Ultra-wide capture: fit A3 and bound documents in a single frame

The standard 1× camera on most phones covers approximately 70° of field of view. Paper Scanner’s ultra-wide lens extends this to approximately 120°, allowing full pages to be captured from a normal seated position. Hold the phone 30 cm above an A4 page and the entire page fills the frame; the same distance works for A3 documents, whiteboards, and most bound materials.

Edge detection, perspective correction, and shadow removal run the moment the capture button is pressed, producing a flat page rather than a photograph of paper.

Use cases

Large flat documents. A3 meeting handouts, folded maps, restaurant menus, magazine spreads, and posters. The wider field of view captures the page without requiring the user to stand up or move backwards.

Bound books and manuals. Books with stiff spines typically force the page into a slight curve near the binding, which causes text loss in the inner margin. Holding the phone slightly further away reduces this curve optically before any software correction runs.

Whiteboards and presentation screens. Capture the full board or screen from a seated position in a classroom or meeting room. Perspective correction handles the keystone effect caused by viewing the surface at an angle.

Restricted workspace. When the surrounding area is occupied — coffee cups, hands, other documents — the wider field of view captures the page without needing physical room to step back.

When to use the 1× lens instead

The ultra-wide lens resolves less detail per square centimetre, since the same image sensor is spread across a wider area. Use the standard 1× lens for:

• Dense small text. Contracts, legal documents, footnotes, fine print. Corner sharpness matters more than field of view.
• Glossy media. Laminated IDs, magazine covers, plastic-coated surfaces. The wider aperture gathers more reflection at the edges.
• Low-light conditions. The ultra-wide lens typically has a smaller maximum aperture and produces more noise in dim environments.

The lens toggle is a single tap in the viewfinder.

Shooting best practices

• Even lighting. Indirect light from a window performs better than a single overhead spotlight. Shadows crossing the page are the most common cause of blur and OCR misreads.
• Stable hands. Rest elbows on the table. The shutter waits for a stable frame before firing, so a brief pause typically replaces a re-scan.
• Correct focus. If auto-focus selects the wrong subject (the desk, a finger, the page edge), tap the centre of the text before capture.
• Flat pages. For bound documents, press the page flat with the other hand. Pages that bow toward the spine lose characters near the gutter.

Device requirements

The ultra-wide lens requires iPhone 11 or newer, or a flagship Android device released in the last several years. Devices without an ultra-wide camera fall back to the 1× lens automatically; the rest of the capture pipeline (edge detection, perspective correction, filters) is unaffected.