How to Read a Camera Lens

When it comes to buying a lens for your digital camera, the sheer number of options, specifications, abbreviations, and features are enough to make anyone who gets discouraged throw up their hands and resort to simply using their smartphone. But special cameras are still worth it and allow you to capture high quality photos that smartphone cameras simply cannot match their tiny sensors. Once you know what you are looking for and you know how different companies label the same specifications, it is not that hard to determine what type of lens you need. With a little education, you will be able to determine which features in your new lens are unnecessary, necessary, or simply useful.


The aperture on a camera lens works the same way as your pupils, opening depending on how much light you want to hit the camera sensor. The maximum aperture of your camera lens, measured in “f-numbers” or “f-stops,” is usually indicated the same on all lenses. The aperture range can range from f / 1.0 to f / 22 depending on the lens. You will find variations in the presentation – for example, sometimes f / 2.8 is displayed as “1: 2.8”, but the numbers indicate the same thing: the maximum aperture of your lens.

The lower the number (for example, f / 1.8), the wider the aperture and the more light your lens lets through. Small aperture lenses (which allow more light to hit the sensor) also create blurry bokeh. ideal for portraits. If you’re using a zoom lens, you’ll see the maximum aperture range instead, like f / 3.5-4.5. The two aperture numbers represent the largest aperture available in your camera’s zoom range. The more you zoom in, the smaller your maximum aperture (resulting in a higher aperture number of 4.5).

Focal length

The focal length of the camera lens (the distance from the most focused image of the lens to the camera sensor itself) is recorded in millimeters. Lenses that do not have a zoom function (for example, a 35mm fixed focal length portrait lens) have one focal length, while zoom lenses use two numbers (for example, 18-55mm) to indicate the focal length range. lens. The shorter the focal length, the more of the subject you can capture in the photo. This is why wide-angle lenses have a focal length of 10 to 30 mm. The focal length number (or range) can be found on almost every camera lens and is often found next to the lens aperture number.

Lens diameter

You can use filters on your camera lens to reduce glare, or filter out colors for interesting effects. To do this, you need to know the diameter of the lens. It is measured in millimeters, just like the focal length of the camera, and is next to the ø symbol, which represents the diameter. The lens diameter is most often indicated on the front of the camera lens or engraved on the side near the top where you screw on the lens filter.

Automatic or manual focus

Auto focus (relying on either a slower focusing motor or a more advanced, quieter “ultrasonic motor”) allows you to keep your subject in focus without manually adjusting the camera’s depth of field. If you see a lens with a switch labeled “AF / MF,” that means you can quickly turn the feature on – or turn it off if you want a specific look in your photos or want more control over depth of field in a controlled environment. for example in the studio.

Brand-specific jargon

The more interesting features of a camera lens are often hidden behind proprietary jargon. However, don’t let the abbreviations fool you. While abbreviations may differ from camera to camera, the technology behind the functions is largely identical.

Optical image stabilization

Optical Image Stabilization is a feature found in both lenses and camera bodies that tries to counteract vibration and other tiny movements that can blur photos. Image stabilization produces sharper images, especially when shooting at wider apertures than lenses without image stabilization. Here are the abbreviations you’ll find in these brands:

  • Sony: OSS (Optical Image Stabilizer)
  • Nikon: VR (Vibration Reduction)
  • Canon: IS (Image Stabilization)
  • Sigma: OS (Optical Stabilization)

Full frame touch lens

Full-frame cameras use larger, full-frame sensors to let more light into the camera for better quality photos. To use the entire sensor, you need a full frame lens. Some full-frame cameras support cropped lenses, but this cropped lens, designed for a smaller sensor, will result in photography that uses less of the area of ​​the full-frame sensor. Full frame lenses are generally more expensive than their cropped counterparts. You can read about the nuances of full-frame cameras and lenses if you are drawn to the idea of ​​higher image quality (and more expensive equipment).

  • Sony: FE (mirrorless)
  • Nikon: FX
  • Canon: EF
  • Sigma: DG

Clipped sensor lens

Cropped image cameras are commonly used in cameras intended for the consumer or hobbyist. They don’t have the same image quality as a full-frame sensor, but they still boast better image quality when compared to devices such as a smartphone.

  • Sony: E (mirrorless)
  • Nikon: DX
  • Canon: EF-S
  • Sigma: DC

Ultrasonic autofocus motor

Ultrasonic motors provide quieter, faster focus adjustments, keeping the image in focus more accurately than the slower electronic motors found in less expensive lenses.

  • Sony: SSM
  • Nikon: SWM
  • Canon: USM
  • Sigma: HSM

Professional grade lens

Professional grade lenses are incredibly accurate and more durable than consumer grade lenses. They have better glass, faster autofocus motors, and often have built-in water and dust resistance. Professional grade lenses are usually designed for full-frame cameras and take advantage of the full-frame sensors internally.

  • Sony: G
  • Nikon: Professional grade lenses are identified by a gold “ring” around the lens.
  • Canon: L
  • Sigma: EX

Low dispersion lens

Low dispersion lenses seek to eliminate the problem of chromatic aberration, a property of cameras that causes color shift in photographs due to imperfect refraction of light. This usually happens around the edges of the photo. There is software to correct chromatic aberration, although most people will not notice the color change unless they are professionals. Low dispersion glass lenses seek to eliminate this problem by using a variety of lens manufacturing technologies.

  • Sony: ED
  • Nikon: ED
  • Canon: ED
  • Sigma: APO


Leave a Reply