How to Use focal length in a Sentence

focal length

noun
  • Over time, though, lenses came to be measured by the distance of their focal length.
    — Allain Daigle, The Atlantic, 13 May 2018
  • The focal length should be labeled somewhere on the eyepiece.
    — Mike Lynch, Twin Cities, 14 Jan. 2024
  • The compact model gave him the right match of focal length and sensor size for concert pics.
    — Kevin Purdy, Ars Technica, 17 Jan. 2025
  • Any eyepiece with a focal length in excess of 20mm is fine for low-power views.
    — Anthony Wood, Space.com, 15 Nov. 2025
  • Fine details may also be captured by using a zoom lens at a medium focal length.
    — Deanna Chandra, San Diego Union-Tribune, 13 Nov. 2021
  • The focal length of a telescope is the distance from the objective lens to the focal point.
    — Jamie Carter, Space.com, 30 Nov. 2025
  • Its inner barrel telescopes out to zoom in to tighter focal lengths, extending by about an inch.
    — PCMAG, 2 Dec. 2024
  • Wide-angle lenses have a shorter focal length than standard lenses and provide a wider field of view.
    — Brandon Russell, Popular Mechanics, 29 Mar. 2023
  • Lenses with a shorter focal length enabled Galileo to squint at insects as well as planets.
    — 1843, 2 July 2020
  • With a focal length of up to 160mm, the Petzval lens was key for flashback scenes.
    — Jazz Tangcay, Variety, 2 July 2022
  • Four of them have a short focal length, which translates to a relatively wide field of view, while the other two have a longer focal length.
    — Mike Wall, Space.com, 13 Mar. 2025
  • Aperture is measured in f-stops, which is a ratio of the focal length divided by the size of the camera’s opening.
    — Maren Estrada, BGR, 5 Aug. 2021
  • This creates enough separation between the lens and the sensor to enable the longer focal length.
    — Jay Peters, The Verge, 18 Sep. 2023
  • The shift from lens width to focal length likely arose in Hollywood for reasons of precision.
    — Allain Daigle, The Atlantic, 13 May 2018
  • The focal length is a short telephoto for the sensor size, with an angle of view that's just about the same as an 85mm full-frame prime.
    — PCMAG, 5 Mar. 2025
  • The 35mm focal length is a classic perspective and is a perfect focal length for many subjects.
    — Harry Bennett, Space.com, 27 Aug. 2025
  • In this equation, s stands for sensor dimension in millimeters and f is the focal length of the lens in millimeters.
    — Michael E. Bakich, Discover Magazine, 24 Feb. 2024
  • As scientists carefully select the focal length of the laser optics, the probe can increase or decrease its rate of speed.
    — Discover Magazine, 12 Feb. 2019
  • The location of the image depends on the properties of the lens (the focal length) and the distance from the object to the lens.
    — Rhett Allain, Wired, 2 May 2020
  • The huge camera module houses a moving prism to switch focal length, which looks like an engineering marvel when put to use.
    — Prakhar Khanna, Forbes.com, 15 Aug. 2025
  • Additionally, by blinking, the lenses can change their focal length, which amounts to being able to zoom in and out just as users do on their phones.
    — Maria Pasquini, PEOPLE.com, 29 July 2019
  • The macro photos can be shot as 48-megapixel files, but all the other focal lengths have smaller sensors due to the cropping.
    — Jakob Schiller, Outside, 23 Sep. 2025
  • The lens also has a focal length of 35mm, which is a more optimum focal length for photography.
    — Ben Sin, Forbes, 3 Mar. 2025
  • Choose a telescope with the largest possible aperture (expressed in inches and millimeters) and a long focal length.
    — Jamie Carter, Space.com, 30 Nov. 2025
  • The downsides to this lens are minimal but there are reports of barrel distortion at the 17mm focal length.
    — Harry Bennett, Space.com, 27 Aug. 2025
  • Distortion is also impressively low for such an ultra-wide focal length.
    — Tantse Walter, Space.com, 18 Feb. 2026
  • The notes in the margins of that shooting script are full of lens focal lengths, camera angles, and distances that were key to the compositions of shots.
    — Sarah Shachat, IndieWire, 28 Feb. 2026
  • Supporting this is a multi-camera array designed to work across various focal lengths.
    — New Atlas, 27 Apr. 2026
  • But at the right focal length, the image will be perfectly in focus in both directions, and that gives the cat an extra way of judging distance.
    — Helen Czerski, WSJ, 22 Oct. 2021
  • For this, use a wide-​angle lens, with a focal length from 14 to 24 millimeters, with your camera on a stable tripod.
    — Eric Adams, Popular Mechanics, 15 July 2022

Some of these examples are programmatically compiled from various online sources to illustrate current usage of the word 'focal length.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

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