Backdrops

What it does

Any still from your library can sit behind the whole programme instead of a flat brand colour.

You do not set the dimming. The renderer measures the image where the text will actually land and darkens it until the contrast is enough to read.

The standard behind it

• Dimming is measured against the region the captions occupy, not the whole frame. A photograph that is bright in one corner and dark elsewhere would otherwise be dimmed to almost nothing to protect a region the text never touches.
• The image is never washed out completely and never left undimmed. Both ends are bounded, because "legible" stops meaning anything if the picture is gone.