Digitization is key to make and keep our cultural heritage accessible and to preserve it for the future. Since it’s a labour intensive task, you want to do it once and do it right.
Cambo RPS copystand with a Phase One IQ4 back and Rodenstock’s 138 Float. This set-up doesn’t leave much to be desired.
Standards like Metamorphosis and FADGI provide guidelines to ensure that all involved in the digitization process are on the same page. Depending on the object’s size and quality guidelines – not every application requires a FADGI 4-Star rating – one can simply calculate the amount of pixels required to meet the desired standard. And although the set-up shown above combines excellent quality with a very efficient workflow, not every archivist will need a 150mp digital back. However, every serious archival job does require good lenses. Or we may say: Purpose-built lenses.
A lens dedicated to archival work, only has to do one thing right. No fast aperture nor AF needed. Optimum quality within a given – mostly quite limited – magnification range is what it needs to provide. That’s where our RPM-System comes in. It’s a helical focusing mount with a Fujifilm GFX bayonet on one side and an exchangable lensplate on the other. It enables fitting of many (legacy) lenses. Like this Schneider Makro-Symmar, just to name one, which performs excellently when digitizing film. By adding spacers it’s set-up for the required magnification.The helical has a locking screw, the spacers are secured with screws as well. It’s pretty industrial and for good reasons; when the operator comes back from a coffee break, work can be resumed without worrying about focus.
A quote from the FADGI guidelines for digitizing cultural heritage materials: “As digital sensors become available in ever higher pixel counts, the quality of the lens becomes a critical factor in actual system resolution. It has reached the point where the resolution of digital cameras and scanners may be limited by the performance of the lens, and in some cases a theoretically perfect lens cannot match the resolution capability of available digital sensors. More pixels on the sensor may not relate to increased resolution in the digital file.” Another statement: “All lenses are designed and optimized for specific applications (…) lenses designed specifically for digital flat field imaging are best “.
The good thing is, there are plenty of those lenses available and you won’t always need the latest and greatest glass to yield good results. Cambo’s RPM helical provides the link between these (sometimes older) lenses and the aformentioned demanding modern sensors.