You may recall back in September of 2018 when we shared an article I had written in our UC Libraries’ newsletter about photographic documentation in the Lab and a recent workshop I had attended through FAIC: http://libapps.libraries.uc.edu/source/photo-documentation-in-the-preservation-lab/  If you missed it, basically the workshop focused on a standardized and replicable UV/visible fluorescence documentation workflow, and was taught by Conservator Jennifer McGlinchey Sexton at Duke University.  It was a fantastic workshop and I came back from it with a plan for a new UV workflow and a list of equipment for an improved UV setup.  However, conservation photography equipment can be pricey, especially when you are embarking on improving a very specialized setup, like UV.  On top of that we had just included a Near Infrared workflow into our photography repertoire and our budget was feeling the strain.  So we took the smart approach and slowly bought equipment, here and there, when the budget allowed.  Finally, we now have all the equipment we need for the new setup.  Check out the results from today’s session:

Lucky for me, when it came to refreshing myself on the actual workflow I had learned at Duke the binder that Jennifer had put together for each workshop participant was incredibly thorough and all I needed to replicate the workflow in the Lab.  Before we dive into the aspects of the new workflow and why it is “improved”, let’s discuss our previous workflow for a second.  Like most conservation labs, we refer to The AIC Guide to Digital Photography and Conservation Documentation (currently on sale for $20!) for almost anything PhotoDoc-related.  For UV, the book details the different types of ultraviolet radiation, various types of UV lamps, safety (both for the object and yourself), setup, filters, and workflow.  In this volume the basic workflow describes using the camera’s “shade” white balance setting and then adjusting the temperature to 10000K and the tint to +35 in CameraRaw.  Exposure is determined by the photographer using visual cues alone, as there is no way to white balance using a standard color checker; the Neutral 8 (N8) patch will no longer be neutral grey under UV fluorescence. 

While this workflow produces very usable images that illustrate the fluorescence of materials, inks, pigments, adhesive and staining, it is subjective and makes replication of results more difficult. While our prior workflow for UV photography could use improvement, the workflow itself was not the main issue, in fact, this is the workflow used in many other labs.  The problem child of our setup was the equipment, and I’m sure any lab trying to piece together a completely brand new PhotoDoc studio (which happened six years ago for us) on a budget can relate.  Behold our previous “UV” lamps, which I affectionately referred to as the “Home Depot setup”:

If we’re being honest, these low-pressure fluorescent lamps were super cheap and served their purpose for 6 years.  Shooting with them was a bear; since the intensity was very weak, I would have to shoot with both lamps and we did not have any clamps to hold them in place. I had to either get someone to assist me or, once I got a wireless mouse, I got even more creative (ask me about it sometime – it’s pretty funny).  The downside of these inexpensive lamps is the significant and noticeable visible light leakage.  Since the fluorescent tubes are not properly filtered, the image you are left with has a blueish-purple cast to it:

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Now onto the new setup!  The main components include:

• 1 – REL C4 Magnum-GO lamp* – this is an LED lamp with a peak output of 368nm.  It comes with a filter over the radiation source, therefore eliminating visible light leakage from the lamp.
• Taget UV and UV Gray Card – this color checker and gray card are specially designed for UVA fluorescence photography and allow you to white balance prior to imaging (gray card) and identify the RGB values (target). 
• Impact Super Clamp – to hold lamp for hands-free tethered imaging
• Filters (which you should have regardless of your setup, but we did not have them previously) –
  •  2E – cuts UV and blue
  • PECA 918 (or equivalent, we have a Hoya IR Cut filter) – cuts IR even more
  • We also purchased an adapter in order to fit both filters on our smaller 50mm lens
• UV Glasses (always part of our setup but worth mentioning) – safety is very important and we purchased these goggles because they easily fit over eyeglasses.

Fun facts about the REL lamp: The intensity of the lamp and the handle make it great for quick examination.  It has a normal LED built in as well and you can have both functions on at the same time, making it easier to see if you’ve turned your studio lights off or if you want to do a quick comparison of normal illumination vs UV radiation.  As with any UV radiation source you want to keep it away from your object until you are ready to image.  When using a radiation source you also want to let the lamp warm up for at least one minute before imaging (away from the object or with the object covered).  This is because when a lamp is initially turned on it can emit up to eight times more UV radiation, and allowing the lamp to warm up gives the output levels a chance to even out, making it much safer for the object.

Fun facts about the Target UV & UV Gray Card: I know the target and gray card are extremely expensive and not feasible for everyone, but there are definitely advantages to them if you have the budget to invest in the pair.  Not only do the target and gray card allow for white balancing, thus giving you a more accurate color temperature and color representation, but the target is also double-sided and has 4 separate intensity levels: low, medium, high and ultra.  This basically means that you can image a wider variety of fluorescence intensities without sacrificing exposure or color representation.  For example, if you have an object with a layer of varnish on it that only mildly fluoresces, you would probably use the “low” intensity patch to white balance, whereas if you have an object with optical brighteners (extreme fluorescence), you would likely use the “ultra” intensity scale.  This makes it very handy if you have one object that has multiple materials/inscriptions/staining that are fluorescing at very different intensities.

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Overall, I am very happy with the new setup and workflow, and I am looking forward to using it more and more in the future.

*In the workshop we used by the REL C4 Magnum LED lamps and these UV Systems SuperBright 3 LW370 lamps.  Both worked beautifully but it seemed as though two of the UV Systems lamps would be needed while I could get away with just purchasing one of the REL LED lamps.  The UV Systems lamps would have also required a much more robust mounting system beyond the SuperClamp because of their weight and orientation.

Jessica Ebert [UCL] – Conservation Tech/Photographic Documentation Tech