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Lens Calculator

Use this lens calculator to view the lens angle of view and the field of view of a lens. The angle of view of a lens depends on the lens focal length, and on the size of the sensor (or film) upon which the image is being projected (see the formula below for more). The lens field of view depends on the focal length of the lens, the size of the sensor, and the distance to the subject.

The lens calculator draws from a database containing most of the lenses currently being made by the likes of Canon, Nikon and Sigma, as well as a generic catalogue of popular lens focal lengths. Sensors include 35mm film, APS, medium format, and most of the current Digital SLRs on the market. If you are trying to choose a new wide angle lens or telephoto lens for your DSLR but are used to the 35mm world then this is for you.


To use the calculator, simply select a lens from the list, select a reading direction (horizontal, vertical or diagonal), and select a sensor type. The angle of view of the lens for the given combination is drawn on the adjacent graph, and the angle of view, field of view and 35mm equivalent lens are shown below it.

Lenses and bodies are grouped into catalogues. Use the "Select Catalogue" menu to load either the Canon, Nikon, Sigma or Generic photographic catalogues, or to load the CCTV/Security catalogue.

Lens Calculator by Gyre Technology

See also: Lens Calculator Lite Canon lenses, Canon EF-S lenses, Nikon lenses, Sigma lenses, Medium Format lenses or CCTV lenses, and About the lens calculator.

Lens Calculator News

31 December 2004: Added the Nikon D2X, Fujifilm FinePix S3 Pro, Kodak DCS SLR/n, and the Kodak DCS SLR/c to the database.

24 November 2004: I've finally added the EOS 20D to the calculator (it has a slightly smaller sensor to the 300D, 10D etc.), and I've moved the short-mount Canon EF-S lenses to their own catalogue.

9 July 2004: Canon CPS has just added a link to us in their Photographic Web Sites section :-)

6 May 2004: Gyre has made the lens calculator available for free in certain circumstances. Click here for further details.

3 February 2004: LensCalc Pro version 1.2 released. This release contains minor technical improvements.

2 January 2004: LensCalc Lite released - a lightweight version of the lens calculator. See the brand/application specific links above.

15 December 2003: Version 1.1 of the Lens Calculator is released. The calculator now displays the field of view of the lens at a given distance.

Lens Calculator Updates

I'm always trying to improve the lens calculator and am keen to hear your suggestions. If there is anything missing from the calculator or if you have any other useful feedback, please contact me with this form. I am particularly keen to hear about missing (or new) lenses and sensors.

Notes on the Lens Calculator

  1. The angle of view of a lens is calculated using the following formula:
    2 x tan-1( l / (2 x f) )
    where ' l ' is the length of the frame in the direction that you want the reading and ' f ' is the focal length of the lens.
  2. As the different sensors have slightly different aspect ratios, the "35mm equivalent lens" is calculated using the diagonal measurement of the current sensor against that of 35mm film.
  3. Sensors included in the calculator catalogues are:
    35mm film
    APS film APS - H, APS - C, APS - P
    Medium format 645, 6x6, 6x7
    Canon EOS 1DS, EOS 1D, EOS-1D Mark II, EOS 10D, EOS 300D & EOS 20D
    Fujifilm FinePix S1 Pro, FinePix S2 Pro, FinePix S3 Pro
    Kodak DCS 14n, DCS SLR/n, DCS SLR/c
    Nikon 1DX, D2H, D2X, D100 & D70
    Pentax *ist D
    Sigma SD9 & SD10
  4. Angle of view is displayed in degrees and minutes. There are 60 minutes in a degree, and 360 degrees in a full circle. The notation 96°43' means 96 degrees, 43 minutes.
  5. Certain lenses (notably fisheye lenses) have been omitted from this calculator.

Further information about the Angle of View Calculator

The angle of view calculator was developed by myself while working for Gyre Technology. Gyre has kindly let me publish it here.

There are several versions of the calculator, including the Pro and Lite versions that can be found on this site. For further details on these versions, for licensing information and for further technical details, please visit the the lens angle of view calculator home page.