Opinion: Why a telephoto lens does more than just get you closer
When I teach photography, a key question I always ask my students is “What’s the purpose of a telephoto lens”? Without fail, most will say something like “To get closer to the subject” or “To fill more of the frame with the subject”.
And yes, while a telephoto lens will help you do this, for me that’s often not the reason I use one. With today’s high megapixel cameras, depending upon the end resolution you need, you can often “…get closer…” or “…fill more of the frame…” simply by cropping in post-production, or putting a full frame lens on a cropped sensor camera (which really is a type of cropping, it’s just pre vs postproduction).
But I find that the real creative advantage of using a telephoto lens is they allow you to compose the background differently, by reducing the field of view and adding what is known as compression – more on that in a minute. First, to understand what I'm talking about - where telephotos are used to simply get closer - let’s look at the image below.
This is a series of photos of Sandringham beach with Red Bluff cliff in the background, shot from the same position but using different focal lengths. The main difference you'll really notice is that as I have increased the focal length, the closer the cliffs appear, and the less of the surrounds you see. But as I mentioned, a lot of the time, to some extent, you can often achieve the same 'closeness' by cropping in.
Here’s where they really come into their own. In the image below where I am using a 16mm lens, you can see Gravel, my old Teddy bear, is filling the central part of the frame, sitting patiently to be photographed in my open plan living area, guitars on the left, fridge on the right.
But if I move away, increasing the focal length whilst keeping Gravel the same size in frame, what you’ll notice happening is three things. Firstly, the field of view decreases, so we see less of Gravel’s environment. In this case, as we move past 50mm we now don’t really know where he is.
Secondly, some parts of Gravel’s environment that we couldn’t be seen before, are now revealed. We start to see another (and much older) teddy bear named Griz, sitting behind him. And finally, the background that we could and couldn’t see, appears closer than it really is. This characteristic is known as compression, and that happens whenever we use telephoto lenses.
So, by changing to a telephoto lens, whilst keeping the main subject in the frame the same size, we start to change the background composition significantly, and in doing so, the information we are providing and the story we are telling. And of course, if you use a telephoto lens and shift to a wide angle, the exact opposite happens.
Many people use the term ‘zoom’ and ‘telephoto’ interchangeably, but they are very different creatures. A zoom refers to a lenses ability to change, or slide through, different focal lengths, regardless of what focal lengths they are. A telephoto however, normally refers to any lens, with a focal length greater than about 70mm.
So, a 70mm-200mm lens for example (full frame equiv.) would be considered both a zoom lens and could also be called a telephoto lens, whereas a 16-35mm would be called a zoom (or wide-angle zoom), but is definitely not a telephoto.
And, speaking of telephoto focal lengths, normally a lens that sits between 70mm to 200mm is referred to as ‘medium telephoto’, whereas those over 300mm are called ’super telephotos’.
All else being equal, lenses over 300mm are normally larger, heavier and much more expensive than shorter focal length lenses, with some priced north of $15,000.
This is due to their complex optical designs, multiple lens elements and coatings, and the high quality of these glass elements, along with the general superior construction and quality that photographers who use these specialised tools demand.
Now, this of course assumes you have the ability to move relative to the main subject, and that’s not always possible. Sometimes you just can’t move. but if you do have the opportunity to change positions, this gives us the opportunity to significantly alter the composition and the story we are telling.
So maybe next time you think about reaching for that telephoto lens, stop and ask yourself “What would happen to my composition and the story I was telling if I just moved a little closer, or stayed where I was, and cropped later in post?” You might find that the stories your pictures tell are very different, and I’d even suggest, often more interesting. ❂