Visual content	Issues for visual content	Image production	Image acquisition	Image manipulation	Image creation

Film scanners have computer interfaces with similar controls to flatbed scanners. They are for scanning images from film, usually 35mm. They can produce very high quality, high resolution images, and may have an adapter to support batch scanning of mounted slides.

As discussed in Using a flatbed scanner, a flatbed scanner with a transparent media adapter (TMA) will allow you to scan images from film; however, it is not ideal for scanning 35mm slides. To get sufficient printable image size, 35 mm slides need much more scanning resolution than a 600 ppi TMA can provide and need a dedicated 35 mm film scanner, which typically offers 2400 to 2800 ppi capability.

Scanning film is better than scanning prints, because scanning the film is using the original image, but the print is a second-generation copy. Also, film has greatly more detail and contrast available. Most film is capable of over 3000 ppi, compared to only about 300 ppi for colour photo print paper. The 35 mm film is a smaller original, so it must be enlarged more, about 4 times more than a scanned 6x4 inch print, to get the same image size at the printer. However the film and film scanner has well over 10 times more capability to do it.

For example, a full frame 35 mm slide scanned at 2400 ppi will be about 3400x2200 pixels, and about 22 megabytes. This will scale to around A4 size at 300ppi.

If the images to be scanned are for web use, the enlargement does not need to be as drastic as scanning for print. The slide could be scanned at 240ppi to be an adequate size for web use (about 340 x 220 pixels).

The interface for a film scanner has similar controls to that for a flatbed scanner, with settings for file colour mode (colour or b/w), film type (positive or negative), cropping, scaling and resolution. The image enhancement tools (for adjusting tones, colours etc) are usually more advanced in film scanning software, as it is aimed at the professional market. Standard functions in film scanning software include autofocus, autoexpose and sharpening, as well as accepting plugins, such as Digital ICE which have specialised filters to remove scratches, dust etc from scans.

Film scanners are sometimes equipped with bulk loaders that allow many mounted slides to be scanned as a batch.

Film scanners are very much more expensive than flatbed scanners, so unless you need to use it frequently, it may be more economical to access a film scanning service (try the multimedia or education technology department at your institution, or go to a photo processing laboratory).

Summary:

• A film scanner will produce a far superior scan from 35mm film than a flatbed scanner.
• Film scanners may have some special functions such as: batch scanning and specialised filters.
• Film scanners are expensive, so consider other options before purchasing.