focusinspector

Simple utility for DSLR photographers. It allows you to overlay the used focus points over the image. It can also be used to fine tune your lens focus.

Installation

Before you install this software, make sure you have the following dependencies installed:

All these package can be found on the commonly used Linux distros. You can easily install them with the package manager.

Additionally, you need to have the following ruby gem packages installed:

These will be automatically installed when you install Focus Inspector as a gem package.

gem install focusinspector

Usage

Focus Inspector has 3 usage modes:

Show focus grid and active focus points

Display a JPG or raw file with focus grid overlay. The file needs to have proper EXIF information.

focusinspector show DSC_1234.NEF

If you don’t have KDE installed, you need to use the –viewer option to specify the JPG viewer to be used.

Measure sharpness of the image of the FI test chart

This only works with an photograph of the Focus Inspector test chart. The test pattern must be surrounding the active focus point and should roughly cover a quarter of the total image.

focusinspector measure DSC_1234.NEF

The result is a sharpness value in percent. This is not really an absolute value, but it can be used to compare sharpness of images that were taken under the same lighting conditions with the same test chart.

List some focusing relevant EXIF data

Just for convenience.

focusinspector list DSC_1234.NEF

Supported Cameras

Currently, only the following cameras are supported:

Adding other cameras is fairly straight forward. The location of all focus points needs to be added to lib/focusinspector/Camera.rb. Unfortunately, not all EXIF tags are standardized across camera vendors. Adding support for other vendors than Nikon might require some additional work to find and parse the right EXIF tags.

Contributing to focusinspector

Copyright and lincense

Copyright © 2012 Chris Schlaeger. See LICENSE.txt for further details.