Jaak Rand, Mari Siiner, Jaanus Heinla, Kairi Kruus, Martin Sermat (Estonian Open Air Museum, Conservation Centre Kanut)

Digitisation of a Large- Scale (3800 x 4212 mm) Hand-Painted Topographic Map of Palmse Manor Estate, Dated 1859-1864

This paper is about the digitisation of a large scale museum object, and describes the making  of user copies for the museum.

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Today, the term  “digitization” covers a large range of activities from choice of object to be digitised through to possible end use of the digital material. For instance, the museums  have taken steps to make their collections accessible not only on-line at the click of a button. It means, in some cases, aside the digital files of the item, the printed repro derived from digital files is a good choice for museum visitors.

For CDC Kanut, the request was somewhat similar to the situation described above: replacing an original historical item with the repro which would have the similar scale for the user purposes.

Namely, Palmse Manor representatives wanted a large scale map to be renewed and placed back to its previous place – on the wall in the manor house exibition room.

Maris Allik, the leading conservator on that task, said: „The conservation task is a challenge firstly because of the large dimensions of the map and the water sensitive media (inks, watercolour paints, and the paper itself), but it is challenging also due to the fact that the unique document has a community value, and has to be available for examination by local people. Last but not least, there is no wall large enough in the Manor House for proper exhibiting of the original, and alternative methods have to be considered, starting with the digitization of the map. That is not an easy task for large scale documents.”

This is the moment where the idea to go for the repro first sparks.

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1. Map size

First off, the object is a large scale (3800 x 4212 mm) hand painted topographic map of Palmse Manor estate, dated 1859-1864.

The size, format of this insular map  and the scale in which it was drawn is very rare.

The scale is indicated  on the map – 500 Faden (fathom) to 10 Zoll (inch). The scale is given as a bar, divided into five sections for each section with 100 fathom to 2 inch. That calculated  in centimeters (by Christof Nichterlein) is 1 : 4200 … 42 meters on land equals 1 centimeters on map.

2. Physical state and condition of the map

The damaged map was exhibited openly over 15 years by hanging on the wall and never left the Manor until autumn 2018, when it was brought to CDC Kanut for conservation and preparation for digitizing. The map was properly prepared for digitizing within 5 months.

3. Setting for digitization

*Black box type studio
*Scanner: RENCAY Archive Scanback + RENVIEW Software
*Lightning: LED Light Typ4, 5.000 Kelvin, 150 Watt, daylight
*The imaging task at hand measures 16 times the size of DIN AØ format. Therefore, the prepared map was scanned by pieces equal to meet the necessary resolution.
*The piece: H 133cm x W 210 cm, all together 8 frames/images.
*Resolution: 13000 x 8000 pixels.
*File size per piece (48bit TIFF): 450-610 MB

4. Background of the map digitisation.

The first step of digitising The Estate Map of Palmse Manor was made in 2015

by Christof Nichterlein from Karlsruhe University of Applied Sciences, Faculty of Information Management and Media.

The  aim of his Bachelor Thesis[i]  was to bring this heavily damaged map from the wall into a digital version, and to compare it with the Estonian Basic Maps, current landscape situation in 2015.

Another aim for his thesis was to find a method which would adequately describe any kind of estate maps in general and they would be presented in a small web application. This work united methods of photography, of georeferencing, of digitising and of analysing in GIS (geographic information system). Also, the creation of an open source web map viewer was under consideration. Before his work the map was not archived or catalogued.

Before 2015, the map was not entirely rolled out for exibition. The height of the exposition room was less than 3 meters, and about 60 cm of the map lied on the floor rolled into bulge. Christof was able to lay the rolled bulge on the floor for visual access. No other manoeuvres for the map were possible, hence, he took the pictures of the map as it was placed in the Manor House exhibition room. You can imagine the technical issues he faced when placing 2D item in 3D manner – positioning the camera, sharpening the details on surface, etc. Not to mention – he was not allowed to use controlled light system, and he could only use the natural daylight shed from the left side of the room windows, in addition to stationary room lights. 

However, 54 photos of the map were taken. Combining and merging them side by side he created the first intact digital version of the map. The resolution of this map came out on resolution of 72 dpi. Camera used for that particular task was Canon EOS 5D Mark II with 50mm prime lens.

3.  Step by step:

Taking into account the previous research on the map and the on-site evaluations and expertise in 2018, prior to conservation, CDC Kanut had sufficient tips and overview of the oncoming tasks as well as possible issues. Thus, the chronology of the conservation and digitization process went as follows:

* The map was brought into Kanut facility for repairs and preparation in January in 2019. Preparation goal: to send it back to Palms Manor as a repaired showpiece item. By requirement, the map was to have improved physical state and carry the historical data and chartographical value as an exhibit. In other words, the map would have to represent the same detailed value of the Palmse lands as it was new…

* It was obvious that an item such as Palmse Estate Map – made out of paper, and with that size while kept in the abovementioned circumstances over a decade – would not withstand the future goals and functions forced on it merely by the aid of basic conservation process.

* To avoid further deterioration of the map, the best solution was to undergo the repro making process, and prepare the original for the safe keeping. The claim for the repro was that it needed to maintain the native resolution and maximum possible dimensions to fit on the manor wall. In this respect, the experience and notes by Christof Nichterlein came in very handy.

* Next, we needed a controlled light studio, equipment for saving the images, and eventually to send it to printshop.  At that point, after the basic conservation jobs were finished, the map was taken into studio in CDC Kanut facility for imaging.

* In regular digitizing process, the full image (general view) of the large item would not have to be in high detail quality because the details about the items’ general view are added to the archive folders. But in order to make a repro, the flow of digitizing process turns from archive folder creation to reprint file image processing. And for that purpose, the digitizing process for archive turns into image rendering process for print shop.

* Both the print job and the image processing for the print version of the map were conducted by Artproof – one of the most professional partners in our repro industry… Followed by more test prints.

* For the human eye to have the virtually similar image resolution on-print, the printing resolution would have to be 250-300 dpi. We downscaled the map actual size from 1 to 0,7. Resolution of the print copy came as high as 210 dpi. The image sent to printer was in two tiles, each 24k x 14k pixels. To give you the perspective of the entire image of that size on print, the same visual detail for human eye would be seen on 76 monitors (4K) placed side by side as a monoscreen.

*The repro was printed on acrylic latex coated canvas. [fredrix 901sj]

* To sum up: given the circumstances and previously set goals brought us a repro, a digital user copy by print that can be now seen for visitors in the Palmse Manor.

* High quality  preservation copies were made  with the aim to preserve the conserved original. The original map is rolled all the way back and packed for safekeeping.

Conclusion:

The map was digitized twice between the years 2015-2019 for different purposes. The aim of Christof Nichterlein’s approach was to digitize the damaged map in the place of exhibition area in Palmse Manor for analysing it in GIS and also to create an open source web map viewer.

The second step of digitizing the map was more complex considering the future purposes for map usage. It was followed by both preservation and access  requirements for the map. The conserved map was digitized in studio, arranged for this on special workplace and lighting environment. Printed derivate was framed and exhibited in the museum. Conserved original map was rolled, properly packaged and preserved in manor depository.

Finally, the challenge was met successfully.


[i] Bachelor Thesis written by Christof Nichterlein.    The Estate Map of Palmse Manor. A Comparison of Past and Today and the Way to an Open Source WMS, 2015/2016   Karlsruhe University of Applied Sciences Faculty of Information Management and Media