Use a reference that exposes the edges
Apple TV’s Calibration tools include Zoom and Overscan, a reference image for adjusting the television’s picture fitting. It helps answer a specific question: can the screen show the complete output without hiding its margins?
Begin there when system labels or picture edges are cut off. A wide film with intentional bars is a different observation and should not automatically trigger a global zoom change.
Adjust the television deliberately
Open Settings, Video and Audio, Calibration and select the reference. Use the television’s documented zoom or overscan controls while the image remains visible. Names and availability depend on the TV model and input.
Inspect all four edges after a small change. The aim is a complete, correctly shaped picture. Filling the panel by cutting off the reference does not solve edge loss.
Keep other scaling layers stable
Leave accessibility Zoom and any app-specific crop choice unchanged during the TV comparison. These layers serve different purposes and can make a working adjustment difficult to identify when changed together.
After the reference fits, check ordinary menus and a familiar programme. If only one app still crops content, investigate that app’s actual picture controls separately.
Use the correct AirPlay control when relevant
Apple also documents a specific AirPlay Display Underscan setting for AirPlay pictures. That source-specific control is not a replacement for checking ordinary Apple TV output with the calibration reference.
Record the TV input and fitting choice that worked. This page describes Apple’s reference procedure and does not claim professional geometric calibration or improved source resolution.
Questions answered
Will the reference remove legitimate film bars?
Its purpose is to check complete output edges, not force every source to fill the panel.
Is accessibility Zoom the same as TV overscan?
No. They operate at different layers and should be checked separately.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.