What is the difference between scanning a document and just taking a photo of it?
A photo records the page as it appeared from where you stood — tilted, with the desk in the background and your shadow across it. A scan detects the page edges, crops away everything else, warps the page back into a true rectangle, evens out the exposure, and writes it as a PDF page. PDF Scanner does all of that in one capture, which is why a scanned page is accepted by forms and offices that reject camera photos.
The short version
- A scan crops to the detected page edges; a photo keeps the desk, hands and background in frame.
- Perspective correction warps a page shot at an angle back into a true rectangle; a photo stays skewed.
- Brightness and contrast adjustment evens out uneven lighting so faint print stays legible.
- PDF Scanner exports multi-page documents as a single PDF, while photos stay as separate image files.
- PDF is the format most forms, employers and government offices ask for; a camera roll photo often is not accepted.
- PDF Scanner also exports JPG when an upload form specifically asks for an image.
- Capture, cropping and OCR run on the iPhone using Apple's built-in frameworks, so documents are not uploaded to a server.
Step by step
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Decide what the recipient needs
If a form, employer or office is receiving it, they almost certainly want a PDF. If you are texting a page to a friend, a photo or a JPG is fine.
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Capture with edge detection rather than the camera app
Point the scanner at the page on a contrasting surface and let it find the outline. This is what removes the background instead of you cropping by hand afterwards.
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Check the crop and straighten
Confirm the detected outline sat on the page and not on a shadow or a table edge, then use perspective fix so the page is square rather than trapezoidal.
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Even out the exposure
Brightness and contrast is what makes a scan look like a scan — consistent white paper instead of one bright corner and one grey one.
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Export as PDF
Multiple pages captured into one document export as a single PDF in order, which is the practical difference from ending up with five photos in a camera roll.
Frequently asked
- Will anyone actually reject a photo of a document?
- It happens regularly with applications, HR paperwork and government forms — often because the upload only accepts PDF, and often because a skewed, shadowed photo is hard to read. A scan avoids both objections.
- Is a scan higher resolution than a photo?
- It comes from the same camera, so the raw detail is comparable. What changes is that the frame is filled with the page instead of the surrounding desk, so more of that resolution is spent on the document itself.
- Can I convert photos I already took into a PDF?
- A photo already taken is missing the edge detection step, so you would be cropping and straightening manually. Rescanning the page usually takes less time and gives a much better result.
- When is a plain photo the better choice?
- When the content is not a document — a whiteboard sketch you just want to remember, a product label, a page you are reading. Scanning is worth the extra moment when the page will be sent, filed or printed.
- Does scanning upload my document?
- Not with PDF Scanner. Capture, correction and text recognition happen on the iPhone using Apple's built-in frameworks, and document images are not sent to a server.
Last updated 2026-07-28