster, sharper, probably lighter. But in order to bring variety to the look of your images you still need to use your legs to work the scene.