Since the second half of photography during the Victorian time. They had to tone the photos for various reasons. This explains what the popular tone of sepia being used from the age of antiquity to modern day.
Sepia is a dark brown colour that was used as an ink or toner for paintings and in writing. It can range from a reddish tone to a greyish tone. The word sepia is Latin that derived from the Greek word for cuttlefish. Cuttlefish is a marine mollusks cephalopod that can store ink to use for chemical deterrence, phagomimicry, sensory distraction and evasion when intimidating the threat of a larger sea creature. The ink can eject like an underwater smokescreen for its escape. The ink is rich in ammonium salts.
Sepia ink is edible when it’s from the cuttlefish itself. Cuttlefish ink is used in sauces for pasta, rice and seafood dishes to give a briny, savoury flavour. Foods like al Nero di Seppia is a pasta with either squid or cuttlefish black ink.
Natural sepia ink undiluted is a thick dark black ink. Sepia was taken from the ink sacs of these invertebrates and dried immediately afterwards to prevent the inks from turning putrefied. It’s then solved with an alkali solution then filtered to isolate the pigment which is then diluted again with hydrochloric acid. Artificial dyes replaced the natural sepia in modern production. The ink produced is a rich reddish-brown pigment.
Sepia was always used as an ink since the 332 BC -395 AD era in the Graeco-Roman Period or Greco-Roman culture until the 19th century. The technique that was used was Grisaille which was painting entirely used by shades of grey or other neutral tones. When a painting used green it was called verdaille and when it was brown it was called brunaille. It was used as an underpaint of oil painting. En Brunaille are pictures painted in shades of brown especially in the 12th century for the Order of Cistercians when stained glasses were painted after a ban of colour in 1147. Sepia was interpreted as a monochromatic tone.
Sepia was used as an ink, notably by Leonardo de Vinci who sketched and wrote down many ideas on paper that’s now on display in galleries. The first person to use sepia as a toner was in the 18th century, Jacob Seydelmann, a German professor and artist. He used sepia as a wash to enrich the colours in his paintings. This is called tonalism; the practice of painters using muted colours to create a sombre and melancholy mood. It was very popular for painters to do between the 1880s to early 1900s.
Photography with Sepia
Photographic toning is a method to change the colour of a black and white photograph. Analog photography is a chemical process used metal salts base prints like silver prints or iron prints.
Sepia toning was to give black and white photographs a warmer tone and to enhance its archival qualities making it more resistant to environmental pollutants and fading. The warmer tone was to achieve a more sentimental feeling than the stark silver black and white photographs. Therefore, the soft brown tone seen on some photographs was intentional and as the way the photographer wanted it. In some photographs during the American Civil War had a sepia-tone to them to soften the horrors of war instead of keeping them black and white. It still makes photographs look like antiques if applied right.
Silver in the print is converted to a sulphide compound turning it into silver sulphide which is at least 50% more stable than silver. The three types of processes for sepia-tone are sodium sulphide, thiourea (thiocarbamide) and polysulfide. The ones that use sulphur in any way would have a strong sulfuric “rotten eggs / bad fart” smell because of the chemical being exposed to moisture.
Besides polysulfide toners, sepia toning is produced in three stages. First, the photograph is soaked in potassium ferricyanide bleach converting it to silver halide. The prints are washed to remove excess potassium ferricyanide then immersed into a bath of toner which converts the photograph to silver sulphide.
If a photographer wanted a multi-toned image with sepia highlights and gray midtones and shadows. This is called split toning when the bleaching is incomplete. The untoned areas can be treated with selenium or gold.
Selenium chemicals are used to tone a photograph red-brown or purple-brown by converting the silver to silver selenide. Depending on the strength of the selenium compound can make it a redder toner for a light amount or purple tone for a heavy amount.
This was a process that was seen in Daguerreotype photographs for a while. It protected the photograph from damage and made it a bright reddish-orange tone if it was mixed with sepia tone. They were once known as a stronger, sharper tone for the photographic process. Many gold toning processes were patented during the Victorian era. The most common chemical compound used today is gold bromide. A warm black and white toned with gold salts would turn an image a rich bluish-purple colour or a bluish-grey colour.
Sepia in Movies
There are some films that add a sepia tone to them to make it look old, otherworldly or old-timey. Two movies that come to mind are Stalker (1979), a science fiction and psychological film by Andrei Tarkovsky, and Oh Brother, Where Art Thou? (2000), a depression-era styled Homer’s Illiad comedy from the Cohen Brothers. The sepia tone in Stalker was used to distinguish the areas not set in the forbidden zones. The times the stalker stays at home with his wife are set in a high contrasted monochromatic sepia brown tone. In Oh Brother, Where Art Thou? was completely colour graded to a sepia tone wash with some colour that changes the appearance and personality of the film to have a yesteryears look to it. At the time, it was very groundbreaking to do digital colour grading to that scale when the movie came out.
Other films like The Godfather: The Coppola Restoration have a sepia tone to the film to give a touch of nostalgia for the updated colour grading and giving back the movie magic by covering up the some actor’s heavy makeup. And Eureka (2000) is a drama completely in sepia-tone about the psychological trauma three people have after being the survivors of a bus hijacking. Furthermore, the colour grading for the Kansas scenes of The Wizard of Oz used sepia tones to show the comparative difference between the farmland in Kansas the colourful Land of Oz.
Digital Sepia Tone
Most people can add a sepia tone to their photographs digitally through software like Photoshop or through smart phone apps like Instagram or their phones photo editing applications.
In Photoshop, just editing the Hue/Saturation levels or editing the Photo Filter to sepia tone or the Duotone under the Image>Mode to sepia tone. In photo editing apps on smart phones, there are filters that can make a sepia tone. Just remember to convert your photos to black and white first.
In Instagram, if you used the photo filter Earlybird then edit the filter to the following: Contrast: -31, Warmth: +27, Saturation: -100, Shadow: -43. This would achieve a monochromatic sepia tone wash effect in most photos because of the ramped warmth levels and the lowered saturation in the photograph. Even if the setting were at 100 Warmth and -100 Saturation it should work out fine. Also, you can add a vignette for a finishing touch.