Digitizing photos is a job you want to do once. The scan you make today is the master your family will still be using in twenty years, so a little extra resolution now is cheap insurance.
The Numbers
Prints
- 300 DPI — the minimum, produces a same-size reproduction. Fine for sharing and viewing.
- 600 DPI — the recommended default. Lets you print at double the original size, and captures enough detail to crop into a photo later.
- 1200 DPI — worthwhile only for very small prints (wallet-size or smaller) that you want to enlarge substantially.
Scanning a print above 600 DPI mostly captures the *paper texture*, not more image detail — the print itself has a finite resolution.
Film Film holds far more detail than any print made from it, and it's physically tiny, so it needs much higher scanning resolution:
- 35 mm negatives and slides: 2400–4000 DPI. At 3200 DPI a 35 mm frame yields roughly 4500 × 3000 px — comparable to a good digital camera.
- Medium format: 1600–2400 DPI is plenty given the larger area.
If you have the negatives, scan those rather than the prints. The difference in quality is dramatic.
File Format and Storage
- Archive master: TIFF (uncompressed or lossless) or a high-quality JPEG at maximum quality. TIFF is the safer long-term choice; JPEG is far smaller and fine if storage is a constraint.
- Never archive only a heavily compressed JPEG. Every future edit and re-save compounds the loss.
- Derivatives: make compressed JPEG or WebP copies for sharing, keeping the master untouched.
- Storage estimate: a 600 DPI TIFF of a 10 × 15 cm print is roughly 50–80 MB. Plan for it, and follow a 3-2-1 backup approach — the point of digitizing is protection against loss.
Practical Scanning Tips
- Clean everything: the glass, and the photos. Dust shows as white specks that take longer to retouch than cleaning takes.
- Scan several photos at once and let the software split them, or crop later — batch scanning is what makes a large album feasible.
- Turn off auto-correction for the master scan. Automatic colour and contrast fixes are irreversible; do adjustments on a copy.
- Use infrared dust removal if your scanner supports it for film. Note it doesn't work on traditional black-and-white silver film.
- Scan straight — align the photo to the platen edge; rotating later costs a resampling pass.
- Capture the back if it has handwriting, dates or names. That metadata is often more valuable than the image.
Alternatives to a Flatbed
- Phone scanning apps are surprisingly good for casual digitization and handle perspective correction automatically. Quality is well below a flatbed but the speed means you'll actually finish.
- Camera copying — a camera on a tripod with even light gives excellent results for prints and is far faster than a flatbed.
- Professional services are worth it for large collections, fragile items, or film formats you can't scan yourself.
Whatever the method, record the year and people while someone still remembers — an unlabelled scan is a much smaller gift than a labelled one.