How to get rid of shadows on scanned documents

The most common blemish on phone scans is a soft grey diagonal — the shadow of the phone or your arm. It's also the most preventable, and what slips through is exactly what the enhancement step is best at removing.

Know your shadows

• The phone's own shadow: light from behind you, phone above page → a phone-shaped patch dead centre.
• Hand/arm shadow: side light crossing your reaching arm.
• Fold shadows: creases lift the paper into tiny ridges that cast lines.
• Object shadows: the coffee cup just outside the frame, casting inside it.

Prevention beats processing

1. Face the light: position yourself so light comes from your front-left or front-right, never directly behind.
2. Lower the phone slightly and step off-axis — the phone's shadow moves off the page while the camera stays square enough.
3. Press folds flat for ten seconds; align remaining creases along the light, not across it.

What the software removes

ToPDF's enhancement estimates the page's illumination and flattens it — soft gradient shadows and vignettes lift away, paper becomes uniformly bright, text keeps its weight. Try a deliberately half-shadowed page and watch it even out. Hard shadow edges (sharp dark boundaries from direct sun) leave a faint trace even after correction — those are the ones worth re-shooting.

Frequently asked questions

Why do my scans have a dark stripe on one side?

Classic single-ceiling-light setup: the page sits half in your body’s shadow. Rotate the whole arrangement 90° so the light path clears you.

Can I scan under a desk lamp at night?

Yes — bounce it: aim the lamp at a white wall or ceiling above the document instead of straight down. Soft reflected light, no hotspot. More in the low-light guide.