Tag Archives: Fun with PhotoDoc

Fun with PhotoDoc: Multispectral Imaging with MISHA (Edition 13)

As mentioned in a previous blog post, Andrew and Naomi from Case Western Reserve came to the lab in late February to demo the MISHA portable multispectral imaging system, made possible by a National Endowment for the Humanities (NEH) Research Grant awarded to the Rochester Institute of Technology. In total, Naomi and Andrew imaged five objects from the Public Library, UC Libraries, and one of our third-party institutional clients. Imaged books included, one Otto Ege item, two Book of Hours, one undated Latin music manuscript, and a Pentateuch volume from Hebrew Union College. In all, thirteen separate capture sessions were carried out for the five objects. Afterwards, the raw data from the capture sessions was shared with the Lab via OSF (Open Science Framework) so that I could process the data in the NEH grant supported open access RCHIVE (Rochester Cultural Heritage Image processing and Visualization Environment) software.

The image gallery above shows the recto of leaf 32 from the Public Library’s copy of Fifty Original Leaves from Medieval Manuscripts, Western Europe, XII-XVI century, by Otto Ege.

While each of the capture sessions took only two minutes to complete, I found that processing the raw data took me a bit longer to figure out. Processing the data felt very similar to using CHI’s RTI Builder and Viewer software. However, in this situation I did not have a week-long training opportunity to learn the ins and outs of the software and its functions. For the Spectral Analysis App, I had only a couple of brief documents to refer to, so the learning curve was a little steeper. I also experienced some issues with the software while processing the data with the flatfield files provided from the capture session. But in the end, the processed files seemed fine without the flatfield data, so it all worked out.

RGB image of a parchment page from a Pentateuch volume belonging to Hebrew Union College — RGB representation

Multispectral image of a parchment page from a Pentateuch volume belonging to Hebrew Union College — RGB representation

The above image gallery depicts a leaf from Hebrew Union College’s Pentateuch Ms. 1 with adhesive staining, tape, and prior repairs.

What I discovered through processing all the MISHA data and then comparing it to the existing specialized imaging done in the Lab was that the suite of imaging we do in the Lab is very well rounded and, in general, suits our needs and our clientele quite well. In many cases, our results were at least comparable, if not better (specifically within the UV wavelengths) than the results accomplished using the MISHA. And, especially with our UV workflow, though our current capture time might be slightly longer than that of MISHA, the data processing time is significantly shorter and, in the case of UV especially, the side-by-side results of the accurate normal illumination next to the full color UV image(s) is ideal for our purposes.

RGB image of an opening of a Book of Hours with scraped parchment and illegible text — RGB representation

Multispectral image of an opening of a Book of Hours with scraped parchment and illegible text — RGB representation

The images above show an example of scraped text on parchment from UC Libraries Hours of the Virgin from 1475, currently in the Lab for treatment. Compare these MISHA generated images to the documentation performed by Catarina Figueirinhas and myself using the Lab’s equipment and processes below.

Normal illumination image of the same illegible text — Normal illumination

UV image of the same illegible text — Normal illumination

That said, I am fully aware that not everyone has access to the equipment/training that I have been fortunate to curate/experience over the last five plus years. Also, not everyone uses their finished data exactly how we do. For instance, the needs and expectations of a conservation lab and cultural heritage institutions can be very different. Even within the conservation field, how we use the data provided by specialized imaging in our hybrid book and paper lab is quite different from the kind of data needed by a fine arts conservation lab. Ultimately, I think the core audience for a system like the MISHA system is an organization looking to expand their suite of imaging services, or an institution with no multispectral imaging infrastructure interested in imaging collections in a quick and easy manner. Though for the latter, I would say that there is a big learning curve in manipulating and processing the data, but if greater focus is put into making the software and processing steps user-friendly, especially to novice users, it is completely manageable. And if this step is taken, I think the system could help a lot of institutions dive deeper into the materiality and history of their collections.

The images above depict another example of faded, scraped text. This flyleaf is from an undated Latin music manuscript that is part of the Public Library’s collection. The images below represent imaging done by the Lab, both normal illumination and UV radiation, with the goal to increase the legibility of the inscription.

