I've come up with a new technique for removing black spots from prints. This problem, and my new solution may be somewhat foreign to anyone shooting digitally. But for those of us old school analog photographers, this has been an ongoing problem. If a piece of dust or debris is on the surface of the film during exposure, this blocks light from striking the light sensitive emulsion when the film is exposed and the picture is being taken. This results in a clear spot on the negative. Of course when the negative is then exposed with an enlarger onto a piece of photographic paper, the opposite of a clear spot... a black spot... is created on the print. These are very difficult to deal with.
If dust or debris is on the negative of the paper during exposure of the print, this results in a white spot on the print. Spotting dyes and fine brushes can be used to eliminate these white spots and this is almost always required,,,, to some degree, on every print. The black spots used to ruin some negatives as they were not so easy to deal with.
Over the years, one of my favorite films has been the now discontinued [in 1999] Kodak High Speed Infrared. I still have several hundred 4" x 5" sheets of this film in my freezer, and will continue to use it for a few more years to come. This emulsion is very susceptible to fingerprints, and accumulates a strong static charge. When the film holder is inserted into the view camera prior to exposure, and the dark slide is pulled to take the picture, it is not uncommon for any dust particles and fine hairs that may be present inside the camera, or on the surface of the film holder, to be drawn onto the surface of the film and cling there, creating these annoying clear spots on the negative, and black spots on the resulting print...
One of the images that I have been working on for Procession West was shot on this film. It was on the verge of being removed from the show as there a literally about a hundred small little black spots on the print that resulted from dust on the negative during exposure. Here is a shot of the printing in progress, and a close up view of some of these dust spots...
Potassium Ferricyanide is commonly used for localized bleaching of select areas of a print. This is typically brushed onto a section of the print, allowed to act for a few seconds, and then rinsed away. The result is that this chemical lightens an area of the print. It takes some experience to undertake this process as it is easy to take it too far and end up with a very uneven bright spot on the print. I decided to try and use this bleaching solution to get rid of these little black spots. The question was how to apply the bleaching solution just to these spots, without getting it all over the adjacent parts of the print. Then I remembered the technical pens that we used to use back in the good old days when drafting was done by hand. This was years ago... before the days of AutoCad software and computer plotters. We used to fill these technical pens with ink and the result was lines of very uniform width and density on our architectural and technical drawings. I thought that these pens would be perfect to apply very controlled amounts of this bleaching solution. I still had a couple of these pens left from back in the day, and I checked on line with a number of drafting supply stores to try and find a few more. They are pretty difficult to find, as similar to film based photography, digital drafting has taken over from the old methods of drawing by hand. I finally found a few, with various nib sizes, but they cost me over $50 each. Here is a close up view of one of these Marsmatic 700 technical pens...
The idea that I came up with was to fill the pen with a dilute solution of potassium ferricyanide, and then repeatedly apply this solution, with the pen, to all the little black spots on the print. With this particular image that was very labor intensive as I actually had about six copies of the print, and there were literally over a hundred of these little spots on each print. In addition to that, the bleach solution had to be applied a few times until it eventually bleached away the little spot. After three or four applications of this bleach solution, the print was fixed for a second time in a solution of ammonium thiosulfate. This not only stopped the bleaching process, but also intensified it. When I was done with this step, each print now had about a hundred little white spots, instead of little black ones. These spots are much easier to deal with as they can be spotted away by traditional methods, using a fine brush and spotting dyes, or spotting pens. I see tremendous potential for this process as I can now use it to salvage prints from negatives that would have otherwise been unpresentable. This black spot problem, although most common and pronounced with the infrared material, also occurs to a lesser degree with other films. Here is a close up view of the bleached away black spots on the print...
Another consideration for these technical pens would be to use them to apply an opaque dye to the surface of the negative. This would create the same result... a white spot on the print instead of a black one. The advantage to this approach would be that it would only have to be done once... to the original negative... and then all resulting prints would automatically have the resulting white spots. The down side would be that the white spots on the print would all be bigger. The opaque dye on the negative would be the size of the nib of the technical pen... in the range of 1/3 to 1 mm in diameter. But this would increase in size on the finished print by the amount of enlargement that the negative is given in printing. At least two or three times in a large format negative, and even more on a smaller negative in roll film format. I haven't tried this alternative method yet, but it is worth experimentation in the future.
I'm really proud of myself for coming up with this idea and have been really busy of late bragging and patting myself on the back...!!
