Digital photography and film scanners

From analog to digital photography

On the verge of the turn of the millennium a new age has begun for the art of photography: the well approved principle of exposing highly sensitive film and developing this film in a laboratory in order to make color prints or slides, gives gradually way to the upcoming digital photography. The market share of sold digital cameras compared to analog cameras grows more and more.

Digital cameras become more and more low priced, the resolutions however higher and higher. While for a private person it is a tough choice concerning the price if to buy a 2 or 5 megapixel camera, there are already camera models with 10 and more megapixels for the professional user.

If you take pictures with a digital camera once they are in the computer you have all the possibilities of the digital world: Modern photo printers produce color prints in approved quality; slide shows can be created easily; the images can be edited, manipulated and retouched; you can even watch the photos on a television or video projector.

Even if the digital photography is a faszinating topic there is still one problem left, i.e. what to do with one's old photos, with old negatives and slides. Lots of slide magazins have been lingering in an old closet for years or decades, respectively, without having been touched or watched one time. Unlike a good red wine photos and films don't become better with growing age. Its colors yellow and fade, blisters and mold form between plates of glass, the layer of dust on slides becomes thicker from year to year. That's why it suggests itself to bring the old films somehow into the computer in order to protect them from further loss of quality permanently.

How can old photos be digitized?

If you want to bring your old analog photos in your computer, you will find several possibilites, which mainly differ in quality. A flatbed scanner belongs to the base equipment of a computer user. The price of flatbed scanners starts below 50 €. The resolution often reaches several thousends of dpi. With such scanners color prints may be digitized in good quality.

You can expect a much better quality if you don't scan the color prints but the negatives or slides directly. In order to to this you need a particular scanner which can process not only reflective material like paper prints but also transmittive films. Good flatbed scanners have a transparency unit included which incorporates a second light source. Such scanners can digitize both prints and negatives and slides. The scan quality for film material, however, still lacks in spite of a high scan resolution, since these flatbed scanners don't have a high-class optics and their density range is too small.

If you demand optimal quality you should take a special film scanner, which is constructed only to handle transparent film material. There are not too many film scanner models on the market, let's say about 20. The prices start at a couple of hundred Euros and reach almost five-digit Euro amounts. You cannot scan reflective material like paper prints with film scanners; they are only built to handle transparent media like negatives and positives.

How does a film scanner work?

Film scanners are special devices for digitizing mounted slides or negatives. They have specific film holders and adapters for film strips, film rolls, mounted slides or film cartridges, respectively. Film scanners are distinguished by extra high resolutions and high-class optics. Additionally, film scanners have a much higher density range than flatbed scanners, since on a mounted slide, for instance, the difference between the brightest white and the darkest black is much bigger than on a paper print.

Film scanners have optical resolutions of 4000 dpi and more. What are such astronomical resolutions good for? If you scan a 35 mm negative (dimensions: 35 x 24 mm) with a standard printer resolution of 300 dpi, the image would have the size of a passport photograph when printed out with 300 dpi. In order to receive a print with at least postcard size, you need at least the threefold printer resolution for the scan, i.e. 900 dpi. With a scan resolution of 2800 dpi you are able to produce high quality prints up to 30 x 20 cm, and with 4000 dpi resolution you can even enlarge the photo up to 30 x 40 cm in high print quality. High scan resolutions are also needed if you plan to enlarge parts of an image.

Modern film scanners come with a bunch of image correction possibilities. Dust and scratch can be corrected automatically, colors can be restorated and underexposed photos can be adjusted.