Image from my camera is flickering

This issue can arise because fluorescent and LED lighting actually flashes very quickly, at a rate dependent on the electrical power frequency. This rate is fast enough that it is imperceptible to human vision. If the camera's frame rate is mismatched with the flicker rate of the lighting, the camera may acquire images at points of high and low brightness, resulting in a flicking image. For example, common power sources are 50 Hz (in Europe and most of Asia) and 60 Hz (in North America), which cause 100 and 120 pulses of light each second, respectively.

Solution: Alter the frame rate of the camera in your Noldus software 

Under normal lighting conditions in North America, a frame rate of 25 will occasionally result in a flickering image and it can be resolved by increasing the frame rate to 30.  However, you may need to alter the frame rate and check to see the resulting image no longer flickers. This is especially true for dimmable lighting as altering the dim settings will alter the pulses of light each second (e.g., more dim = fewer pulses).

EthoVision XT

In the Experiment Settings, alter the frame rate for your camera(s) and click on theicon to get a live image to see if the issue is resolved.  


 If not, you can alter the frame rate and view the resulting image in the Video Settings window that opens after clicking the icon.


NOTE The image will take a few seconds to update after making any changes.

Also, these settings will become locked once you have acquired any trials in your experiment. If those trials are not needed (e.g., they were just tests to make sure the settings were ok), you can delete them. Otherwise, you can create a new experiment. To create a new experiment but copy all the settings (but not data) from the original experiment, pick the option to create a New Template Experiment, then Custom Template, and pick your existing experiment as the source. Note this can take a while, especially if the original experiment contained many trials.


In the Video Settings, alter the frame rate for your camera(s) under the Frame rate column and click Apply to see if the issue is resolved in your live image in MediaRecorder.  If not, repeat the procedure until the flickering no longer appears. 

 NOTE The image will take a few seconds to update after making any changes.