One of the great things about technology is the ability of new devices to make our lives better. In the world of photographic media, technology allows us to take the memories of the past and preserve them for a digital future. Photographic film and slides, for example, can be captured and preserved through the use of a photographic slide scanner. But before you invest a lot of money in such a scanner, there are some things you need to know.
DPI is Everything
DPI, otherwise known as dots per inch, is a measurement of image resolution; the higher the resolution, the higher the clarity and color of the image. The best photographic slide scanners have high resolution rates built right into the hardware without the need for software enhancement.
Even if a specific scanner does claim higher DPI values through their proprietary software, the higher resolution will not be borne out in the finished product, and your images will still be poor. Therefore, the best results with your slides and film require a scanner with a DPI of 2700 or more. Believe me - it will be worth the additional cost.
Media Loading Capabilities
Another thing to look for in a photographic slide scanner is the ability to load multiple types of media. Some slide scanners will only accept 35mm strips while others can be loaded with standard slides, microscope slides, microfilm, 120mm film, etc. If you can find a scanner with the ability to batch load your slides, even better. With this feature, you can load a stack of slides in the media loader then go do other things while the machine scans each individual slide. This time saving option means you spend less time watching your scanner work.
Image Manipulation and Software
One of the biggest problems with a photographic slide scanner is something called SPI, or samples per inch. Digital scanners create an image by scanning the media and then dividing that scan into one inch blocks. The scanner takes several "snapshots" of each section, which are called “samples.”
The extremely high SPI rate of the typical photographic slide scanner means you'll be able to see every scratch and blemish on your slide. In fact, such blemishes could be magnified to a point where you don't even want to scan your slides. You can correct these blemishes with a good software package like Photoshop or Gimp, or you can invest in a scanner with infrared capability.
These scanners add infrared light as a fourth channel on the scanner head. Since photographic film is transparent, infrared light will pass through without a problem. But scratches, dust, and dirt, block the infrared light from passing through, allowing the scanner to recognize blemishes and fix them automatically.
Preserving the memories contained on our slides and film has never been easier than it is today. If you have the money, a high-end scanner with maximum DPI and infrared capability is the way to go.