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DepthCalc

Introduction

DepthCalc is a depth of field (DOF) calculator for Windows Mobile devices, such as PDA's and SmartPhones. DepthCalc allows you enter a focal length and subject distance, as well as select a range of apertures. It will then display a DOF table showing the near and far DOF limits and hyper-focal distance for each selected aperture.

DepthCalc should work on any Windows Mobile device running version 5 or later of the Windows Mobile OS. Users of Windows Mobile 5 devices will need to install the .NET 2.0 Runtime first; Windows Mobile 6 already has the .NET 2.0 Runtime pre-installed.

Installation is simple enough. Just copy the installation CAB file to a folder on your device, and then run it. You'll get a prompt warning you that the package is signed by an unknown publisher (because I used a personal certificate for digital signing), just click 'yes' to continue.

Running DepthCalc

Once the program is installed you should have a shortcut in your programs folder/menu. Launching the program will present you with the main screen, which allows you enter the parameters that will be used to calculate the DOF table:

The following parameters can be specified:

  • Focal Length - focal length in millimeters that the DOF data should be calculated for.
  • Distance - distance in feet that the lens is focused to
  • CoC - The circle of confusion value to use for calculating DOF. Commonly-used values are .02mm for DX cameras and .03mm for full-frame/35mm cameras. I prefer to use a smaller CoC to give me more pessimistic DOF numbers that can be used for larger prints.
  • F/Stop Intervals - whether the DOF table will only show full-stop apertures, or also include half-stop or third-stop apertures.
  • Start and End F/Stop - these let you limit the range of apertures displayed in the DOF table so that you don't have to see information about apertures you don't care about.

Your selections for these parameters will be saved and used as defaults the next time you run the program, so it will always display your last-used settings on start-up.

The main screen also has two soft-button commands. 'Calculate' will calculate the DOF information for the current settings and display the results. The 'File' menu contains an 'Exit' command that will close the application and unload it from memory (unlike the normal close/OK command that just hides the application and keeps it running in the background). The 'File' menu also allows you to choose between using feet or meters for distances.

Navigation

DepthCalc was designed so that it is possible to navigate and select options using only the directional arrow keys. This is an advantage for users of PDA-style devices who do not wish to have to open a flip-out keypad to enter alpha-numeric data. DepthCalc supports the following navigation/data-entry shortcuts:

  • Up Arrow - move focus to the previous control on the screen.
  • Down Arrow - move focus to the next control on the screen.
  • Left Arrow - For textboxes, this key will decrease the value for that textbox. For combos, it will select the previous item in the list
  • Right Arrow - For textboxes, this key will increase the current value for that textbox. For combos, it will select the next item in the list

In addition to these shortcuts, DepthCalc also supports standard navigation (for instance, with a stylus or the tab key), as well as data entry with a keyboard/keypad.

Results Display

Once you enter the desired parameters and press the 'Calculate'  soft-button, a results screen will be displayed with the requested DOF information:

The top line shows the focal length and focus distance that the DOF table was calculated for. Below that is a table containing a row for each f/stop in the specified aperture range. The table shows near and far limits of the DOF, as well as the hyper-focal distance. All distances are in feet.

You can use the up/down arrows to scroll though the list, making it easier to read the row of data you're interested in. Once finished viewing the results you can hit the OK button or the 'Done' soft-button to return to the main screen.

License Agreement

DepthCalc is Copyright (c) 2008 Jeff Kohn. All Rights Reserved.

This software is free for personal use. If you are so inclined
you can send a small PayPal donation to jsk@kohn-family.com.

This software may not be modified or repackaged for sale without
written permission from the author.

This software is provided "as is", with absolutely no warranty
expressed or implied. Any use is at your own risk. In no event
shall the author be held liable for any direct, indirect,
incidental, special or consequential damages arising out of
the use of or inability to use this software.