Crowdsourcing Fieldwork: A Neuroarchaeology Project?

How should an exhibit be lit?

How should an exhibit be lit?

This is a devel­op­ment of an idea I had last year after read­ing a post by Christina on a visit to the National Museum in Copenhagen. In short most museums I go to seem to have much darker gal­ler­ies for pre­his­toric mater­ial that clas­sical mater­ial. That has to have a psy­cho­lo­gical effect, but does it also have a physiolo­gical effect? Is the dif­fer­ence in light enough that there’s a dif­fer­ence feel­ing to observing pre­his­toric mater­ial to clas­sical mater­ial because of the room and not the con­tent? You could also ask sim­ilar ques­tions of European and Rest of the World exhib­its. Are African exhib­its in more dimly lit rooms, and if so what does this say about ‘world museums’.

It should be an easy enough ques­tion to answer; simply visit a range of museums in exotic loc­a­tions with a light-meter and then number-crunch to find the answer. That’s not very effi­cient though. It means arran­ging per­mis­sions, trav­el­ling to the museums, and log­ging the data. It could take three or four days in terms of travel to some places to log 50 num­bers. When it comes to num­ber crunch­ing more is bet­ter so is there a way round this? I sup­pose I could hire people to wander round museums for me with light­meters, but that would be expens­ive and my bank is already exper­i­ment­ing with new shades of red to print my bal­ance. It’d be handy if I could just find the data I want lying around the net some­where. Regular read­ers will know I’ve been think­ing about Flickr’s API a lot, and they won’t be sur­prised to hear that’s where I might have found the answer. A lot of people have been tak­ing pho­tos in museums and I think they could help.

It might sound bleed­ing obvi­ous that all of Flickr’s pho­tos were taken with a cam­era, but in the case of digital cam­eras Flickr can also store a lot more data. Attached to a lot of the pho­tos is EXIF data. If you visit a photo like this one, you’ll see there’s a more prop­er­ties link on the right side of the page. That takes you to a page like this one. It tells you the ISO set­ting, aper­ture and shut­ter speed for a photo. ((Usually — HDR pho­tos won’t because the have mul­tiple expos­ures)) If the cam­era is auto­matic then it will pick what it thinks are the best set­tings. The cam­era is set to manual, then the pho­to­grapher is still prob­ably going to choose what it thinks are the best set­tings. Therefore this gives a way to cal­cu­late rel­at­ive changes in light.

For example ISO set­tings come from the days when people used film for pho­tos. ISO 200 would react to light one ‘stop’ faster than ISO 100. ISO 400 was one stop faster than ISO 200 and two than ISO 100. So the ISO set­ting will let us cal­cu­late how many stops down the film speed is. The aper­ture is an odd scale because it relates to the size of the aper­ture of the lens rel­at­ive to the focal length. But it can be cal­cu­lated, f/22 is a stop up from  f/16 and f/11 is another stop down and so on. The same can be said for shut­ter speed You can go from 1/800 to 1/400 to 1/200 and so on.

Therefore, if you fix a datum you can meas­ure how many stops up or down from that datum a photo is from the EXIF data. This is related to the light in the image and the cam­era lens look­ing into a gal­lery or dis­play is a proxy for the human eye. It’s not per­fect, you’d want a lot of pho­tos but one thing Flickr has is a LOT of pho­tos. It also has the API, which makes it very easy to trans­fer the rel­ev­ant meta-data into a data­base for interrogation.

One reason I’m inter­ested in doing this pro­ject is that I have no idea what the res­ult would be. It could be emphatic, ambigu­ous or show that I have a very select­ive memory when it comes to light­ing. It might sound obvi­ous that you’d want to research some­thing you don’t know the answer to, but to gain fund­ing you have to show a like­li­hood of a pos­it­ive out­come — or that the meth­od­o­logy is at least sound. I don’t know if this is the case, so the pro­ject won’t attract fund­ing, but the API makes it cheap. Certainly cheaper than fly­ing on budget air­lines round Europe.

In terms of pub­lic­a­tion it seems like a good fit for Internet Archaeology. Internet Archaeology is mov­ing in steps towards open access. Given the… umm… eccent­ric atti­tude the AHRC takes to digital media, and the cur­rent eco­nomic cli­mate that’s a dif­fi­cult move they’re mak­ing. The fact they are mov­ing to Open Access makes it one of the most attract­ive ven­ues to pub­lish in aca­demic archae­ology. In this instance a data­base which can link back to the source files at Flickr would fit neatly into their hyperlink-friendly model. A bit of ingenu­ity with the SQL quer­ies and data­base fields and it should be pos­sible to make it a use­ful applic­a­tion for fur­ther research.

The biggest prob­lem I see at the moment is whether or not estim­at­ing rel­at­ive light levels from the ISO, aper­ture and shut­ter speed will be enough to dis­tin­guish between genu­ine dif­fer­ences in light­ing. There are other non-trivial ques­tions. If pho­tos are of the exhib­its rather than the gal­ler­ies, then will the arti­fi­cial light neg­ate any meas­ur­able dif­fer­ences? It would cer­tainly lose dark­ness in the peri­pheral vis­ion. How do I gather the data? Can I pull it straight from the EXIF files from any photo on the site, but would this be reas­on­able if the photo itself is set to copy­right? Would set­ting up a Flickr group for the pro­ject and try­ing to herd in volun­teers, or stick­ing to CC licenced pho­tos be better?

I think I could prob­ably set up a small-scale test of this over the autumn and then take it from there, Still, it would be help­ful if someone could spot all the flaws in this plan for me, rather than leav­ing me to stumble into them, so feel free to leave your com­ments below.


When he's not tired, fixing his car or caught in train delays, Alun Salt works part-time for the Annals of Botany weblog. His PhD was in ancient science at the University of Leicester, but he doesn't know Richard III.

1 Response

  1. September 23, 2009

    […] asks a really fas­cin­at­ing ques­tion in Crowdsourcing Fieldwork: A Neuroarchaeology Project? – does light­ing make a dif­fer­ence? I would love to know the answer to […]