For the supported formats it will calculate the hyperfocal distance, near and far depth of field and total available depth of field for the lens specified. As well as the equivalent lens in one of the other supported formats. Where the equivalent lens produces the same depth of field and perspective.
Note: The experimental values are prat of an ongoing an experimental concept that I’m currently developing. Please don’t contact me and ask me what it is or how to interpret it. It is only included and displayed so I can move forward on developing an idea.
2011-01-17: I’ve added some features to make computing AF calibration data easier. The first is the AF Test Dist button that sets the focus distance to the minimum recommended AF test distance of 50 times the focal length. The second is the addition of a 1/8th DoF measure to the outputs.
2014-01-12: Added support for metric distance input and output formatting. And support for preset focus distances roughly corresponding to various types of portraits.
2014-01-28: Added angle and field of view calculations. Angle and field of view are show for the selected format (i.e. 35mm or APC-S) and may not reflect the exact angle or field of view for the equivalent lens if the platforms aspect ratio is different.
2014-02-03: Clicking on the format in the equivalent lens chart will update the lens setting to match that format as closely as the calculator allows.
2014-02-05: Added 1/1.7″ CCD used in many compact cameras and the Pentax Q mirrorless cameras.
2014-05-13: Updated script to use the same engine used by tools.pointsinfocus.com/dofcalculator and to store current settings in the URI to allow linking to a specific setup.
2016-04-01: Updated to allow the use of a custom frame size or crop factor. Enter the custom frame size or crop factor in the “Custom frame size box”.
You can enter a frame size in mm as width x height (eg. 24 x 12), decimals are permitted. Don’t specify the “mm”, and spaces around the x are ignored. The crop factor is calculated internally as the diagonal as referenced to the diagonal of a 35mm (36×24) frame.
You can enter a custom crop factor as a decimal number. Numbers >1 (e.g. 1.5) result in a frame that’s smaller than 35mm. Numbers <1 (e.g. 0.5) result in a frame that’s larger than 35mm. In this mode the aspect ratio of the frame is assumed to be 3:2. If you want a different aspect ratio frame, you’ll need to specify the dimensions directly.
2017-03-13: You can now enter a custom aperture value that isn’t in the standard apertures list. There is currently an outstanding bug on with this in that it doesn’t persist correctly through the URL hash (# at the end). However, the calculations using it are done correctly.
Also I’ve reduced the precision of the stored aperture values, so some results may be slightly different form previous versions.
DOF and hyperfocal distances are calculated using the following formulas.
Equivalent lenses are calculated so that the focal length produces the same approximate angle of view and the f-stop results in an aperture diameter equal to the base lens’s aperture diameter.
As of April 2016, the calculator now supports custom frame sizes. These can be entered as either a crop factor or as the dimensions, in mm, of the frame to be used.
For crop factors, the reference frame is the 3:2 aspect ratio 135-format (i.e. 36 x 24 mm) film frame. Cropped frames will retain the 3:2 aspect ratio. Crop factors are crop of the reference frame, therefore a value larger than 1 will produce a smaller frame. Entering a value smaller than 1, e.g. 0.5, will generate a frame larger than the reference frame.
The second option is to enter the dimensions of the frame in mm. This should be entered in the format of “width x height”, or “dimension_1 x dimension_2”. Whether the width precedes the height or vice versa will only change the horizontal and vertical values presented in the angle and field of view sections. Spaces between the numbers and the ‘x’ are ignored. Decimal values are accepted.