Nowadays, many manufacturers offer scanners that are specifically designed for the capture of negative and 35mm slides directly from the film. Are those really worth it? In this article, we will review these such devices.
The main difference from standard flatbed scanners is that photo films are translucent. As a result, reflection cannot be used as process for the scan.
Usually, flatbeds light the image with a calibrated white light source (fluorescent or LED lamp) and measure the reflected colour and intensity. Here, with translucent films, most of the light passes through, thus producing false scan reading.
Flat bed scanners
To solve this, some flatbed scanners incorporate a lid with built-in white light to scan the film projection. Until a few years ago, the main limit for this process was that of the scanner itself: the optical resolution.
Typical resolutions (around 600 pixels per inch) did not allow for high resolution images: a 35mm film has an average image area of 1 x 1.5 inches, so images around 600 x 900 points were all that could be achieved. Of course, interpolation was available, so intermediate points could be made up to increase resolution - but this was an artificial process.
Introduction of film scanners
The alternative was to use specific film scanners. Optical system was improved, so that scanning resolution could be much higher - typical from 1800ppp on. Most scanners include some sort of "trays" to mount the film flat at a given distance.
Fine focusing is also provided. Furthermore, compensation per software (for example, for a specific film-brand celluloid colour) is provided.
Bundled software usually provides higher output quality, with added features as scratch & dust removal. Multi-pass scanning will increase quality reducing such as colour noise. Light source is designed to fit the application, providing more precise results than with flatbeds. You will also require less space on your desk - but do consider the free-space needed to handle the film trays.
Which one is best?
Nowadays, both flatbed and film scanners are able to reach much higher resolutions. With 3,600ppp, you can get quality prints up to 12 x 18 inches (30 x 45 cm). Some scanners will provide up to 7,200ppp (even 9,600ppp)- but be careful with image file sizes!
Colour resolution of 14 - 16 bits per colour is also recommended to produce RAW images that can be edited afterwards (for example, to create HDR images). Scratch and dust removal are nice features, too.
Check the products by Plustek, Reflecta, Agfa and Cannon, among others.