Objects and Treatments

Ready For Our Close Up!

Documentation is an important part of a conservator’s job. This ranges from ensuring all artifacts have been properly delivered, to writing down everything that we do regarding the object, to photography. It is essential that anyone who comes upon the object post conservation is able to understand what has been done and why, and see evidence of the object before it was touched.

You can imagine how tempting it is just to poke at an artifact here and there to test the density or porosity, or to pick at those crispy bits of old adhesive. This is something that I find a lot of students in the lab are struggling with as they study their new objects. The problem with poking and prodding the artifact is that you have to make sure you have taken a photograph of what the object looked like before it has undergone any treatment. That includes the occasional test poke that might potentially cause a piece to flake off or crumble.

9363-00-1     9363-00-2

Before and After photographs of a Victorian coin from the Brecknock Museum in Powys

Fortunately, we have access to a photography lab where we are able to borrow Nikon or Pentax cameras and shoot professional photographs with proper lighting. We have a range of lighting at our disposal: LED, Fluorescent, or Ultra Violet (UV). LEDs give off less heat and less Ultraviolet light than Fluorescent lighting, which can be important if your artifact is temperature and UV sensitive. Fluorescent lighting tends to cause softer edges and shadows. Different light sources also have different color temperatures and different effects on how we perceive colors.  UV lighting is used to show previous adhesives or markings that might have been placed on an artifact.

Occasionally, we have objects that are too large to transport to the photography lab, such as our sarcophagus, whose lid is being prepared for cleaning and repairs. This week’s challenge was to take a proper “before” photo of the inside of the sarcophagus lid with good lighting across its entire length.

The team initially attempted to leave the sarcophagus on the table where it has made its home and take photos from above. Using LED lights, four photos were taken of different parts of the lid as, even at ceiling height, the camera could not capture a full image of the lid. From there they attempted to overlay the photos in Photoshop with a method called “stitching.” Unfortunately, this method did not work out, as the photos were taken at slightly different distances from the object and did not line up.

the-first-attempt

With photographing such a large object, the main struggle is that the camera lens can only take in so much of an image at a specific height. So on Monday, in an attempt to counter this, the team carefully brought the sarcophagus lid down to the floor (with reinforcements from the lab for extra safety) and brought all of the photography equipment upstairs again. The camera was still not far enough from the lid to capture the full image, so the boom stand was put on a short table to increase its height.

bracing-the-boom

Another problem arose when it was agreed that the foot of the lid was still far too dark in photos to see details with just the two LED light panels, so a third overhead light was brought up. This improved the evenness of the lighting, although it caused issues with brightness levels and focus, which were ultimately improved by setting the light up across from the camera rather than behind it. Small adjustments can make a big difference!

floor-photo

The team of four took a few types of photographs so that if one did not work there would be other options: it would not be ideal to have to move the sarcophagus lid once again if not necessary! The first type was a straight over head full length shot. These photos looked good on the camera screen but when zoomed in on the computer, the focus was a little too blurry for satisfaction despite adjustments to ISO (sensitivity to incoming light) and aperture (depth of field). The second method was to take 3 photos of the lid to be stitched together, but keeping the camera in the same place and only rotating the camera angle. This could cause potential bending of the artifacts in the images. The third was again 3 images to be stitched, but the camera faced straight down each time and was moved along a line of tape on the floor to ensure as much similarity as possible in the photos. The potential problem is that head of the sarcophagus lid was a little higher than the feet and that would change the focus on the camera.

looking-up

Ultimately, the full sarcophagus photo was deemed satisfactory for treatment documentation, with the stitched photos to look at specific areas in more detail. Photographs are currently still in production but here is a sneak peak of the current status:

 

sarcophagus

Photo courtesy of Chloe Pearce

 

As the treatment of the sarcophagus lid progresses, we will post updates letting you know how it is going. Until then, please feel free to ask questions!

 

All photos not already noted courtesy of Stephanie Whitehead

Comments

  • JP Brown

    You guys should look at using photogrammetry and orthorectified images — much better results that stitching in Photoshop.

Share your thoughts with us!