Scanning and Proofing for Fine Art Reproduction
A large part of getting the highest quality imagery for fine art reproduction depends upon using the best equipment, but we also walk through a few steps and use a couple of our own techniques to create consistently color-accurate, precisely-detailed captures.
The process of capturing fine art in scanning and photography starts in a controlled shooting studio by limiting light pollution from external elements, metering directed sources of light, and making adjustments that create an even distribution of illumination across the scanning surface.
In order to get the best resolution, color accuracy, and detail from our Better Light scanning system–our primary tool for capturing high resolution imagery–we utilize complimentary North Light high intensity ceramic discharge copy lights. North Light’s copy lights were developed as a continuous light source specifically to be used in fine art reproduction with a scanning back. North Light’s ceramic discharge lamps evenly distribute light across the scanning surface while minimizing the UV, IR, and heat degradation that plagues tungsten and HMI light sources. The North Light copy lamps also offer a high color rendering index value between 92 and 96, indicating exceptional accuracy in displaying or rendering color when compared to a reference.
With two continuous North Light systems parallel to the artwork, and a light-controlled shooting environment, we then sample illumination across the scanning area with a light meter. Using a meter to sample values across the scanning subject allows us to more accurately measure the levels of light distribution across the plane and make adjustments until they are even. With the North Light towers parallel to the scan subject, the distance and angle of light can then be further manipulated to reveal greater depth, tone, interference characteristics, and features unique to each work of art.
Specifics about Scanning
To get the best quality and highest resolution images required for fine art reproduction and archiving, we use a Better Light Super 6K-HS scanning back seated on a standard 4×5 Horseman camera body coupled with a Schneider Apo-Symmar lens. Apochromatic lenses, like the Apo-Symmar one we use, correct for chromatic and spherical aberrations by focusing all color values into the same plane, offering sharper resolution and a higher degree of color accuracy as light waves naturally hit the lens at different angles.
Scanning backs offer advantages over digital cameras for capturing images used in fine art reproduction, not only because the camera body and lenses can be changed for different shooting needs, but also because they scan a surface over a period of time using a linear or multi-linear array to collect light reflected at every point, or pixel. With light collected and measured independently for each Red Green and Blue channel, the resulting image is rendered extremely sharp and color accurate, even when a print is eventually enlarged. Though scanning backs can take several minutes to process a capture, and also require stringent lighting considerations, the resulting image is significantly higher in resolution, quality, and color accuracy than when created with a digital camera.
Scanning backs measure light waves as they’re presented and assimilate the data into an image that does not include post-capture modifications, whereas digital cameras typically modify an image using internal programming and software algorithms to make the capture look similar to what was visualized. Periodic calibration of the scanning back and the utilization of custom color management profiles also imparts greater precision in capturing light values relative to the shooting space than with a digital camera. Raw images captured with a scan offer the most unaltered or native form of an artwork suitable for Giclee print reproduction, archiving, and graphics editing.
Though a scanning back will provide the most unaltered form of an image, it still requires a few critical adjustments to both the ViewFinder software and the equipment it optimizes before a scan can begin. We first perform a pre-scan in order to visualize the artwork on a monitor and make additional adjustments before performing the lengthy full scan. Here, adjustments to the ISO are made based on the white content of the individual work being scanned, a calibrated re-check of the focus is identified through sensor measurement, and neutral balance is attained by sampling known values on a color checker card. Before a full scan begins, saturation qualities and contrast characteristics can also be further manipulated by changing the tone curve to a different one, or by making specific adjustments to programmed ones.
Once the software and equipment have been calibrated, we then perform a full scan, which can take up to several minutes. Because a full scan takes a long period of time to process, the lighting conditions in the studio must remain constant, otherwise anomalies will be included in the final image.
The Proof is in the Print
A print driver maps the scan, or digital image, and blends pigments to print a reproduction, so even with the most color-accurate and highest resolution image available, the Giclee that prints has only as much fidelity to the original as the driver allows. To overcome this disability in the reproduction process, we use ColorByte’s Raster Image Processor as well as closed loop color management system profiled monitors to ensure the highest level of accuracy in mapping the image and translating the digital capture into a physical Giclee print.
After a scan, the raw high resolution image that’s captured is then printed and compared to the original artwork on a light-controlled proofing table. A proofing table offers the last leg of consistency in the process, as it provides a stable source of calibrated and directed light useful for making reliable color matches with a wide range of materials. Though it can take one print and a review to proof a work, it can also sometimes require additional editing of colors or values in Photoshop to match the original work or meet specific interests of the client.
The Betterlight System
Utilizing superior optics (Shneider lenses), Northlight lighting, a Horseman 4×5 Camera Body and a sturdy tripod, the system provides the ultimate imaging quality available today.
We use the Super6K back-HS rated at 216 Megapixels. This system allows precise control of exposure, image tone, color clarity, and dynamic range.