The numbers on your camera each mean something different.
Camera lenses vary in focal length, aperture, construction, depth of field, focusing distance and special features. Lens markings will appear in a few different places on the lens. Lenses that are designed and manufactured for the professional market typically have more information on them than less expensive consumer-grade lenses. Understanding the markings on the lens is important not only to identify the type of lens, but also to know what size filters can be attached to them.
Instructions
1. Hold the lens and look on the top of the barrel near the back. On manual focus lenses there will be ring of numbers indicating the "f stop" position or aperture of the lens. On autofocus lenses, this function is usually controlled by the camera.
2. Look on the barrel towards the front of the lens. Note the window with numbers that change as the lens focuses. This is the focusing distance. There are usually two sets of numbers that give the focusing distance in feet and in meters.
3. Look at front of the lens to see a series of numbers around the perimeter. They indicate the focal lens. This number will generally appear with "MM" behind it. The starting aperture number begins with the letter "F." Another number on the front will be for the diameter of the front element. This tells you which filters you can attach because they are sold in different diameters.
Tags: focusing distance, front lens, numbers that