The iOS ecosystem trap: HEIC leaves the phone, compatibility stays behind
iPhone cameras default to HEIC to save storage. That works inside Apple Photos — until you AirDrop, email, or sync to Windows. Recipients see blank thumbnails or “cannot open this file.” Converting Apple image to PDF (or iOS photo to PDF) solves the handoff: one document that opens in Edge, Chrome, Acrobat, and school portals. This page is strictly about that Apple-to-everywhere friction — not generic batching or print-shop sizing.