How to Record Mouse Open Field Videos for Automated Tracking

1. Use a fixed camera

Keep the camera stationary for the entire recording.

Camera movement changes the apparent position of the arena and can be mistaken for movement within the experiment.

For standard Open Field tracking, an overhead view is usually the clearest way to preserve the geometry of the arena.

Checklist

• mount the camera securely
• avoid handheld recording
• avoid zoom changes during the session
• do not reposition the camera after calibration begins

2. Keep the full arena visible

The relevant experimental arena should remain visible throughout the analyzed interval.

RodentMetrics uses the arena definition during configuration, so boundaries should be clear enough to identify consistently.

Avoid

• cropping arena edges
• equipment blocking important boundaries
• the camera shifting so the arena leaves the frame

3. Maintain stable lighting

Large changes in illumination can make an animal appear different across frames and can introduce shadows or reflections that interfere with tracking.

Use lighting that is consistent with the scientific requirements of the experiment while keeping the recorded image visually stable.

The goal is not maximum brightness. The goal is consistent, usable contrast.

4. Preserve mouse-to-background contrast

Tracking becomes easier when the mouse can be visually distinguished from the arena floor.

Before collecting a full experiment, record a short test clip and confirm that the animal remains visually distinct across different parts of the arena.

Watch for

• low contrast
• reflections
• strong shadows
• patterned surfaces
• bedding or objects similar in appearance to the animal

Do not prescribe a specific arena color because appropriate conditions vary by animal and experiment.

5. Minimize unrelated movement

The current RodentMetrics Mouse Open Field workflow is designed around one mouse as the primary moving subject.

Where possible, avoid unrelated moving objects in the frame.

Examples include:

• investigator hands
• moving cables
• other animals
• shifting equipment
• moving reflections or shadows

The researcher should leave the recorded area after placing the animal when that is compatible with the study protocol.

6. Keep camera and arena geometry consistent

Physical measurements depend on the relationship between image coordinates and the experimental arena.

Once a recording setup has been established, keeping the camera position, zoom and arena position consistent reduces avoidable variation between recordings.

If the camera or arena geometry changes substantially, configure the relevant recording using its actual setup rather than assuming the previous geometry still applies.

7. Check the recording before running a full study

A short pilot recording can identify tracking problems before a large dataset has been collected.

Before recording an entire experiment series, review a sample clip for:

• arena visibility
• stable camera position
• lighting consistency
• mouse/background contrast
• reflections or shadows
• unrelated movement

View workflow video

Before you upload: quick checklist

• Camera is fixed
• Arena remains visible
• Lighting is consistent
• Mouse is distinguishable from the background
• Unrelated motion is minimized
• Recording contains the interval intended for analysis
• Arena dimensions are known if physical distance/speed units are required

What happens after recording?