Weaving Images: Photographing Tapestries at the Gardner

The Gardner Museum has 38 tapestries in its collection, several of which need new imaging to meet contemporary museum preservation standards. A project to upgrade the lighting in the Gothic Room as part of the Museum's Strategic Plan in the fall of 2023, created a unique photography opportunity.

Isabella Stewart Gardner displayed two large tapestries in the Gothic Room, The Landlord and the Woodcutters and The Education of the Prince of Peace, both in need of new photography. A third tapestry from the nearby Third Floor Stairhall, Esther Fainting before Ahasuerus, was also included in this project. Planning for the photography of such large textiles took over a year and involved researching equipment and techniques, building a bespoke apparatus to hold the camera and lights, and extensive logistical planning for safely moving the tapestries from the wall to the floor.

History of Digital Camera Technology

The concept of a digital camera was first explored in 1975 by Eastman Kodak. The first model constructed by Steven Sasson, which was referred to as the toaster, weighed in at nearly 8lbs, captured .01 megapixel, stored to a digital cassette tape, and had no ability to capture color. Today, we are fortunate to have cameras under 2 lbs, the ability to capture up to 150 megapixels in full color, and the ability to directly shoot to a computer with a tethered live view. It is amazing how camera technology has revolutionized cultural heritage imaging in just 50 years.

Challenges to Photographing Tapestries

A fascinating resource used in preparation for this project was an article about a similar project at the Met in 1998, in which photographers were tasked with photographing the museum's Hunt of the Unicorn tapestries¹. Numerous challenges included the setup of the tapestries, construction of a camera apparatus that would be parallel to the surface of the tapestry, and the processing of data to create the final images. Back then, as is the case today, to create high resolution photography of large objects requires a process called "stitching." This involves capturing multiple images of small portions of the object, called “tiles,”  and then stitching them together using computer software. Unfortunately technology had not advanced far enough at that time for the Met photographers to successfully create complete images of the tapestries. After inputting their data into a supercomputer, the end results still showed misaligned pixels: the tiles did not line up.

Despite today's camera technology and image quality, we still encounter similar challenges that the Met faced 26 years ago. Although our eyes see a tapestry as a flat textile, it is actually thousands of interlocking threads that hold memory based on their shape. When a thread holds so much memory, it can be a challenge to ask it to change its shape. The camera can see micro movements in each thread as it relaxes. The camera attempts to record these threads with as little movement as possible so that each tile image can find the exact thread from an adjacent image and digitally stitch them together. 

One way to stabilize the threads is to allow the tapestry to relax after it is laid flat and to reduce vibrations on the floor. The tight timeline in which all three of our tapestries needed to be photographed did not allow for this gradual relaxation though.   

Modern technology came to the rescue. Each frame was captured with a 40% overlay from the previous frame. Using the stitching software PTGui, each frame is able to find similar pixels within the 40% overlay and stitches an overall image of the tapestry. Control points within the software were then used by the photographer to manually pinpoint pixels to tell the software where it should look for similar pixels. The end result for a single tapestry was over 45 frames, over 10gb of data, and weeks of manually directing the software how to stitch threads together.

Photography Setup

The camera set up was a crucial component in capturing the tiles for each tapestry. We considered gradually shifting the tapestry under the camera and keeping the camera stationary, but since each fiber had to stay consistent and still, this was not feasible. We also considered leaving the tapestries hanging and photographing them vertically, as had been done in earlier photography campaigns. But this was also not feasible, as the tapestry does not hang flat and moves with the slightest air flow. Ultimately we chose to lay the tapestry flat on the floor and move the camera and lights over it. A 20' steel bridge was constructed and mounted on two rolling tripods with a pulley system to move the camera and lights on a track.

Key to this setup was establishing a grid to keep frames consistent and to ensure a parallel plane is maintained; thankfully, we had a built-in grid in the tiled floor. In order to keep a parallel plane and to ensure best focus, a small threaded mirror with a hole in the middle called a ZigAlign was attached to the lens. As the camera points down to the surface, another mirror is placed filling the frame, and the camera's x and y axes are adjusted until the mirror shows an aligned bullseye. The camera's alignment position is now within the optimal focus plane, and we were ready to capture our tapestries. 
 

Why We Photograph

Besides creating beautiful images, what more can photography do for us? High quality photography gives the viewer intimate insight into an object's structure, materiality, and history that is not always apparent to the naked eye, maximizing accessibility to the collection while minimizing the need to move fragile artworks. Photography also contributes to preservation efforts, as it allows our conservation team to monitor an object's condition over time, which can inform future treatment approaches. At the Gardner we continually strive to make our collection accessible for the education and enjoyment of the public forever, and that includes utilizing and adapting new technology as demonstrated in this project. 

 ¹Preston, Richard. “Capturing the Unicorn.” The New Yorker, April 4, 2005. https://www.newyorker.com/magazine/2005/04/11/capturing-the-unicorn. Accessed 18 October 2024.