How to scan and restore old photos

Somewhere in your house there is a box of photographs that exist in exactly one copy. This post is about getting them into a form that survives, which is a different job from making them look nice. Do the capture properly first, keep an untouched master, and then restore. Do it in the other order and you will be scanning everything twice.

The single most common mistake is picking a scan resolution because someone on a forum said 600. The right number depends entirely on what you plan to do with the file, and for a small original it can be much higher than 600.

Decide the output first, then work backwards to the resolution

There is no universally correct scan DPI. There is only the resolution that gives you enough pixels for the largest output you might ever want. So start at the end.

The arithmetic is one line:

scan DPI = (output width in inches x output PPI) / original width in inches

Say you have a 4 x 6 inch print and you might one day want an 8 x 12 inch print at 300 PPI. That needs 3600 pixels across. The original is 6 inches wide, so 3600 / 6 = 600 DPI. If instead you have a 2 x 3 inch wallet photo and want that same 8 x 12, you need 3600 pixels from 3 inches of original, which is 1200 DPI.

Same target, same quality, double the number, because the original is half the size. That is the whole principle: small originals you intend to enlarge need high scan resolutions, and large originals rarely do.

For screens, the numbers collapse. A 4K display is 3840 pixels wide. Almost any print scanned at 600 DPI already exceeds what any monitor can show. Resolution planning is really print planning.

Why 300 PPI is the print baseline, and when it is the wrong baseline

300 PPI became the standard because it sits comfortably past what most people can resolve at normal reading distance, and because commercial print workflows settled on it decades ago. Photo labs generally treat 300 PPI as the target and many accept 240 PPI without visible loss.

It is a viewing-distance rule dressed up as a technical rule. A poster seen from two meters away looks fine at 150 PPI. A gallery print someone will lean into wants 300 or better. Billboards are printed at resolutions that would look like mush on a desk.

Go above 300 PPI in three cases: the original is small and you plan to enlarge it, the original has fine detail worth resolving (a group photo where you want faces readable, or handwriting on the back), or the print is damaged and you want restoration headroom, because retouching is easier when you have pixels to spare and can downsample afterwards.

If the DPI-versus-PPI distinction is still fuzzy, our post on DPI and resolution for web versus print takes it apart properly.

Flatbed scanner or phone camera

Both work. They fail differently.

A flatbed scanner gives you even illumination across the whole frame, no perspective distortion, no camera shake, and a known, repeatable resolution. It is slower, it is another device to own, and cheap models struggle with anything that is not flat.

A phone camera is faster by a large margin, handles curled prints and photos still glued into albums, and is with you when you are visiting a relative who will not let the album leave the house. The problems are glare, uneven light, and keeping the sensor plane parallel to the print.

If you photograph prints, the things that actually matter:

• Light from two sides at roughly 45 degrees, or one large diffuse source such as a north-facing window. Overhead light directly above a glossy print puts a hotspot in the middle of it.
• Shoot straight down and parallel. Any tilt shows up as a trapezoid, and correcting it in software throws away resolution.
• Use the main 1x lens, not the ultrawide. Ultrawide lenses bend straight edges, which is exactly what you do not want on a rectangular print.
• Do not pinch to zoom. That is digital cropping. Move the phone closer.
• Turn the flash off. On-camera flash on a glossy print produces a mirror of the flash.
• Shoot RAW if your phone offers it, and use a timer or a remote so pressing the shutter does not nudge the frame.

Multi-shot apps such as Google PhotoScan work by taking several frames from slightly different positions and combining them to remove glare. They are a reasonable answer for glossy prints when a scanner is not available, though the output resolution is fixed by the phone sensor and the framing rather than chosen by you.

Dust, glare and Newton rings

Dust is the tax on scanning. A speck on the scanner glass appears on every single image in the batch, in the same place, which at least makes it easy to spot afterwards.

Before you start: clean the glass with a lint-free cloth, and clean the prints with a soft brush or an air blower bulb. Not canned air, which can spit propellant. Not water, not cleaning fluid, not a fingernail. Old emulsions are more fragile than they look, and surface damage cannot be undone.

If prints are stuck together or stuck to album plastic, stop. Forcing them tears the emulsion off. That is a conservator's job, and it is recoverable right up until the moment you pull.

Newton rings are the rainbow or oil-slick concentric patterns you sometimes get when two smooth surfaces are almost, but not quite, touching. They are an interference effect, not dirt, and no amount of cleaning removes them. They show up most with glossy prints and with film pressed flat against scanner glass.

Fixes, in order of preference: use the film holders that came with the scanner so the film sits slightly above the glass; use anti-Newton glass if you have it; for a glossy print, lift it a fraction of a millimeter off the platen or rotate it a few degrees and rescan. Rotating often breaks up the pattern enough to clear it, and a small rotation is trivially corrected later.

Prints, negatives and slides are three different jobs

Scanning a print means scanning a copy. Whatever the lab did when it made that print, good or bad, exposure, colour cast, crop, is baked in. You are capturing the artifact as it exists.

Scanning a negative or slide means going back to the original capture, which usually holds noticeably more detail and dynamic range than the print made from it. If you have the film, scan the film. It needs a scanner with a transparency unit, meaning a light source in the lid, because film has to be lit from behind. A flatbed without one physically cannot do it.

Film is also physically small, so the resolution rules above bite hard. A 35mm frame is roughly 36 x 24 mm, about 1.4 x 0.9 inches. Scanning it at 300 DPI gives you a postage stamp. 2400 to 4000 DPI is the normal working range, and that is where flatbed marketing claims get slippery: check the optical resolution, not the interpolated number on the box. Interpolated resolution is software inventing pixels between real ones, and it adds file size rather than detail.

