In Beam Studio, click on the camera icon () at the bottom left and select your machine from the list. The preview mode is ready when the mouse cursor becomes a camera (). Click and drag your mouse cursor to preview the work area. Click on again or press ESC to leave preview mode.
If the preview result is not accurate, click menu > Machine > choose Machine > Calibrate Camera to run camera calibration. Compare the red-dotted-line square with the actual square engraved, manually adjust values to overlap the 2 squares.