Telemetry, control rails and the Assist Line

The telemetry row across the top of the Pro screen shows the camera's current ISO, shutter (S), aperture (ƒ), white balance (WB) and tint. Each value is also the button that opens its control rail on the right edge of the screen.

Open and adjust a value

1. Tap a value, such as S.
2. Drag the rail's scale to change the value. On ISO, S and ƒ the drag also fixes the value, and the padlock closes by itself; tap the padlock to hold the current value or return it to automatic. WB and TINT use the AWB / MWB button instead: White balance.
3. Tap another value to switch rails. Only one of ISO, S, ƒ, WB and TINT is open at a time.

Expected result: the chip takes a gold outline and marker (1), and its rail (2) replaces the zoom rail.

Bring the zoom rail back

Closing a rail by tapping its value returns the right edge to the zoom rail. After a swipe, the edge stays clear so you can see the whole frame. To bring zoom back, tap the right edge of the screen or swipe left from it.

Close the rail

Tap the selected value again, or swipe the rail toward the right edge of the screen. A short sideways swipe is enough; an up or down drag on the rail changes the value instead. Tapping another value closes this rail and opens that one.

Expected result: the rail slides off and the value loses its gold outline. Rails do not close by themselves; an idle rail only dims slightly.

Tapping the preview does not close a rail on iPhone: it focuses on the point you tap. On iPad, a tap outside an open rail closes it.

The Assist Line (1) shows confirmations, warnings and why an action is refused; otherwise it is empty.

A message replaces any of the same or a lower level; lower-level messages are not queued. After a take, tap the summary on the line to open the Take Receipt. When the camera records something other than your setting, the line names it: tap the line for the full list, Recording with changes (+N counts the others).