But if I zoom all the way to 35mm, my maximum aperture becomes f/4.) (At the lens’s widest, 17mm, I can open the aperture to f/2.8. What does this mean? It’s simple: the maximum aperture on the 85mm lens is f/1.8, and on the Tamron zoom, the maximum aperture changes from f/2.8 to f/4 as you zoom the lens. On the Tamron, you should see “1:2.8-4,” and on the 85mm, you should see “1:1.8.” In the photo below, you can see two different lenses: my Tamron 17-35mm and my Canon 85mm. On the front of the lens inside the filter ring area.You can usually find this information in one of two places (or perhaps even in both): Now, pretty much every lens has the maximum aperture written somewhere on its body. (Note that some zoom lenses have a variable maximum aperture, where the maximum aperture will change depending on the focal length this is represented as a range of numbers, such as f/3.5-6.3.) So the best lenses – and the most expensive lenses – tend to offer a very wide maximum aperture. Larger apertures like f/2.8 or even f/1.8 are highly desirable because they allow you to shoot in low-light conditions while maintaining a fast shutter speed. Note that the larger the aperture opening, the smaller the f-number (so f/2.8 corresponds to a very wide aperture, while f/22 corresponds to a very small aperture).
The maximum aperture is the largest aperture opening your lens is capable of achieving. For example, if your lens is a 70-200mm zoom like mine (below), you’ll see markings that span from 70mm to 200mm. Next to this ring, you’ll generally find focal length numbers. Zoom lenses feature a zoom ring twist it, and your lens will zoom in and out. In this section, I’ll discuss numbers frequently found on newer lenses (though note that many will apply to old lenses, as well!). Common numbers on newer digital lensesĭepending on the age of your lens, you’ll run into different markings. I’ll explain what the numbers actually mean, and I’ll also explain why they matter for your photography.īy the time you’re finished, you’ll be a lens number expert, and you’ll never find yourself confused by your lens markings again. That’s why, in this article, I’m going to run through all the important camera lens numbers you’ll encounter. Camera lenses include quite a few numbers – and many of these are often confusing or obscure, especially for beginners.