Monday 25 February 2013

Amara West

I have just returned from 3 weeks in Sudan with the British Museum, photographing the Ancient Egyptian town of Amara West on the banks of the Nile. I have 180GB of photographs of the town which should allow me to recreate the entire town as a 3D pointcloud. Now for several weeks of processing...




I also have over 5000 aerial images from some very successful kite launches. The wind from the desert is very steady and constant- though at times too strong. This should allow me to build up an elevation map of the area and learn more about the ancient paleochannel of the Nile that once made the site an island. It could also help to spot further burial sites on what was the ancient mainland.




There are several posts on the British Museum blog (including one by me) about my work at Amara West




there are more photos in the other posts on the blog- you can read the whole thing here:




Friday 18 January 2013

Photographing the first Stone Circle

After a lot of reading and soul searching, I have decided that the Archaeological subject of my PhD will be Stone Circles (and a few related monuments)

Unfortunately there are no stone circles anywhere near London, so I took advantage of a Christmas spent with my family in Scotland to capture a circle just a few miles down the road from the place where I grew up. In fact it is one of two rather impressive circles, but it only stopped raining long enough to capture the smaller one, The Loupin Stanes. This translates as the 'Leaping Stones'

The Loupin Stanes looking very bleak on our first visit. It was too wet to take many pictures so we returned a couple of days later.


This time we had about an hour free of rain. Everyone else took measurements  for me to scale the pointcloud while I shot the photos (2000!)


The other stone circle, the Girdle Stanes. This picture gives an idea of how wet it was on our first visit.


Pointcloud and Meshes to follow.....

Sunday 6 January 2013

Infra-red Photography

Last Week I attended Digidoc conference in Edinburgh (http://www.digitaldocumentation.co.uk/) and met a fellow PhD student Kieran Baxter who is looking the use of at Kite Photography to record archaeological sites. His website is here: http://www.topofly.com/ He mentioned that several archaeologists he knows of have experimented with using infra-red cameras when taking kite photographs. Having recently attended a lecture by Stuart Laidlaw at UCL http://www.ucl.ac.uk/archaeology/calendar/articles/20121015 that described the conversion of digital cameras to take infra-red images I decided to try it out on an old camera. I have an Olympus sp-350, which turns out to be a very suitable camera for conversion. There are instructions here for a variety of digital cameras: http://www.scaredycatfilms.com/digicam_mods/index.html All digital camera sensors can record infra-red light, but they are fitted with a filter to block it out- so you have to open up the camera and remove the filter. This is my first image with the filter removed. It is out of focus because the filter is used to correctly focus the image. I was very excited to see that the ivy shows up as red. The second image shows the same scene on my NEX-7

Infra-red filter removed Visible light only

In order to block out normal visible light you have to replace the filter. As yet I don't have a proper visible light filter, but the scardycatfilms website suggested using a piece of exposed negative. I combined this with two pieces of clear plastic to make up the same thickness as the original filter (to re-establish the correct focus). The results look like this:
















and a little bit of playing with Photoshop filters (the original was a raw image) pulls out the vegetation from the rest of the scene:


  In order to try out the filter properly I cycled out into the countryside and took some very nice, slightly spooky images as shown below. Infra-red light makes a useful addition to the archaeologists toolbox when reading satellite images, so I think it would be useful to try out some infra-red kite photos and see if I can integrate them with a sfm pointcloud.











 some links: http://www.armadale.org.uk/phototech05.htm http://www.academia.edu/1155568/Near-InfraRed_Aerial_Crop_Mark_Archaeology_From_Its_Historical_Use_to_Current_Digital_Implementations Geert Verhoeven