Using a Flat-Bed Scanner to Capture JPG Images of Jewelry, Coins, & Other 3-D Objects
I collect scrimshawed whale teeth, and needed a repeatable method of a making high-resolution images of an entire tooth [Image #1], as well as sharp, close-up images of minute detail, such as an artist’s signature [Image #2]. The same requirements are needed for pocket watches, broaches, coins, necklaces, rings, silverware, pocket knives, small art objects, etc.
Using a digital camera would involve a macro lens, shadowless lighting, a tripod, a background, etc., and even then, repeating or improving an image is difficult. But using a standard, glass-topped flatbed scanner allows me to capture exactly what I want, with “preview” to make small adjustments, and high Dots-Per-Inch (DPI) close-up JPGs.
Most of my scanner images are captured with the lid completely removed. This provides a jet-black background, which contrasts nicely with my ivory [Image #1] or jewelry [Image #3] subjects. For very dark objects, a light-colored cloth may be draped across the object for outline contrast.
I am currently using PaperPort 11 software, and a Visioneer One Touch 9220 USB scanner. I purchased both via online auction sites. Any good scanner and any good software program should work.
The key to good scans is high resolution. The (side-to-side) width of an object makes no difference in scanning time, but the (start-to-end) length will effect scanning time. The larger the object, the smaller DPI needed; and the smaller the object, the higher DPI needed to make a decent-sized, detailed image.
I always lay a narrow, 6-inch steel ruler along bottom (start) edge of glass [Image #4], then place my items parallel to, and 1/8th-inch from ruler. For an item 2-inches to 3-inches deep (from ruler), I use 300-dpi; 3- to 6-inches = 150-dpi [Image #5]; >6-inches = 75-dpi. For smaller objects of 1-inch to 2-inches, I use 600-dpi [Image #6], and for items less than 1-inch (such as signatures, hallmarks, etc), I use 1200-dpi [Image #2, which is on backside of scrimshaw in Image #1].
Sometimes I use transparent tape to hold a round-bottom item in exactly the right position & attitude to capture the desired image. I use the preview to make adjustments until I am happy with position, then use the PaperPort software to crop tightly, and make a scan at correct DPI.
Once an image is captured, I again use the PaperPort software to zoom-in to a very high magnification. Now I use the black “pencil” function to erase dust spots & tape images in background. Once it is clean, I save the edited image. If needed, I rotate the image to proper orientation for viewing.
Letha Berry (LovesAntiqueDolls) has recently attempted scanning, and has shared a scan of her 13-inch tall, French Fashion Doll by Barrois, circa 1865 [Image #7]. She is quite pleased with the detail captured by scanning.
Good luck, and good scanning!