This page contains several calculators of use to photographers.
All of the calculators are written using Javascript, which means
you'll need a Javascript enabled browser (IE/Netscape/etc.) to use
this page. It also means that you can download/save this page to
your computer and use the calculators without being connected to the
internet. Fields displayed on the left of the
"compute" button are for user input. Fields on the right of the "compute" button are where
the results are displayed. 



This version includes additional calculators written by Alan Fletcher, using formulas and functions from the original, with the permission of Max Lyons. Those written entirely by Max Lyons are identified as Max's and those written (or substantially modified) by Alan Fletcher are identified as Alan's
[ Coming soon: After you have pressed the Compute button the Bookmark link underneath it is updated, so that you can return to the calculator with these values. You can either leftclick on the bookmark link to reload the page, or rightclick to open a new window, copy the link location to the clipboard, or perform other operations in your browser.]





This calculator computes depth of field for a single aperture and focal length, and also generates a table of 'reverse depth of field', giving the aperture needed for a variety of cameras. See below for details.

This calculator computes depth of field, based on aperture,
focal length, distance to subject and Circle of Confusion (CoC). A
CoC of .03 is generally accepted as appropriate for a 35mm camera.
At the top left, fill in various parameters.
When you press the Compute button two calculations are performed:
At the top right:The input parameters are used to perform a single calculation, using the specified Distance, Focal Length and Aperture.
For these, only the Circle of Confusion is scaled using the specified Focal Length Multiplier.
In the table below:
The input parameters are used to perform Reverse Depth of Field calculations for a number of different cameras.
For these the Focal Length and Circle of Confusion are scaled for the camera format. For each entry in the table the depth of the NEAR Infocus point is used to calculate the required Aperture.
Apertures below F1.0 and above F30 are grayed out.
In addition, it computes the diffraction Airy Disk for each aperture. If this exceeds the Pixel Size by a specified factor, then the background is Yellow, and if it exceeds the Circle of Confusion by that factor then the background is Red. The default diffraction threshold of 2.69 was chosen so that diffraction effects start to show at F11 on a Nikon D200.
See some excellent examples at Lloyd L Chambers : Diffraction—A Technical Challenge  he suggests that the maximum aperture for the 1D III is F11 : use a threshold of 2.0 in this calculator.
This calculator incorporates many of the formulas and functions from Max Lyons' original calculator, and is used with his permission.



This calculator computes depth of field, based on aperture,
focal length, distance to subject and Circle of Confusion (CoC). A
CoC of .03 is generally accepted as appropriate for a 35mm camera.
For most modern digital SLR cameras (e.g. Canon D30/D60/10D/20D/30D,
Nikon D100/D50/D70/D200, Fuji S2), a smaller CoC is probably more
appropriate. Because the sensor size on these cameras is smaller
than a 35mm negative, the image must be enlarged to a greater extent
for any given print size. A CoC of 0.019 is a reasonable value for
these cameras. For small, pointnshoot digital cameras (e.g. Canon
A620, Canon G6) with a 1/1.8" sensor (7.18 x 5.32 mm), a value of
about 0.006 is appropriate. 


This calculator computes the degree of parallax error that
occurs when a camera is rotated around a point that isn't the nodal
point. This is useful for photographers who take a sequence of
images to be stitched into a panorama. The Nodal Point Offset field
is the distance (in mm) between the actual point of camera rotation
and the nodal point. The calculator computes how much two objects
that are at different distances (i.e. one "near" and one "far") from
the camera appear to shift in relation to each other as the camera
is rotated through the specified angle. Put another way, if the two
objects are perfectly aligned (so that the near object appears
directly in front of the far object) before rotation, they will be
seperated by the angular distance determined by the calculator after
rotation. The result is expressed as an angular distance (in
degrees), and the number of pixels. For any given angular shift,
images with larger dimension (i.e. more pixels) and/or smaller
fields of view will show a larger pixel shift. 


This calculator computes the angular field of view for a lens of
a specified focal length on a 35mm camera. For most modern digital
SLR cameras (e.g. Canon D60, Canon 10D, Nikon D100, Fuji S2), a
focal length multiplier of greater than 1 is appropriate because
these cameras have a smaller sensor than a 35mm negative. For these
cameras a focal length multiplier of approximately 1.51.6 is
appropriate. Note: This calculator assumes a standard width/height
image ratio of 3:2. 


This calculator computes the field of view, measured in feet or
meters, for a lens of a specified focal length on a 35mm camera. For
most modern digital SLR cameras (e.g. Canon D60, Canon 10D, Nikon
D100, Fuji S2), a focal length multiplier of greater than 1 is
appropriate because these cameras have a smaller sensor than a 35mm
negative. For these cameras a focal length multiplier of
approximately 1.51.6 is appropriate. Note: This calculator assumes
a standard width/height image ratio of 3:2. 


This calculator computes the number of images and lens focal
lengths required to create a mosaic image covering
the same field of view as a single image. For any given field of
view, overlap percentage, and focal length multiplier (1.6 for most
modern digital SLR cameras) the calculator determines the focal
length of the lens that is needed for each shot in a mosaic
consisting of different numbers of images. 

This calculator computes the equivalent lens focal length and
aperture necessary to produce the same angular field of view and
depth of field on two cameras with different sensor sizes. For
example, a DSLR camera like the Canon 20D (with a sensor size of
22.5x15mm) can be compared to a point and shoot camera like the
Canon A620 (with a sensor size of 7.18x5.32mm). The point and shoot
camera needs a shorter focal length to achieve the same field of
view as the DSLR, and does not need to stop down nearly as much as
the DSLR to achieve the same depth of field. A 50mm lens on the
Canon 20D, stopped down to F11, gives the same angular field of view
and depth of field as the Canon A620 when its lens is set to 16.5 mm
and stopped down to F3.6 

