Digitization of Petőfi-daguerreotype

2019. 03. 21. | Egyéb kategória

According to our current knowledge, Gábor Egressy, an actor and amateur daguerreotypist, took the daguerreotype of Petőfi in the summer of 1845. Its size is not standard, 64×84 mm, between “6th” or “8th” sized plate. G.R.B, the creator’s hallmark is affixed in the sheet of the silver-plated copper with the number of 40 which refers to the amount of silver (signing that 1/40 of the whole weight of the silver-plated copper is silver). Since it was taken 173 years ago, the troubled picture has suffered from many damaging. During this period there were a few attempts for restoration of the picture, for example in 1955 Károly Escher restorated it, too. Now the daguerreotype is in the photo collection of Petőfi Litrature Museum and is kept in a special package that was made in the style of old Hungarian restoration packaging for daguerreotypes by József Ormos and one of his collegue.

The sheet of the silver-plated copper coated with photosensitive compound and iodine-bromine and fumed with mercury vapor shows its model from his side as it was a usual technique for daguerreotypes. Its exposition time (considering the possible technologies of that time) could have been between 10-60 seconds.

Daguerreotypes are especially sensitive for physical impacts: touching or wiping might destroy the image or at the edges layer might start to come off. Moving the picture or improper storage are not the only danger: they are overly sensitive to sulfur or other pollutants in the air that cause silver oxide or silver sulfid precipitation. These chemical processes caused by air result the image slowly darkening or total disappearing in critical cases. That’s why optimum storage conditions for daguerreotypes are essential: they should be kept in hermetic and acid-free medium.

Petőfi-daguerreotype should be digitized continuously with the most advanced technology available. As the changes of its density cannot yet be controlled, applying densitometer is not a good solution for this technique. However, cyanid used several times for cleaning this image might be the source of more damaging process (which is a plus to the damages had been caused in previous occasions). The aim of using the latest photographic technology is to maintain the signal-to-noise ratio on the reproduction and to see more of Petőfi and less of the outer mechanical (scratches) and different chemical damages.

In January, 2018, the Cultural Heritage Digitization branch of Tripont had an attempt to digitaze  Petőfi-daguerreotype using PhaseOne XF IQ280 camera syístem in the digitization studio of Petőfi Literature Museum. The result speaks to itself. The most detailed image was taken showing such details that had never been visible before of the original picture.