Knowledge Base

Problem

Researchers setting up a Novel Object Recognition task with mice in EthoVision XT are unsure of the optimal Basler RGB camera exposure, frame rate, and detection settings for reliable tracking.

Details

Users new to EthoVision or switching camera hardware ask about best-practice acquisition settings for top-down open-field-style tasks such as NOR. Relevant for EthoVision XT 17, 18, and 19 with Basler GigE color cameras. Common concerns include motion blur, flicker from artificial lighting, and detection contrast.

Solution

1. Start with default camera settings in EthoVision; avoid unnecessary adjustments until a specific problem is identified.
2. Set exposure time to approximately 1/100 to 1/120 second to reduce motion blur while maintaining adequate brightness under standard lab lighting.
3. Use a frame rate of 25–30 fps, which is sufficient for mouse locomotion tracking in NOR.
4. Ensure uniform, shadow-free illumination over the arena; avoid direct overhead lights that create bright spots or reflections on the floor.
5. For detection, use the grayscale or luminance channel if animals have good contrast against the arena floor; use color-based detection only if animals are marked or have a distinctive color.
6. Set subject size (minimum and maximum pixels) to tightly bracket the expected mouse size so that objects and shadows are not mistakenly detected.
7. Grab the background reference image with no animals in the arena and with all lights on at acquisition intensity.
8. If recording for later offline analysis, use EthoVision's built-in video recording or MediaRecorder; verify that the recorded file plays back correctly before starting the experiment series.