Digital negative (transparency)

The digital negative is a new technology which allows photographers to use digital files to create negatives on transparency film. These negatives can be used to contact print, or in some cases if the negative is made large enough (about 4x5") they can be enlarged. It is different than the Digital negative file format, although this format may be used to create the digital images.

Creation of Digital Negatives

Before creating a digital negative it is important to know the process to which it will be applied. Since contemporary inks and printers cannot cover a gamut as wide as traditional silver negatives and it is imperative that each process have its own tonal curve to apply to a photograph so that the photographer can take full advantage of its gamut. Also, different processes react differently to colors; sometimes photographers print out a monochromatic negative in a specific color to get a specific contrast range. For example, some use purple inks and low contrast curves for the small gamut of cyanotype printing, while the platinum/palladium process necessitates a high contrast curve that works best with green ink. Before the color cast is added, however, it is important to remember to invert the image to ensure that the negative prints a positive if contact printing (some also flip their image horizontally since the final print will be a mirror image of the negative), or sometimes it may be left as a positive (in the case of a positive image on a dry or wet plate).

The photographer has a number of options to create a digital negative. Usually, the process involves a lot of testing and reprinting. Chemical procedures must be standardized to allow for repeatable results. First, a tonal scale is printed out on the transparency film and this is used to create a print using whatever process is being tested. Next, the print is scanned and the resulting tones are examined either by the photographer or by a program and a new contrast curve is generated to compensate for whatever inadequacies that may exist in the first negative. The photographer may also decide here to use a different ink color. The new negative is printed and again is tested. This process may continue for as long as the photographer deems necessary. The final negative should create a final print that has both blacks and whites, and a smooth tonal range between.

Uses

Most commonly, digital negatives are used to create contact prints. The negative is made to be the same size as the final print, and sandwiched printer ink-to-emulsion in a contact printing frame then exposed under a UV light source. They can also be used to create positives (where the initial digital file is not inverted) to make positives on emulsions such as collodion processes. Or, they can be used to create negatives that will be enlarged and used to create traditional darkroom prints. The problem with this, however, is that the negative must be large, at least 4x5". The reason being that since printers cannot spray small enough drops of ink to ensure detail in smaller negatives. Small digitally printed negatives result in grainy and blurry prints.

Advantages and Disadvantages

Digital negatives offer many advantages. Photographers can enjoy the ease of shooting with a digital camera and editing digitally while still working with alternative or traditional photographic processes. Small, analog negatives can be scanned and enlarged digitally to create new negatives instead of using the traditional enlarging film that must be processed in a darkroom. If the photographer has an advanced understanding of the emulsion they are using they may use different colors in areas to create contrast differences when printing their negatives, similar to using colored filters on black and white film. In this case however it is similar to using a red filter only on the sky and perhaps a green filter on the grass, all at once (for example; the red filter would darken the sky and the green filter would lighten the grass). Mark Nelson's digital negative process covers this extensively ^[1]

Another advantage to digital negatives is their reproducibility: if a photographer ruins their negative with chemicals they can simply make another without having to reshoot the original negative.

Disadvantages occur mostly because of printer limitations. As mentioned above, very small negatives tend to be blurry and grainy due to large ink droplets. Also, some inks can create banding not evident in the negative but obvious in the final print. Epson K3 Ultrachrome inks have shown to work very well in the creation of digital negatives.

Some types of transparency film work better than others: it is important to ensure that the film does not have any agents in it that block UV since this will allow only a very small amount of necessary UV to expose the print. Some films do not respond well to inks and even after drying will smudge and smear.

Notes

1. ^ Mark Nelson, Precision Digital Negatives http://www.precisiondigitalnegatives.com/