Tromleskannere

Tromleskannere, also known as drum scanners, are a type of high-quality image scanner. They are characterized by their cylindrical scanning drum, onto which the original image, typically a transparency or reflective artwork, is mounted. A light source, usually a powerful halogen lamp, shines through or onto the original, and a set of sensors, often photomultiplier tubes (PMTs) or charge-coupled devices (CCDs), capture the reflected or transmitted light.

The drum rotates at high speed, while the scanning head moves incrementally across the length of the drum. This mechanical precision allows for extremely accurate color separation and detail capture. The primary advantage of tromleskannere lies in their ability to achieve very high optical resolutions and a wide dynamic range, making them ideal for professional photographic reproduction, fine art scanning, and high-end commercial printing where exceptional image fidelity is paramount.

Due to their complex mechanical construction and the need for precise mounting of originals, tromleskannere are generally slower and more expensive than flatbed scanners. They are often found in specialized imaging studios and pre-press houses. The technology, while still in use for demanding applications, has seen some decline in market share with the advent of increasingly sophisticated flatbed and digital camera-based scanning solutions. However, for certain niche applications, the unparalleled quality offered by drum scanners remains unmatched.