Normal illumination image of faded text from a parchment manuscript — Normal illumination

UV image of faded text from a parchment manuscript — Normal illumination

In the end, multispectral imaging is just plain FUN! So, the idea of making it more accessible to a wider audience is extremely exciting and I think the work that NEH, RIT, and colleagues like Andrew and Naomi are doing to share the power and wonder of multispectral imaging is amazing. The idea of a portable multispectral imaging system with free processing software that does not take a PhD to use is boundary-breaking, and it gives us a glimpse into a future of accessible and exciting imaging, which thus allows us to see and understand more of the past. I will always be an advocate for that kind of imaging!

Jessica Ebert [UCL] – Sr. Conservation & Photographic Documentation Specialist

Fun with PhotoDoc: Collaborative RTI (Edition 12)

One of the exciting things about the Preservation Lab is you never know what’s going to come into the Lab next! Sure, sometimes we know a little bit ahead of time about upcoming projects, but usually the special collections intake meetings are filled with “oohh’s”, “aahh’s” and sometimes “oh no’s”. But it’s not very often that you get to work on a project, here in Cincinnati, while the objects themselves are across the Atlantic. Combine that with RTI (Reflectance Transformation Imaging), a variety of Vesalius related texts, and an opportunity to collaborate with other photographers, and you’ve got a recipe for one exciting project!

Currently in the planning stages, the Winkler Center for the History of the Health Professions will host a series of Cecil Striker lectures and a physical exhibition that will celebrate the work of Andreas Vesalius. The series and exhibition is entitled The Illustrated Human: the Impact of Andreas Vesalius and is sponsored by Stephen and Sandra Joffe. Vesalius was a renowned 16^th century author and physician, whose iconic work on human anatomy, De Humani Corporis Fabrica Libri Septem, is considered one of the most influential anatomy books ever written. Three rare first edition Vesalius volumes will be exhibited during this upcoming lecture series, gratuitously on loan from Stephen and Sandra Joffe. Dr. Joffe is a long-time UC supporter and an emeritus faculty member.

For the upcoming exhibit, the Lab will be creating custom supports, as needed, to display the volumes, and providing imaging of various pages and illustrations for promotion. I will also be doing any additional specialized imaging that might be helpful.

Since we believe that some, if not all three bindings coming to Cincinnati, might be original to the volumes, and we immediately thought of RTI and wondered if it could provide new insights to researchers. After seeing the wonders of RTI, via RTI examples from the Lab, the owners of the Vesalius editions were interested in having RTI done on a selection of Vesalius items in their collection, including some that wouldn’t be coming to the Lab. The only hitch? The volumes are at their home in Scotland. The solution: hire a local photographer, Iain McLean, to carry out the capture portion of the RTI in Scotland, and have the files shared with the Lab for processing and rendering. Though Iain is an established commercial photographer with a digital imaging background, RTI was a new adventure for him, so I shared some resources with him, including CHI’s Guide to Highlight Image Capture and some notes and resources created by the Lab during our various capture sessions. Iain and I then met via Zoom in mid- August to discuss the ins and outs of RTI highlight capture prior to his capture session on August 20^th. Iain also brought his colleague and fellow photographer, John Linton, into the fold to assist him during the capture session, which I recommended highly because though it might be possible to do RTI solo, I can’t imagine a capture session without my normal collaborator and the Lab’s Assistant Conservator, Catarina Figueirinhas. The session would take double the time and I’d make five times the mistakes without Cat! (Check out a time lapse video of Cat and I doing RTI in the Lab on our YouTube channel).

Image of Iain and John carrying out the RTI capture session in Dunderave castle. — Iain and John during the capture session, featuring one of my favorite volumes that they captured that day. (This image was taken by Iain and kindly shared with me.)

After a successful test capture session, Iain and John were ready for the main capture session on August 20^th. They ended up capturing the front and back covers of seven volumes. Once the massive capture session was completed, Iain shared the jpegs with me so that I could begin processing the images in RTI Builder and then rendering the snapshots in RTI Viewer.

This is a time lapse video of the capture session. (This video was created by Iain and kindly shared with me.)