Color negatives carry an orange mask that has to be inverted and corrected. Scanner software does this automatically, and the automatic result is a starting point rather than an answer. Slides are easier: what you see is what was there.

Settings that matter, and settings to leave off

• Color mode: scan in colour even for black-and-white prints. Old prints have sepia, silvering and paper tone that grayscale mode discards, and you can always convert later.
• Bit depth: use 16-bit per channel if offered, particularly for faded or high-contrast originals. More tonal headroom means fewer banding artifacts when you pull the contrast back.
• Auto-correct, auto-colour, auto-contrast, sharpening, backlight correction: off. Every one of these bakes an irreversible decision into your master. Restoration is easier from a flat, honest, slightly dull scan.
• Descreening: on only when scanning something printed with halftone dots, such as a newspaper or magazine page. A photographic print is continuous tone and does not need it, and descreening softens real detail.
• Format: TIFF or PNG for the master. Both are lossless. JPEG throws away data at save time, and repeated saves compound it.
• Scan the whole print, including a sliver of the border. You can crop later; you cannot uncrop.

Save an unmodified master before you touch anything

This is the rule that matters more than any other in this post.

The moment a scan finishes, save it, name it, back it up, and then never edit that file again. Every restoration you do happens on a copy. Software improves, your skills improve, and you will want to redo work you did in 2026 with better tools in 2032. If you retouched the master in place, you are back at the box of prints, assuming the box still exists.

A workable convention:

• 1975-08_grandparents-beach_master.tif for the untouched scan.
• 1975-08_grandparents-beach_v1.jpg for the restored version you actually share.
• Dates first so files sort chronologically. Approximate dates are fine; write 1975c or 1970s rather than nothing.

Put what you know into the file itself as well: names, place, date, and who told you. IPTC and EXIF description fields travel with the image and survive being copied between drives, which sticky notes and your memory do not. You can check what a file is actually carrying with the image metadata viewer, which reads the file locally in your browser rather than uploading it anywhere.

Then back up on the 3-2-1 principle: three copies, on two different kinds of media, one of them off-site. A single external drive holding the only copy of a family archive is a slow-motion accident.

A sane restoration order

Work in this sequence on a copy, and save incremental versions as you go:

1. Straighten and crop to the image area, leaving the master untouched.
2. Dust and scratches. Spot removal at 100% zoom, working systematically across the frame rather than hunting.
3. Tears, missing corners, creases. Clone or heal from nearby matching texture. Big losses are reconstruction, which is a judgment call about how much invention is acceptable.
4. Tone. Set black and white points, then adjust midtones. Faded prints have almost no true black in them and often come alive with nothing more than this.
5. Color. Correct the cast. Color prints from the 1970s and 1980s commonly shift toward orange or magenta as dyes fade at different rates.
6. Sharpening last, and gently, sized for the output. Sharpening early amplifies every scratch you are about to remove.
7. Enlarge, if needed, after the cleanup rather than before.

Save the shareable version as JPEG at high quality, and keep the layered or lossless working file if your editor produces one.

What upscaling and restoration honestly can and cannot do

Upscaling tools, including the browser-based image upscaler here, are useful and also widely misunderstood. Be clear about the mechanism: an upscaler increases pixel dimensions and reconstructs what plausibly belongs in the new pixels. Modern ones do this far better than the old bicubic interpolation, which just produced a larger, blurrier image. But reconstruction is not recovery.

What upscaling genuinely helps with:

• A small scan that needs to be a bit larger for print, where the detail is present but the pixel count is short.
• Slightly soft edges, textures and film grain, which tend to be cleaned up convincingly.
• Getting an old low-resolution digital photo, from a 2004 compact camera or a phone, to a size that does not look ragged on a modern screen.

What it cannot do, regardless of what any product claims:

• Recover detail that was never recorded. If the negative was out of focus or the print was a soft 3x enlargement, that information does not exist in the file. Nothing can read it back.
• Guarantee that a reconstructed face is the right face. Face-enhancing models are trained on faces in general, and they can subtly change features, ages and expressions. On a photo of a stranger, nobody notices. On a photo of your grandmother, the family will.
• Undo physical damage without inventing content. Where the emulsion is gone, whatever appears there is a guess, whether made by you with a clone tool or by a model.

Before you enlarge, ask whether you need to. If the file is destined for a screen, a phone, a shared album or a message, a 2400 x 3600 pixel scan is already far more than any display will show. Upscaling it accomplishes nothing except a bigger file. The place upscaling earns its keep is print, and only when the arithmetic at the top of this post says you are short.

Working through a whole box without losing a weekend

Two habits make the difference between a project you finish and one that stalls in a drawer.

First, batch by size and type. Do all the 4 x 6 prints at one setting, then all the small ones, then the film. Changing resolution and holder for every photo is what makes people quit. Many scanners will detect several prints laid on the glass at once and output them as separate files, which is the single biggest speed win available.

Second, separate capture from restoration entirely. Scan everything first, on its own, over however many sessions it takes. Only when the whole box is captured and backed up do you start editing, and then only on the photos that are worth the time. Most boxes contain perhaps twenty images anyone will ever look at closely. Restore those. Archive the rest.

The archive is the deliverable. The restored versions are a nice extra, and they can be redone at any point in the next fifty years. The prints cannot.