A view from inside the mirror box assembly of AaI&A’s first accelerated light fade test unit.
Project Successfully Funded!
Ok, it’s not magic, just a simple optical trick done with a mirror assembly like you can sometimes encounter at a carnival fun house. By arranging mirrors at 90 degree angles one can create multiple virtual images of the same object that appear to go on forever. When the concept is applied to an accelerated light fade test unit, the optical result is very uniform illumination at the test sample surface. The large, evenly lit surface is perfect for exposing digital prints to uniform doses of light energy. The photo shown above was taken inside Aardenburg Imaging’s first accelerated light fade test unit looking up from that exposure plane. AaI&A’s shoestring budget precluded commercially available equipment. Constructing a viable “home grown” unit is not difficult, but the devil is in the details. The unit must also achieve humidity and temperature control. Numerous technical decisions also have to be made regarding light source, light level calibration, and ultraviolet (UV) energy levels at the exposure plane.
Aardenburg’s primary mission is to create a well documented digital print archive and to conduct real world digital print research. Why then venture into the area of light fade screening tests? Well, it is obvious that a lack of practical consumer benchmarks on image permanence exist today for the new digital print technologies. In particular, combinations of materials that serious amateur and professional photographers want to use often go untested. For example, I recently tried some Epson Exhibition Fiber paper in my Canon ipF5000 printer. The Epson Exhibition Fiber paper is one of several new professional inkjet papers designed to mimic the look of traditional photographic fiber based prints, and it was worth a try on my Canon printer. I found that it can achieve beautiful initial image quality from the Canon iPF5000 and its OEM Lucia pigmented ink set. Cost and availability aside, my desire to use this paper on a Canon printer then hinges not on initial image quality which is readily apparent, rather on image permanence which is now unknown. For obvious reasons, neither Canon nor Epson is ever likely to sponsor test results for a Canon iPF5000/Canon Lucia ink/Epson Exhibition Fiber combination. A big leap of faith must be made if the printmaker is to simply assume comparable longevity exists between the two different systems. One has to perform an aging experiment to know for sure! In this modern digital printing era, there are many, many interesting and useful combinations of equipment and supplies that fall into this orphan’s category for industry sponsored test results.
In the coming months, Aardenburg Imaging will begin to provide an accelerated light fastness testing service for more than just industry proffered combinations. AaI&A will strive to test products according to actual end-user preferences. Printmakers can be pretty creative when it comes to mixing and matching printers, inks, papers, and overcoats. The Aardenburg Assisted DIY (do-if-yourself) light fade testing program is soon to begin. AaI&A will move to a subscription model for funding (more about that in coming news items), and members will be able to contribute letter-size prints of a standardized AaI&A image target (the do-it-yourself part of the program). AaI&A will then conduct controlled light fading experiments and make the results available to our membership. The strength of this laboratory- assisted DIY approach is two-fold. First, Aardenburg will be able to tap into the abundance of materials and processes our members actually use. Second, the normal weakness of printmakers’ DIY testing is that the printmakers cannot easily compare their results to other studies due to lack of standardization. Pooling of DIY test data to build a comprehensive database for the printmakers’ community has never before been possible. The Aardenburg assisted DIY program will hopefully go a long way towards solving this problem.
Shown above is the image target that AaI&A members will be able to print using their normal printing practices on letter-size paper and mail to AaI&A for testing. It contains two color patch arrays. The smaller linear array is the 30 patch AaI standard color set (containing primarily the 24 reference colors belonging to the original Macbeth Colorchecker® target). This 30 patch target efficiently screens material longevity performance without taking up much real estate in accelerated aging equipment. It is great for testing lots of samples and quickly building a respectable database of information on basic product performance. The larger array contains tonal gradients in 12 hue planes of the CIELAB encoded colorspace. Each hue is extended across an L channel gradient from low chroma levels out to its high chroma boundaries as limited by the sRGB colorspace. Chroma peaks at the optimum L channel value for each hue. The larger array also contains an ample portion of graduated skintone and neutral/near neutral gray colors. The larger array thus provides more sophisticated color and tone analyses. AaI&A uses it to assess initial image reproduction quality with regard to color and tonal accuracy from digital file to print. It is also useful when more extensive longevity test results are of interest.
Thank you to all who donated to help make this project a reality. Aardenburg would not be able to provide essential industry insight without the generous participation of the Aardenburg Imaging Membership Community.
Mark H. McCormick-Goodhart
Director, Aardenburg Imaging and Archives