After processing the 679 images and rendering the snapshots, here are some of my favorite finds:

This is a composite of two RTI generated images. The left shows the default mode, and the right specular enhancement. — This a side-by-side of an upper cover. The left image shows the default lighting mode in RTI Viewer and the right show the specular enhancement mode. On the right, just above the center panel, you can see the letters GFV (above the panel) and 1567 (below the panel), which are much more visible with the specular enhancement mode than under normal illumination.

This is a composite of three RTI generated images. The left is the default mode, the center is Normals Visual mode and the right is specular enhancement mode. — Here you can see a detailed composite of another cover’s center panel. On the left is the default/normal illumination mode, the center shows the normals visualization mode, and the right is the specular enhancement mode. You can see by employing the two specialized RTI modes the ornate detail of the cover is far more readable.

This is a composite of two RTI generated images, diffuse gain mode and default mode. — This composite of the upper cover features the diffuse gain mode on the upper left half, and the default lighting mode on the lower left half. The diffuse gain mode really accentuates the features of the man in the center panel.

This is a composite of two RTI generated images, default mode and specular enhancement mode. — This composite of the upper cover features the diffuse gain mode on the upper left half, and the default lighting mode on the lower left half. The diffuse gain mode really accentuates the features of the man in the center panel.

This is a composite of two RTI generated images, default mode on the left and specular enhancement mode on the right. — This composite of another upper cover shows the default mode on the left and the specular enhancement mode on the right. With this one, the discoloration of the cover distracts the eye and pulls it away from the detail of the decoration, but with the specular enhancement mode you can eliminate the color completely and modify the secularity so that your eye can focus solely on the elaborate detail.

This was such a fun experience for me, and I really enjoyed collaborating with colleagues outside the conservation field and across the pond! And I look forward to the condition photography of the three volumes and any additional specialized photography that might be helpful.

Special thank you to Stephen and Sandra Joffe for allowing their important collection items to be photographed, and for giving the Lab full permission to use the generated images. Also, a very special thanks to photographers Iain McLean and John Linton for capturing these covers and for collaborating with me on this exciting project.

Jessica Ebert [UCL] – Sr. Conservation & Photographic Documentation Specialist

Fun with PhotoDoc: New and Improved UV Setup

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:

Left: normal illumination, Right: UV radiation

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”:

Good ole black lights! Though, unfortunately, we did not have a velvet Elvis black light poster hanging in the studio to really take full advantage of these babies.

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:

Notice the blue cast to the background in this image.

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.

Right to left, top to bottom: filters, SuperClamp, UV Glasses, Target UV, UV Gray Card, REL lamp

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.

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

Fun with PhotoDoc (Edition 10)

Since it’s Tuesday, but you’re probably wishing it was Friday, I thought I’d share some fun gifs of a 16th century German ophthalmolgy book from UC’s Archives & Rare Books Library that was recently treated and returned. But first, let’s take a look at the treatment carried out by our conservator, Ashleigh Schieszer.

This full vellum binding suffered the same fate as many other stiff board vellum bindings: significantly warped boards, a result of fluctuations in humidity. The volume arrived in the lab with vellum losses along the head and tail of the spine. There was also evidence of two ties at the fore edge that would have originally been used to keep the boards from warping, however, all but a small fragment of these ties were lost. Ashleigh humidified and flattened the upper and lower boards and added new alum-tawed ties sympathetic to the placement and size of the original ties. The binding was then housed in a cloth covered compression clamshell (created by our box-making magician, Chris) to help keep the boards from warping in the future.

Here you can see the fragment of the original tie with the new tie inserted below it.

Now onto the gifs. This volume has several anatomical flap prints that explore the inner working of the eye. Here are two of the flap prints, one which takes a look at the brain from above and another that examines the eye from the side:

We were in luck that these particular anatomical flap prints were in relatively good condition when they came to the lab. However, that is usually not the case with these very fragile multi-component prints. If you are interested in the learning more about the history, treatment and exhibition of these prints, check out Meg Brown’s article “Flip, Flap and Crack”.
Jessica Ebert [UCL] – Conservation Tech/Photographic Documentation Tech

Fun with PhotoDoc – In the News (Edition 9)

Check out this new article written by our lead photographic documentation technician, Jessica Ebert, on the exciting world of photographic documentation in the Preservation Lab: http://libapps.libraries.uc.edu/source/photo-documentation-in-the-preservation-lab/

This is an image of a painting of a young woman done in a variety of white pigments. The image depicts the painting under ultraviolet radiation. This particular painting was painted by the artist under UV radiation, so it is not until it exposed to UV radiation that the viewer is able to see the full extent of the detailed work.

