In this page following details are mentioned.

FOCAL LENGTH (MM) 11/16 - 7-7/8"

35 MM EQUIVALENT FOCAL LENGTH (APS-C) 1-1/16 - 11-13/16"

what do these mean?


The focal length of the Sony E 18-20 lens is 18mm to 200mm, as per the lens name.

Since it is designed for an APS-C sensor, it gives the same field of view as a 27-300mm lens which is the 35mm Equivalent Focal-Length.

This is what it says on the Product Details section of the lens page as you can see here. Unfortunately it appears you found a page with errors since those are not the same numbers quoted in your answer. This is what is currently shown in the Full Specifications page. Hopefully Sony will correct it.


As pointed out in comments, the exact error is that the specification is display as inches and fractional part but the measurements are exactly the same. This happens from both the USA and from Canada which uses the metric system, so it definitely is a bug in the website. I tried yesteday from Miami and today from Montreal and got exactly the same output.

  • For some reason, Sony's spec page is listing focal lengths in fractional inches (even though the label says "MM"). So they are the same numbers, just in a weird format. My hunch is their website localization engine is just blindly converting all measurement numbers to the locale's preferred units (imperial, for US sites, probably), and is not excluding numbers that should always be left in metric, such as focal length. – scottbb Feb 7 '17 at 19:35
  • Interesting. I'll double check in a few hours as I'm on my way from the US to Canada :) – Itai Feb 7 '17 at 20:05
  • ya know, there are ways to check different locales of websites, than by actually traveling to another country to check it! =P – scottbb Feb 7 '17 at 20:49
  • @Itai Also, by clicking "Full Specifications", again it gives those numbers. – user152435 Feb 8 '17 at 2:43
  • 1
    The double-quote mark following numbers is the notation for inch. Thus 7 ⅞" = 7 ⅞ inches = 200.03mm. 1 ¹⁄₁₆" = 26.99 mm. 11 ¹³⁄₁₆" = 300.04mm. – scottbb Feb 8 '17 at 13:12

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