How to Change the Frame Rate in Logger Pro

Changing the frame rate in Logger Pro allows you to precisely control the time base for video analysis, ensuring your data reflects your experimental conditions accurately. For Logger Pro versions 3.8.2 and newer, you can easily override the marked frame rate of any movie to your desired value.

Step-by-Step Guide to Adjusting Frame Rate

Follow these simple steps to modify the frame rate for your video analysis in Logger Pro:

Open Your Project: Launch Logger Pro and open the experiment file containing your movie, or import a new movie for analysis.
Select the Movie: Ensure the movie window is selected. You can do this by clicking directly on the video pane within Logger Pro. This makes the movie the active element for options.
Access Movie Options: Navigate to the Options menu at the top of the Logger Pro interface. From the dropdown, select Movie Options. This will open a dialog box with various settings related to your video.
Override Frame Rate: Within the Movie Options dialog, locate the section related to frame rate. You will see a checkbox labeled something similar to "Override Frame Rate" or "Use Specified Frame Rate." Check this box.
Enter Desired Frame Rate: Once the override option is checked, a field will become active where you can input your desired frame rate (in frames per second, or fps). Enter the exact value you wish to use for your analysis.
Apply Changes: Click "OK" or "Apply" to save your new frame rate setting. Logger Pro will now use this specified frame rate for all subsequent analysis of that movie.

Why Override the Frame Rate?

Overriding the frame rate is particularly useful in several scenarios:

Correcting Mismatches: Sometimes, a video's metadata might incorrectly report its frame rate, or the capture device might have recorded at a slightly different rate than intended. Manually setting it ensures accuracy.
Synchronizing with Data: If you are collecting sensor data simultaneously with video, ensuring the video's frame rate matches your data collection rate can simplify synchronization and analysis.
Specific Experimental Conditions: In physics or other scientific experiments, you might need to analyze motion at a very specific temporal resolution that doesn't match the original video's inherent frame rate.
Slow-Motion Analysis: For precise analysis of rapid events, even if the video wasn't explicitly shot in slow motion, you can define a custom, often lower, effective frame rate for more detailed point-by-point tracking.

Practical Insights

Version Compatibility: This feature is available in Logger Pro 3.8.2 and newer versions. If you are using an older version, consider updating your software for enhanced video analysis capabilities. You can check your Logger Pro version by going to Help > About Logger Pro.
Impact on Analysis: Changing the frame rate directly affects the time scale in your video analysis graphs and tables. Ensure your chosen rate is appropriate for the phenomena you are studying.
Reversibility: You can always go back into Movie Options and uncheck the "Override Frame Rate" box to revert to the movie's original detected frame rate, or specify a different one.

For more detailed information on video analysis and Logger Pro features, refer to the official Vernier Software & Technology website.