This is an example of one of the pieces that was photographed under UV radiation in a recent workshop Jessica attended through AIC. In this workshop at Duke University, taught by conservator Jennifer McGlinchey Sexton, participants learned how to identify the best UV lamps for conservation documentation, how to test for visible light leakage, and how to standardize UV documentation workflow using the Target UV (to the right of the painting).

Fun with PhotoDoc: Infrared Again (Edition 8)

It’s been a while since my last Fun with PhotoDoc post, so I wanted to share some progress I’ve been making with Reflected IR. You might remember from my last PhotoDoc post, we purchased a modified UV-Vis-IR camera from MaxMax at the end of 2017. Our first two objects we (Ashleigh and I) examined and documented with the camera were a great learning experience, but didn’t exactly leave me with goosebumps. Still it was a good experience and we worked out the use of the various filters and the general IR workflow.
Fast forward to April when the lab received not one but two books from UC in need of IR photography. The first was the Masters thesis of Ralph E Oesper from the Oesper History of Chemistry collection. The curator wished to exhibit several of the pages from the volume, but upon inspection Ashleigh (our conservator) was concerned that the purple text ink might be dye based, which is very light sensitive.

: Normal illumination image

: Near infrared image

The ink disappearing under near IR is a clear indicator that the ink is most likely dye based, and while that made Ashleigh very happy and validated her choice to create printed surrogates of the pages for exhibition, I still felt a little less than wow’d. I was still waiting for a really compelling and dramatic IR example.
Enter volume 1 from the Third German Protestant Church of Cincinnati collection, an 18 volume collection of early Cincinnati baptismal, marriage, and funeral records from the Archives and Rare Books Library that pre-dates the city records. In this case, Ashleigh wanted me to examine and document 4 pages within the volume with faint graphite inscriptions on paper with heavy foxing.

Side by side comparison of one page under normal illumination and near infrared

Finally! A satisfying IR session with helpful results. Documenting all four pages using reflected IR allows for the foxing to disappear from the page, thus making the faint graphite inscription easier to read. After converting the IR image to grayscale I also upped the contrast significantly, allowing for better readability of the handwriting. In the end, we now have four pages of legible inscriptions and I’m very happy with the results.

Click on an individual image to see the gif in action for that page…

I definitely still have a lot to learn when it comes to near infrared photography, but I would call this, not only a satisfying experience, but progress that will hopefully lead to a better workflow. This round of IR photography definitely was not seamless, but I did learn more, as I do every time I shoot, and it is my hope that the more I do the more I will streamline and improve our IR workflow.

Jessica Ebert (UCL) – Conservation Technician, Lead Photographic Documentation Tech

Fun with PhotoDoc: Infrared (Edition 7)

At the end of last year the lab purchased a modified UV-Vis-IR Nikon through MaxMax so that we can start to play around with infrared photography. Infrared photography (IR) is commonly used in fine art conservation as an examination tool. Reflected IR can be helpful when trying to identify pigments, inks, coatings, etc. and transmitted IR can helpful for viewing watermarks, underdrawings, and linings. We’ve only just started dabbling with IR photography, but I wanted to share some photos from my most recent session with reflected IR.

This is a full leather photo album from the Public Library of Cincinnati & Hamilton County’s collection. This early 1900s photo album contains hand-colored silver gelatin photographs taken by A. Nielen. The photographs appear to depict his travels through the US and Canada, and various landmarks and neighborhoods of Cincinnati are represented.

