After a half day visiting the library at Sheffield Hallam University (post to follow soon), I attended a lunchtime talk entitled ‘Objects in 3D: Creating a virtual metalwork collection’, given by Lucy Cooper, Curator of Metalwork at Museums Sheffield. The talk was at the Millenium Gallery, here in Sheffield, which is just across the road from Hallam.
The Metalwork collection consists of about 13,000 items, 9000 of which are cutlery and flatware, and the remainder is holloware, such as teapots. A large number of the pieces are in store, and the metalwork team try to provide access to them when they can. However, this is often difficult. For example, items taken out for special events must be able to withstand being handled.
The metalwork collection is divided into three types. Firstly, the old Sheffield plate, which is silverlike, but with a base layer of copper, and was invented in Sheffield. There is also the stainless steel collection, which is largely focused on the last 100 years, and is quite a modern collection. It includes items designed by David Mellor, who is a bit of a legend in my book (he designed traffic lights. TRAFFIC LIGHTS). thirdly, there are several hundred items from around the world, such as cutlery sets from other countries.
The aim of the digitisation project was to get some of these items into the public eye. About 1000 objects will eventually be in the online collection. Sheffield Hallam University approached Museums Sheffield with the idea to create 3D digitised images, and with their help they procured funding from JISC for 5 months work.
Choosing the Objects
This was the part that Lucy found most fun!
The team tried to select objects that had little exposure in the past, but were stars of the Sheffield scene. The also chose objects that they would be able to contextualise with written information on the website.
Scanning an object takes around 15-20 minutes, depending on the level of detail. This means they worked through about 20-30 objects per day, over a period of 2 or 3 weeks.
The scanner was attached to a fully moveable arm, meaning they could move the beam around the object while it remains perfectly still. A full scan was taken, including the underneath of items, so a lot of museum foam was used to create supports for those objects that couldn’t support themselves, or were perhaps delicate.
One of the unforseen issues with scanning was that the beam would reflect from pieces. As such, they decided to select duller objects, such as those made from other metals to silver, or items which needed cleaning.
The images are minutely accurate – the tiny bumps that appear on the scan image, are the tiny bumps on the real thing. A lot of museums stop just before this point, but Lucy wanted, if possible, a replacement for seeing the object in real life.
These were taken so they could be put together with the scanned image, to create a complete 3D visualisation. Photos needed to be taken from multiple angles, and needed to map exactly onto the scanned images. according to Lucy, this process, interestingly, probably took as long as scanning the items.
SOme of the items had too many gaps in them, and the scan beam got confused. As a result, it is difficult to unpick the layers and correct the data. Lucy felt this was a real shame, as there are some beautiful pierced Sheffield plate fruit bowls that she would have loved to have included, but the image just would not have worked.
The scan images themselves were too large to be hosted on the web, so had to be compressed. This sadly losses some detail, but they have kept some archival large files at the museum.
There was also a process of quality checking before putting them on the website, and about 20% of the models needed correcting.
The objects are arranged into thematic categories, such as food, drink, tools, etc. The images appear instantly, so do not need to be downloaded, and can be manipulated – you can zoom or turn the object. SOme research information has been added to the object, and there are also learning resources available for download for schools.
Lucy wants to integrate the objects into the main collection search. She would also like to be able to repeat the process for more delicate, fragile, or damaged objects. In the future, improved technology would also facilitate enhanced details, such as hallmarks.
I really enjoyed the presentation, especially when Lucy demonstrated the teapot-cum-photoframe. It was interesting to attend a talk aimed at the general public, but on a topic that is also very relevant to LIS.