Some of the most spectacular items in the NYC Municipal Archives are the 3,200 drawings in the Department of Parks & Recreation collection. Of these, 1,500 are related to the design and construction of Central Park and will be the basis of the Municipal Archives’ new book The Central Park: Original Designs from the Greensward to the Great Lawn, to be published by Abrams in 2018. The Greensward is the master plan submitted in 1858 as part of the proposal of landscape architects Frederick Law Olmsted and Calvert Vaux for the Central Park design competition. Executed in India and sepia ink on paper, the Greensward Plan, and the Park itself, are considered masterpieces of 19th-Century landscape design.
After winning the competition, the Greensward was displayed, along with the three runner-up proposals, for public comment. It then was kept at the former convent of Mount St. Vincent, in the northeast corner of the park, which served as park headquarters in the early days of construction. Park offices later moved to the Arsenal building on 5th Avenue, where the Greensward has been on display since at least the 1930s. In the early 1980s, the Parks Department had the Greensward professionally conserved and it was remounted in its original frame. Recently accessioned by the Municipal Archives, the Greensward required updated conservation work and digitization for the book and for a facsimile to be returned to the Arsenal. In late 2018, the Plan will travel to Princeton University for an exhibition.
The oversize and cumbersome formats of many of the historical treasures in the Municipal Archives present special challenges for archivists as they work to preserve and provide access to the collections. The Greensward Plan was too large (it measures 9 feet by 2 ½ feet) for our existing digitization stations. Our best option was to rent equipment and digitize in-house both to save on the cost and to reduce the chance of damage to this irreplaceable artifact.
Since we would be renting the photo equipment for a week, we decided to digitize additional oversize items. A committee of digital technicians, conservators, and archivists chose several other parks-related maps and drawings that were already on-site. The equipment would be available for only three full days, giving us time to complete an estimated 5 to 10 maps. This estimate accounted for numerous possible challenges such as equipment malfunction and dealing with the delicate condition of some materials.
How we did it:
We chose a room that could be dedicated to this project, with a layout that allowed us to move oversize items fairly easily and set up a shooting schedule. The team identified items for digitization, assessed conditions and prepared the materials, established network access, and developed a creative solution for digitizing the oversize and fragile objects.
The space had to be big enough to accommodate the widest measurements of each of our maps. Our 6x25 foot shooting area allowed us to move our four-foot-wide map three feet in either direction, and twelve-foot-long map twelve-feet in either direction. To make up for not having a four-foot width to work with, we had to flip our widest maps 180 degrees to get the last row of images.
Once we identified a space of suitable size to accommodate our over-size items, we carefully HEPA-vacuumed the floors and corners for any debris. We covered the clean floor with plain brown paper, taped the seams, and designated blotters for visitors to wipe their shoes on (although shooting staff was encouraged to take their shoes off while working).
Evaluate analog material
Selecting items for digitization required consideration of each map’s physical characteristics and condition. Sizes ranged from 2x12 feet, to 4x21 feet, and the objects were in various states of preservation. Our conservation team was consulted on condition, handling practices and preparation of the maps for digitization. This included removing the Greensward Plan from its original frame, and humidification and flattening of the very long Sketch Map of the City of New York and Vicinity, which had been rolled in a metal tube for over a century. The largest item, a map of the City of New York from the Department of Docks circa 1872, had been previously archivally adhered to a flexible backing, making it less challenging to digitize than some smaller items that lacked backing.
Assess equipment available and equipment required
We decided to replicate a copy stand set-up, but on a grand scale. Using one of our Phase One IQ180 medium-format digital backs with the addition of a Phase One XF camera body and 80mm lens rental made the most sense. In addition, we rented a Porta Jib traveler on which the camera was mounted. This allowed us to shoot down at a 90-degree angle while maintaining a level camera and kept the legs of the tripod out of the frame.
Since the viewfinder was out of reach during shooting, we tethered the camera to a Mac Pro to focus and quickly QC each image. We installed Capture One Cultural Heritage software to create our LCC profile and rapidly view RAW files. Soon, all that remained was collecting supplies that would be needed once our equipment arrived, color card, paper weights, measuring tape, and masking tape.
Set up equipment
We were able to give the camera a three-foot reach from the base of the tripod. To maintain even lighting and reach for larger objects, we were required to keep one light mounted on a boom. Marking the edges of the frame on the floor with masking tape allowed us to move the object without cutting off any information and keep it straight.
Digitizing in sections
We decided early on to move the objects frame by frame, rather than move the equipment. Although moving the equipment would have allowed us to work in a smaller space, it would create risks such as uneven lighting or the camera moving up or down, etc. All of these factors could have led to issues when reassembling the images later on. We measured the distance from the camera sensor to the floor to calculate PPI, and set the tripod head to face down at 90 degrees. From there, we double-checked the focus before shooting each object.
Photoshop has a very powerful auto-stitch feature, but it requires some manual fine tuning. This stitching script from Digital Transitions is also an incredibly helpful tool. The main concern is working on a computer that can handle very large file sizes, our final flattened TIFF for the Greensward was 1.19 GB.
The Greensward Plan was successfully digitized in a day. After repairing and stabilizing the frame, it has returned to its home. Six other drawings were digitized that week including a beautiful Department of Docks drawing circa 1873, and the astoundingly well-preserved Sketch Map of the City of New York and Vicinity with tiny fairies drawn above the title.