: Before treatment

: After treatment

This seemed like a good object for reflected IR because of the hand-coloring on the photographs and the white ink inscription below each photograph. I began by taking a representative visible light image (first image below) using our modified UV-Vis-IR camera, incandescent lighting, and the X-Nite CC1 filter on our 50mm lens. Then, being careful not to move the position of the camera or the object, I switched to the X-Nite 830 filter (830nm) and converted that image to grayscale in Photoshop (second image below). Then I took my visible light image and my reflected IR image into Photoshop to create the false-color image (third image below). The digital false-color image is a combined representation of the visible and infrared images, and it’s actually quite simple to make. You basically copy and paste the various channels for the VIS and IR image as follows, green to blue, red to green, and IR to red. The false-color image allows you to better differentiate and characterize the various materials (pigments, inks, etc.) and potentially even identify them if you have sufficient known samples to use as references.

: Normal illumination

: Near infrared with wavelength at roughly 830nm

: False color

Like I said, we’ve only just started using IR and we’ve got a long way to go, but I’m looking forward to experimenting and learning more about it as time goes on.

Jessica Ebert (UCL) – Conservation Technician & Photographic Documentation Tech

Fun with PhotoDoc – RTI Viewer Video (Edition 6)

In my last “Fun with PhotoDoc” post I discussed the my recent RTI training with Cultural Heritage Imaging at Yale University. If you missed that post you can check it out here. In that post I discussed our first RTI capture session on a book entitled, Aller Bücher und Schrifften des thewren, seligen Mans Gottes Doct. Mart. Lutheri …, which is part UC’s Archives & Rare Books Library’s collection and is the eighth volume in an eight volume set. The binding is most likely age-hardened alum-tawed leather (though possibly vellum) on wooden boards with embossed paneled decoration that is barely visible under normal illumination. In that first RTI blog post I shared some snapshots of the various RTI modes you can explore within the RTI Viewer software, but I knew that I ultimately wanted to create a video capture of the RTI Viewer in action. I was finally able to do that using a free software called TinyTake.

This video can also be viewed through UCL Media Space: https://stream.libraries.uc.edu/media/AllerBucherUndSchrifften_i17632730_VideoCaptureRTI/1_s13c9opc
In this video we explore the following modes built within the RTI Viewer as the light position is moved around the object:

Default Mode (HSH)
Specular Enhancement Mode with color removed (HSH) – notice the “1571” inscription that becomes more apparent. This volume was printed in 1568, and we believe that 1571 was when the publication was bound.
Normals Visualization Mode (HSH) – allows the human eye to better determine is convex and concave on the surface of the cover.
Diffuse Gain Mode (PTM) – This mode is ideal for visualizing surface abrasions and losses. Take notice of the “ID” inscription that becomes more visible, and when we switch back to the default mode you can see that this “ID” inscription is virtually invisible to the naked eye.

I have to say, Catarina and I really enjoyed the capture process for this binding, but when we found that “ID” and then looked at the physical binding and could barely see anything…we were kind of giddy! I’m hoping to create more RTI Viewer video captures like this as we carry out more RTI capture sessions for collection materials. When I do, I will make sure to share them here.
Jessica Ebert (UCL) – Conservation Technician

Fun with PhotoDoc – RTI (Edition 5)

At the beginning of April I was lucky enough to attend a RTI (Reflectance Transformation Imaging) workshop offered by Cultural Heritage Imaging (CHI) at Yale University. CHI is a non-profit organization that shares and teaches RTI and Photogrammetry technology with cultural heritage institutions around the world. The class I attended was a 4-day NEH grant sponsored course taught by three RTI experts from CHI, and it was amazing!

This is a composite image of all the highlight points from one RTI section. The software uses these highlight points to map the surface shape and color of your object.

So, what is RTI? CHI describes it on their website as “a computational photographic method that captures a subject’s surface shape and color and enables the interactive re-lighting of the subject from any direction”. For highlight RTI, which is the least expensive and most accessible method for most institutions and what I was taught in the class, you basically take a series of 36 to 48 images of an object where everything is constant (settings and position of objects, camera and spheres) except for the light position. With a reflective black sphere (or 2) set up next to your object, you move you light source around the object at varying angles. Then, you take that set of images and plug them into the free RTI software provided by CHI and the algorithm detects the sphere(s) and the highlight points (from your light) captured on the sphere(s) and voila!…you have an fun and interactive way to look at your object’s surface texture.
Before I attended this fantastic training opportunity, our conservator and I knew right away what the subject of our first capture would be when I returned…a 16th century German Reformation text by Martin Luther with a highly decorated cover that is practically invisible under normal illumination.

