Sepia Filter for Photos

Where sepia comes from

The name is the Greek for cuttlefish, whose ink gave artists a warm brown long before photography. The photographic sepia most people picture came later, from toning: a finished black-and-white print was bleached and re-developed in a sulphide bath that turned its metallic silver into silver sulphide. That changed the colour to brown and, usefully, made the print far more resistant to fading — which is part of why so many surviving 19th- and early 20th-century photographs are brown rather than grey.

Two ways to do it digitally

Classic sepia is a fixed colour matrix published in the W3C Filter Effects specification and used by the CSS sepia() filter and most photo apps. Each output channel is a weighted mix of the input red, green and blue — red out is 0.393 R + 0.769 G + 0.189 B, for example. Because those weights add up to more than 1 for red and green, bright areas push past the top of the scale, which is why this style looks punchy and yellow, and why pure white comes out cream.

Toned print works the way the darkroom did. The image is first reduced to brightness alone (using the BT.709 weights a modern display uses), then every grey level is placed on a ramp from a deep brown in the shadows to a warm paper colour in the highlights. Nothing clips, highlight detail survives, and the result reads as a print rather than a filter.

Getting a convincing old-photo look

• Start from a well-exposed photo. Sepia flattens colour into tone, so a photo that is already dark gets muddy. Fix it first with the Brighten Image tool.
• Pick subjects without obvious modern details. Phones, cars and logos give the game away; people, buildings and landscapes carry it.
• Use Toned print with a little fade. Real aged prints rarely have true black. A 20% fade does more for the look than any amount of extra brown.
• Add a light vignette, not a heavy one. Early lenses fell off gently towards the corners; a strong black ring looks like an app.
• Finish with a border. A white or cream margin from Add Border to Image sells the print effect.

Sepia, black and white, or monochrome?

Black and white means no hue at all — only grey. Sepia is a kind of monochrome: one hue (brown) at different strengths. Cyanotype blue and selenium purple-brown are other monochromes. If you want neutral greys, a one-bit black and white for a stencil, or a red-filter look for dramatic skies, the Black and White Image Converter has those modes.