Ultra-wide rear camera selection
Automatic camera selection for the focal length you choose.
Where to find it
Viewfinder Focal Length slider
Summary
The app automatically selects the best rear camera (standard or ultra-wide) based on the focal length slider. Uses selectBestCameraForFocalLength to pick the camera with the closest field of view.
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How it works
What it does
As you slide the focal length control, the app switches between the phone's rear cameras (usually standard and ultra-wide) to match the focal length you selected. If you set the slider to 35mm and the phone has an ultra-wide camera, the app might switch to ultra-wide to get closer to 35mm. Set it to 50mm and it might switch back to the standard lens.
Why it matters
Different cameras see different angles. The standard rear camera is typically 50mm-ish; the ultra-wide is typically 20mm-ish. By switching cameras the app gives you a preview and reading that more closely matches the focal length you intend to shoot with.
Manual override
The camera selection is automatic and happens in the background. If you want to force a specific camera you can tap the camera selector (if the UI includes one) to lock to a single lens.
Limits
The app can only choose from cameras the phone has. If you set the slider to 28mm but the phone only has a 50mm standard and a 13mm ultra-wide, the app picks the closest (ultra-wide) or asks you to pick one. Very old or low-end phones may have only a single rear camera, in which case no switching happens.