Here’s a time lapse video of our first (and second) capture in the Lab…
That day (Tuesday) were were able to capture the upper and lower covers of the Reformation text (from ARB), the original silk cover from a 17th century Chinese manuscript (from Hebrew Union College) and an illuminated page from a German vellum prayer book (from PLCH). And here our some snapshots of our results from two of those captures (click on the thumbnails for a larger view of the image)…

This possibly 13th century German Prayer Book has a full stiff vellum binding and an illuminated first page. The varying modes highlight condition issues like worn/abraded parchment and flaking gold illumination, as well as the overall surface texture of the illumination.

I hope you’ve enjoyed getting a little sneak peek into RTI. I will be demoing and discussing in further depth this afternoon from 1:30 to 3pm at the Lab’s annual Preservation Week Open House. I also hope to do more RTI captures/processes in the future and share them here.
Jessica Ebert (UCL) – Conservation Technician

Fun with PhotoDoc – Edition 4

The amazing enclosure made by our very own conservation technician, Chris Voynovich, for volume 1 of the W.S. Porter Collection.

We very recently returned a two volume collection of photographs taken by William S. Porter, known as the W.S. Porter Collection, to the Public Library. William S. Porter is known in Cincinnati as one of the two photographers responsible for the 1848 Cincinnati Panorama (you can read more about and even explore this amazing daguerreotype panorama here). Volume one of the collection consists of 7 cased photographs (including daguerreotypes, ambrotypes, and tintypes) and 1 non-cased tintype, all reportedly taken by W.S. Porter, while volume 2 consists of one framed daguerreotype of W.S. Porter and a preservation print of that photograph. When these photographs arrived in the Lab for treatment, many of the cases were damaged (especially along the spine – some broken completely, one previously “repaired” with tape, etc.), the framed photograph needed re-packaging, and the collection needed two custom enclosures (vol. 1 & 2) to safely store all the photographs.

(Left) Before “bench” photos of one of the cased photographs labeled “John Wesley Lever”, (Right) After photos of the mended case.

Now, as anyone who does photographic documentation will tell you, taking treatment documentation photos of photographs is a pain, especially on the copy stand (i.e. from above) and especially when you were trained in-house in a book and paper lab. Glass objects just aren’t as common around these parts. During PhotoDoc glass just acts as a mirror, reflecting all your light and even your camera lens and obstructing the actual photograph you are trying to capture. But we knew that we wanted some good quality photos of the photographs to print as surrogates and to also use in the enclosures. Black foam core and an Olfa rotary cutter to the rescue! Using these two supplies I created a non-reflective black surface to place around the camera lens to help reduce reflections and absorb light.

In order to mount this black foam core on the camera lens I measured the diameter of our lens and the distance from the edge of the lens to the neck of the copy stand when the camera was in place.

The foam core allows enough flexibility for the deflector to just slide past the UV filter and snap into place securely.

With the black non-reflective board in place, I was able, with guidance from our conservator, to get some pretty good shots of the photographs to be used as surrogates. The photos were also printed out and attached to the back of individual tuxedo boxes for each cased photograph. Instructions to “store face down” were placed on the front of each tuxedo box to assist patrons in proper storage. (The glass on all of these photographs is degraded and if stored face up the glass can actually weep onto the photograph causing significant damage, therefore cased daguerreotypes/ambrotypes/tintypes are generally stored up-side-down to prevent further damage to the actual photograph). All of the tuxedo boxes for volume 1 were housed within a two-tiered clamshell box with two removable trays made by our resident “Box Master”, Chris Voynovich. It should be noted that it’s a miracle this enclosure made it out of the lab and back to the Public Library, because several staff members were so enamored with it and thought it would make the best jewelry box! I mean, it kind of would, wouldn’t it?
Here are the images I was able to obtain using my homemade non-reflective board:

Jessica Ebert (UCL) – Conservation Technician