Scanning 50-Year-Old Ektachrome: Technical Observations on Personal Digital Archiving, Part 1
Of late I've been scanning a number of roughly 50-year-old family photographs that were originally shot with Kodak Ektachrome slide film. Most of these slides date from 1962 through 1968 and most employed flash lighting. It is my guess, based upon vague visual memories from the time, that they were most likely shot with an inexpensive Kodak Instamatic camera, probably a 104 with flashcubes. The Instamatics had slow shutter speeds, used poor quality, fixed-focus plastic lenses, but were able to take the then new Kodapak 126 cartridges loaded with film stock like Ektachrome and Kodachrome. The 126 magazine was a clever design that answered consumer complaints on the difficulties of loading and unloading regular roll film. With 126, you could just drop in the sealed cartridge and be up and running. Its asymmetrical design guaranteed that you couldn't load it wrong. Here is a great Kodak promo of the combination from the era. So, grooovy!
For both this family archive, mostly shot by my parents, and my own personal 35mm negative film archive from the 1980s-1990s, I use a relatively novel digital conversion workflow that employs an Epson Perfection V500 Photo Scanner, VueScan software, and linear DNG files imported into Adobe Lightroom. Generally speaking, here are some of the benefits that I see.
The Epson V500 is a great scanner for the money that uses contemporary LED lighting technology. LED is superior to the older Xenon gas cold cathode fluorescent lamps mainly because LED illumination is brighter and more even, which allows for the better extraction of a given film's shadow detail. With VueScan, you can choose among a number of film profiles to suit the media that you are scanning which is important for getting close to "good" color as a starting point. Absolute purists like medium and large format film artists who meticulously process one converted image at a time will argue for "raw" scans that simply capture the film as is (sometimes even including the IR channel data used in auto dust/scratch removal). Such raw scans are also possible with VueScan. However, when working with family photos in bulk quantities, this isn't a scalable option. In the particular case of my own color film days, 35mm negatives have an orange mask that needs to be accounted for through color-correction of some sort in order to realize good, baseline, positive color images. A VueScan film profile helps to get you there without a complicated trip through Photoshop.
A clarification... By "baseline" I mean something like "use-neutral." "Use-neutral" is a term borrowed from the more stringent realm of the FADGI Technical Guidelines that we follow in the University of Connecticut Libraries' digital still imaging lab that I manage. In the context of old family photos, I use the descriptor more in the narrative sense, without the inherent FADGI quality metrics strictly attached. So, what I'm aiming for with these old family shots are baseline positive images that can be archived as-is and that then require only minimal post-processing tweaks for web, print, etc. as needed. In essence, I want to be 90% of the way "there" as these images come off of the scanner.
Getting back to VueScan. Another one of its favorable attributes is its ability to create .DNG files direct from the scanner. Though these are, by virtue of scanner sensor design, linear (i.e. RGB-encoded vs. "raw" undemosaiced) and conform to the older DNG v.1.1 specification, the VueScan DNGs include the same basic embedded metadata tags as regular camera raw DNG files. This singular schema is useful once both camera DNGs and scanner DNGs occupy the same digital asset management ecosystem like a Lightroom catalog. In turn, most color/tone editing, descriptive metadata work such as Geo-referencing and keyword tagging, and final publishing (print or web) can mostly be done seamlessly under a single software roof for all of one's image archive. In seeing the identical embedded tags from a homogeneous DNG collection, Lightroom will present uniform slider labels and scales for options like white balance adjustments between both scanner and camera images. An additional scanner DNG attribute is that these files can be losslessly compressed according to the DNG specification's options. So, for the same data that is contained in an uncompressed TIF, you can also enjoy a smaller storage footprint. This is important particularly if one is scanning large volumes of images at a high sampling frequency, to a large color space, at 16 bit/channel.
More to come...