You may have noticed the term “drum scanner” kicking around this and other websites, but rarely explained versus the usually high prices these scans carry. Basically, there are two separate technologies at play used in capturing image data into a digital file, and it’s important to understand the distinction in order to figure out which is right for you.
CCD stands for Charge Coupled Device. Basically, it’s a light sensitive chip that takes a picture of parts of the image and then collates these pictures into a file. It captures the entire light spectrum all at once and is the technology (along with the similar CMOS) used in digital cameras. All flatbeds on the market, as well as the Imacon/Hasselblad Flextight line are CCD based. CCD scanners typically are faster and more economical than their PMT based counterparts (see below). They are great for high volume workflows, especially on tightly controlled originals where shadow detail and maximum resolution is not a top priority. Unlike commercially available prosumer flatbeds, which usually bench test at a fraction of their advertised resolution and DMAX and are inconsistent across the bed, our Heidelberg Nexscan F4200 holds 5080 true optical dpi from edge to edge. In addition, it features a mirrorless optical path for the most natural and sharp rendition of originals.
ProScanNY has the best equipment available, professionally maintained and operated, for top quality output every time.
Drum Scanners are based around PMT’s – Photo Multiplier Tubes. Basically, there is a dedicated image sensor for each channel – Red, Green, and Blue, which record image data a single pixel at a time and reassemble them into a finished image via aperture controls and fiber optics cables. This technology affords maximum sharpness and low noise due to the nature of the electronic system and cleaner optical path. They offer user controllable apertures and focus for tight control on grain rendition according to the characteristics of the particular original being scanned. Drum scanners are also superior for reading into dense, dark areas of the negative – the best will pull detail out that you aren’t even able to see on a light box. For no-holds-barred maximum quality files, a drum scan is the way to go.
Resolution is also superior, our Heidelberg Tango resolves to 11,000 dpi, which is enough resolution to zoom in on a single grain in your film without being able to make out a single digital pixel. In practice, optical resolution of film tends to max out around 6,000 dpi, but the extra pixels are essentially optically interpolated due to the aperture based imaging system of the scanner, giving a clean and pixel free enlargable file. They also have a natural, dymanic feel to the tones which most closely approximates a darkroom print on-screen. All drum scans are wet-mounted in a specially designed, emulsion-safe fluid, a process which ensures total film flatness and hides scratches and imperfections in the negative.