Photography Calculators


Version 7 : March 16, 2008


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.    
© Max Lyons, 2003-2007
Tawbaware | Max Lyons Image Gallery
Original Calculator


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 left-click on the bookmark link to reload the page, or right-click to open a new window, copy the link location to the clipboard, or perform other operations in your browser.]


Additions © Alan Fletcher, 2007
FARFOTO



Alan's DOF Comparator Max's DOF Calculator Max's Parallax Calculator
Max's Angular Field of View Calculator Max's Dimensional Field of View Calculator Max's Mosaic Calculator
Max's Lens Equivalence Calculator

Alan's Depth of Field Comparator

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.

Distance Units:
 
   For these values the FL Multiplier only affects the CofC
Distance to subject: Near focus distance and DOF:
Lens focal length (mm): Bookmark Far focus distance and DOF:
Aperture:   Total Depth of field:  
Circle of confusion (mm):   Depth of focus:
Focal length Multiplier:   Hyperfocal distance:
Diffraction Threshold: Pixels
CofC
  Airy Disk Diameter mm (um):
Diffraction Wavelength: Red: 630, Green: 550, Blue: 480

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For the following table the specified Focal Length is Converted from:


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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 In-focus 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.

Max's Depth of Field Calculator

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, point-n-shoot 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.
Distance Units:
 
Distance to subject: Near focus distance:
Lens focal length (mm):   Far focus distance:
Aperture:   Depth of field:
Circle of confusion (mm):   Depth of focus:
      Hyperfocal distance:
      Airy Disk Diameter (mm):

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Max's Parallax Calculator

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.
Distance Units:
 
Nodal Point Offset (mm): Angular parallax error (degrees):
Distance to near object:   Pixel shift parallax error (pixels):
Distance to far object:    
Camera rotation angle (degrees):    
Image Field of View (degrees):    
Image Width (pixels):    

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Max's Angular Field of View Calculator

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 1.5-1.6 is appropriate. Note: This calculator assumes a standard width/height image ratio of 3:2.
Lens focal length (mm): FOV (horizontal) (degrees):
Focal length multiplier:   FOV (vertical) (degrees):
      FOV (diagonal) (degrees):

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Max's Dimensional Field of View Calculator

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 1.5-1.6 is appropriate. Note: This calculator assumes a standard width/height image ratio of 3:2.
Distance Units:
 
Lens focal length (mm): FOV (horizontal) (feet/meters):
Focal length multiplier:   FOV (vertical) (feet/meters):
Distance to Subject:   FOV (diagonal) (feet/meters):

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Max's Mosaic Calculator

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.
Horizontal field of view (degrees): 1x1 mosaic focal length (mm):
Overlap percent (%):   2x2 mosaic focal length (mm):
Focal length multiplier:   3x3 mosaic focal length (mm):
      4x4 mosaic focal length (mm):
      5x5 mosaic focal length (mm):
      6x6 mosaic focal length (mm):

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Max's Lens Equivalence Calculator

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
Camera 1 Sensor dimensions (mm): x Camera 2 Focal Length (mm):
Camera 1 Focal Length (mm):   Camera 2 Aperture:
Camera 1 Aperture:  
Camera 2 Sensor dimensions (mm): x  

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