thanks @rob

After repeating the experiments several times, I found that the accuracy loss caused by transferring a calibration between recordings is actually acceptable. The more significant issue is the gaze estimation error introduced by the mismatch between the calibration distance and the actual viewing distance, which can vary considerably during use.

To clarify my workflow, the custom images I mentioned are simply images similar to the example shown below, with the markers placed at different positions. I do not perform calibration during recording. Instead, after recording, I use the marker detection feature in Pupil Player together with Post-hoc Calibration to generate the calibration.

Regarding your second point, I have not yet come up with a suitable approach for multi-distance calibration. My intuition is that allowing the participant to move during the calibration process would likely introduce a substantial loss in calibration accuracy, although I have not tested this systematically yet.

Hi @user-7c9706 , would it be possible to share one of the recordings with [email removed] Even a test session where you run it on yourself would be helpful, so that we can see exactly how it is being done and what the issue might be.