What follows here is an illustration of just one of the many skills taught to Salisbury Museum volunteer scanners. To obtain perfect digital images from the museum’s vast collection of negatives, there are a number of such skills to be learnt.
A flatbed scanner which scans negatives usually comes with a number of plastic templates for the various sized negatives. These templates attempt to keep the negative aligned to the vertical and flat, as well as allowing automated scanning of multiple negatives placed on the flatbed. The scanner hardware/software senses which template is in use by first scanning some plastic codes at the top of the template. Thus, if you are not using any of these templates, one must not have anything in the first ½ inch of the scanning flatbed, otherwise the scanner gets confused. It is far quicker, easier and more productive, not to use the plastic templates, but read on.
Software such as Vuescan can easily correct any misalignment of the negatives from up to 5 degrees away from the vertical, more than adequate. Any negative placed on the scanner flatbed must therefore be at least ½ inch away from the top edge of the flatbed where the scanning illumination starts. The first image here of Salisbury Cathedral, with the top of the tower covered in scaffolding, was produced by placing the negative by itself on the flatbed. It looks as though the Cathedral is bending in the wind. I can assure you that this was not the case.
The heat from the scanning head has curled the negative whilst scanning it. The remedy is to have a piece of toughened glass, made with ground edges, and the correct size to fit the flatbed, minus the top ½ inch. Salisbury Glass specially made this for the Museum. Now one can put the negative on the scanner flatbed, position the negative and then place this sheet of glass on top, being very careful in letting the glass descend the final ¼ inch not to disturb the position of the negative. A technique that also had to be taught. The negative is now constrained to remain absolutely flat whilst being scanned. The second image here now shows the Cathedral without distortion, as the negative has not curled.
I thought that this was a nice example to illustrate one of the skills acquired by being a Salisbury Museum volunteer scanner.
Best wishes, Alan