Corgarff Castle and Elgin Cathedral

It’s been almost 2 weeks since my fieldwork trip to the Highlands – a 4-day survey whirlwind through several locations in the North of Scotland, including Inverness, Elgin, Fortrose and Corgarff. Most of my time was spent laser scanning Corgarff Castle – together with HES colleagues from the Fort George office and Li Sou from Historic England. Corgarff is a very special site: a striking white garrison tower surrounded by star-shaped walls, located at the edge of Cairngorms National Park. The location is very remote, but the views were stunning.

One of the highlights of the trip was certainly my return to Elgin Cathedral. Elgin was my first field project with the Digital Documentation team and provided the material for my very first post on this blog (see Elgin Cathedral QTVR). The objective was to photograph the interiors of the two towers of the Cathedral in order to produce a new set of QTVR panoramas – documenting the spaces after the installation of the new interpretation suite. We used the same set-up as before (Nikon D810 mounted on survey tripod using nodal ninja) with a few improvements (HDR photography using 5 brackets instead of 3, plus remote shutter release to eliminate movement). The system worked really well and we managed to finish the job in a few hours with great results. The only (slight) downside of this process: 5 brackets for every angle (3 rotations plus ceiling shots) resulted in approx. 150 images for each location (in RAW and JPG) = a lot of storage space. However, the quality of the final panoramas definitely justifies the file sizes!

I have already processed the raw photos in Photomatix to create the HDR images, which I’m now stitching together in PTGui to produce the panoramas. I’ve been using only RAW photographs for processing and exporting uncompressed TIFs, which doesn’t seem to add much to processing time, but really makes a difference to the quality of the final product.

My visit to Elgin was a great chance to finally see the stone collection properly displayed in the brand new exhibition, after a year of conservation work – which took place literally next door to our office in Edinburgh, in the HES Conservation Centre. The dark purple display stands were a perfect choice for showcasing the stones. The effigy of the bishop is one of the highlights of the collection – the light projection system used to display the colour scheme onto the stone is brilliant.


Colour scheme projected onto the stone effigy.

Once the QTVRs are completed, my next project will be to process all the laser scan data from Corgarff Castle and Fortrose Cathedral. I’ve already imported all the data into Cyclone using the Auto-Align function, with moderate success (it gets confused by repeating geometry such as staircases with sometimes “interesting” results). However, auto-align can be a great tool for quickly checking results at the end of each day on the field – when there is still a chance to go back and fill in any gaps.