Instead of being made up of gradation tones like typical photographs, stocks and bonds are normally composed of fine lines of black or singular colors. Depending on scanning resolutions, images of collectible securities tend to come out too dark, too light, and/or too contrasty. Moreover, images tend to be overly yellow.
This section discusses some of the reasons for those problems and some of the tricks you can use to improve your results when scanning certificates in your collection.
Not every collector has a scanner, but almost everyone has a smartphone with a camera. A really good camera. No matter how you might make images of your certificates, you will sooner or later want to improve them. This is particularly true with photographs.
Unless taking photos with a camera outfitted with a very pricey lens, images of certificates will always show several problems such as shadows, and areas that are too light or too dark, Handheld cameras and smartphones will generally produce areas of uneven focus, especially if the camera is close to the paper. Virtually all photos will make certificates appear non-rectangular. And then there are color shifts due to lighting.
While scanners overcome many of the problems typical to photographs, they have their own separate problems, one of the most common being color shifts toward yellow. Many scanners are simply too small to scan complete certificates in one pass. If scanner covers are not closed all the way, previously-folded certificates often lift off the glass and scans show out-of-focus areas.
Not all of these problems can be overcome after-the-fact with photo manipulation software, but many can. This section discusses software possibilities and shows some of the tricks I use.