focal length


Definition of focal length

: the distance of a focus from the surface of a lens or curved mirror

Examples of focal length in a Sentence

Recent Examples on the Web But the effect can also be achieved with a DSLR using inexpensive extension tubes that change the focal length of an existing lens. A.j. Herrington, Forbes, "Weed Porn: Focus On Cannabis Photography," 25 Feb. 2021 Where the Max does trump all the other iPhone cameras is with its zoom lens, which comes in tighter, thanks to its 65mm focal length, an increase over the 52mm on the 12 Pro. Jefferson Graham, USA TODAY, "So you want a new iPhone? Apple's got 7. How to choose the right one for you," 13 Nov. 2020 The larger the focal length, the smaller the field of view. Cameron Johnson, Popular Mechanics, "How To Get Started in Astronomy," 10 Nov. 2020 The focal length is 65mm, up from the 52mm offering on the other iPhones with an advanced telephoto offering. Jefferson Graham, USA TODAY, "iPhone 12 Mini and 12 Pro Max begin preorders Friday, both expected to be in short supply," 6 Nov. 2020 There's an Ultra Wide camera, a Telephoto lens with a longer focal length than last year's models, and Wide cameras that take better photos and videos in low-light settings. Courtney Linder, Popular Mechanics, "Should You Buy the New iPhone 12?," 13 Oct. 2020 Gskyer astronomical refracting travel telescope ($95.99) with 70mm aperture, 400mm (f/5.7) focal length, phone adapter and wireless remote that lets beginners explore the stars and moon can be transported in its carry bag. oregonlive, "Amazon best sellers – what everyone is buying on sale for summer and maybe you should too," 5 July 2020 Lenses with a shorter focal length enabled Galileo to squint at insects as well as planets. 1843, "How stargazing could save your life," 2 July 2020 That design effectively extends the apparent focal length of the image (which is key to user eye comfort) without the need for a large physical space for the light to travel through. Kyle Orland, Ars Technica, "How holographic tech is shrinking VR displays to the size of sunglasses," 30 June 2020

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'focal length.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of focal length

1682, in the meaning defined above

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Time Traveler for focal length

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The first known use of focal length was in 1682

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Last Updated

13 Mar 2021

Cite this Entry

“Focal length.” Dictionary, Merriam-Webster, Accessed 10 Apr. 2021.

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More Definitions for focal length

focal length


English Language Learners Definition of focal length

technical : the distance from the surface of a lens to the point of focus (sense 3)

focal length

\ -ˌleŋ(k)th How to pronounce focal length (audio) \

Medical Definition of focal length

: the distance of a focus from the surface of a lens or concave mirror symbol f

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