Cultural Heritage Digitisation Service

This year’s conference was hosted by The Imperial War Museum London. Diane Lees Director-General of the Imperial War Museums opened this year’s conference with the idea that “Photography delivers the curatorial message”. The presentations that followed certainly backed that statement up and demonstrated the complexity of support that photography brings to the curatorial message. Of particular note during a varied day of talks an emphasis on photogrammetry emerged as opposed to 3D scanning. The presentations that left an impression on me are discussed below but abstracts of all the conference talks can be found here:

http://www.ahfap.org.uk/conferences/2016-conference/2016-abstracts/

The Drexel Digital Museum: Interpreting the digital historic fashion object.

This was a very engaging presentation by Daniel Caufield-Sriklad. He highlighted that there needs to be a different approach to digital interpretation as opposed to physical museum interpretation. Within his presentation he demonstrated how the Drexel Digital museum web site pulled in many different sources of information relating to the one physical object in the collection. Each object entry online could contain still photographs of the object and dedicated detailed shots. The entry would also contain moving image sequences and sound recordings relating to that object. In addition the object entry would also contain Giga Pan Process capturing 720 images per object and stitched those together to give a detailed 360 degree view of the object. These images “can be displayed at 1:1 scale, rotated 360 degrees, and zoomed into details far beyond what can be perceived by the unaided human eye”. 3D Motion capture was also used to create a 3D model to demonstrate the garment during movement using digital draping technology. HTML 5 was used to deliver their site. The overall approach provides multiple layers of interpretation in one central space.

http://digimuse2.westphal.drexel.edu/publicdrexel/index.php

http://gigapan.com/

http://www.danielc-s.com/portfolio/drexel-digital-museum/

The Strines Journal: Practice-led research into Historic Photographic Processes

Tony Richards from John Rylands Library Manchester gave an illuminating talk on his journey of trying to reproduce historic photographic processing. This included a lot of research into early wet processing formulas and their execution in studio practice. It revealed that published practice was misleading at times and it took a lot of cross referencing of published early formulas to finally achieve any kind of results similar to the early photographic collections that we hold in our museums. This work has brought the early photographic process to life again through in depth practice and research. Definitely an expert view in relation to our early photographic collections.

Digitising, Geo referencing and Transcribing 1100 Tithe maps

Scott Waby from The National Library of Wales delivered an engaging and well-paced talk on the progress of the project. It is an ambitious project to layer the Welsh national historical collection of maps on top of current map data for Wales. Scott and his team built a large curved magnetic wall to facilitate pin sharp capture of large maps in the collection. They had noticed that focus was falling off towards the edges of the map capture and so devised the curved wall to maintain the same focal length across the entire map whilst keeping the camera in a fixed position.

Day Two Workshops

 Tate Britians move to Digital X-Ray
An opportunity to view Tate’s new digital x-ray system launched in January this year, replacing old x-ray set with a more powerful one and specially designed art table.

Fascinating insight into the digital x-ray world. At a cost of £93k Tate Britain have established a digital x-ray work flow. The results of which have uncovered the working process of artist like Picasso, Rene Magritte and Reynolds to name a few. This appeared labour intensive with all six staff having to vacate the studio each time an x-ray is triggered. The capture area is around A3 size so the larger works require multiple exposures which are then stitched together and for the medium sized Reynolds painting that was demonstrated final image was around 1.45 Gb. This in itself adds another cost in terms of processing images. The set up included a tripod to mount the X-Ray generator for use in the field. This also included guidelines and markers to calibrate safe distances before triggering the x-ray.

All round a challenge to implement requiring government inspectors to assure no health risk and a sizeable space away from people. Obviously the final images are a huge boon to conservators and people marketing and studying these historic processes.

Metamorfoze Preservation Imaging Guidelines and its daily use 

Hans van Dormolen & Tony Harris

This was a practical real world walk through of studio implementation of the Metamorphose   guidelines approved by unanimous vote at 2D + 3D Practices and Prophecies conference 2014 Rijksmuseum Amsterdam. Metamorphose guidelines are now law in the Netherlands if you are photographing national collections. The guidelines were written over a seven year period of research by Hans van Dormolen a researcher at UK Government Art Collection.

The walk through consisted of a standard copy stand set up with lights and camera in a static position photographing a large version x-rite colour chart. The main opening point driven home by Hans was “Gain Modulation”. Put simply the lights and camera and distance from object all have to remain static in order to maintain a consistent gain modulation. Readings are taken from the digital image of the chart using capture one sampling tool focussing on the reading shown in the green band. These readings are then checked against the Metamorphose guidelines and adjustments are made to the lights until the required readings are achieved. This took 6-7 adjustments to the lights. There is a small tolerance allowed within the guidelines. Once the initial target square patch E5 on the x-rite reads at 242 the setting is achieved and reading continues on J6, F5, I6, K6, G5 etc. following the guidelines.

Hans noted that each x-rite chart has a batch number and advised that more recent charts would aid accuracy. Also clean your chart from dust. After numerous studio tests Hans also noted that a black background was preferable for placing your chart on for optimum colour accuracy.

The walk through diverged at this point into discussion around uniform illumination and how one could check this by photographing a white sheet of paper and using Photoshop’s histogram palette, using the illumination drop down menu and referring those readings to the Metamorphose guidelines. Uniform illumination can also be checked using the threshold tool again in Photoshop and noting the values at the point where black begins to enter the image and the point where white almost leaves the image.

The workshop never completed the task of calibrating for colour accuracy in the two and a half hour slot allocated with it has to be said the experts driving. It’s a complicated task to image using the guidelines and would only be useful in a real world setting where lighting and object distance were static so that gain modulation was static. However this could be achieved on projects that have same size objects like our recent glass plate negative project.

The Imperial War Museum was an astonishing museum in many ways, it had very clever use of moving images that merged with physical collections in an immersive way. However I was struck by just how much energy and physical effort and ingenuity human beings put into killing each other. Tremendously sad.

Malcolm Brown Deputy Photographer Library & University Collections Digital Imaging Unit