The Javelin Warrior: Multispectral Bronze Age Rock Carving

[nfoto]

I returned today from a trip to my friendly neighbouring country, Sweden, where I have spent a few days shooting Bronze Age rock carvings. These beautiful expressions of prehistoric artwork were actually engraved into the rock face using a small rounded stone as the sole tool. The artwork followed Man's migration up along the coastline of the Scandinavian pensinsula as the Ice sheet retreated many thousand of years ago. When they were made, the sloping rock faces were situated along the shoreline, but centuries of land uplift have put them much further inland so you find them today far from the coast proper. The rock faces deemed ideal for use as a "canvas" seems to be gently sloping, facing south or west, and kept free of vegetation by trickling seepage water. A selected number of sites with rock carvings are placed on the World Heritage list.

The carvings can be difficult to observe unless they are set off with red paint (and even then, the paint wears quickly, and the figures are mainly painted in the tourist season). Neither are you allowed to walk the rock faces on which they are found due to the potential damage inflicted. So shooting these ancient creations of man is not always easy. I decided to try out the Coastal 60 mm APO lens and multispectral techniques to see if I could get better pictures.

At a total height of 2.35 m, the mighty "Javelin Warrior" of Litseby in Bohuslän, Sweden, is probably the World's largest rock carving. When I arrived at the site the figure had just emerged from its snow cover and blended almost entirely into the framework of rock surrounding it.

The Javelin Warrior is presumed to date from 1200 BC and is engraved over older carvings (several drawings of longships). The depiction might be that of the ancient Nordic god, Odin (Wotan or Woden). Noboy knows for sure today since there are no written records of course.

Here is how the rock face with the Javelin Warrior figure looked, after a very healthy boost of contrast to bring the carving forward:



And this is the multispectral capture using UV, visible/green, and IR. Note that many additional carvings appear in the MS image. No doubt about his gender 




Due to the legally imposed vantage point for photography, the figure is significantly forershortened. But one appreciates the artistic expression notwithstanding this minor annoyance.

[DaveOHUSA]

Very nice technique which seems to bring this image to life, showing the depth... very interesting on the history too... Thanks for sharing this image and MS technique.  Beautiful application well executed.  I appreciate this very much.

[Carolyn]

Wonderful rock carving. Must be awesome in person to see a carving of that size. Most of the rock art in Utah are inches to a foot or two. The UV really makes it all show up. Thanks tons for sharing this.

[olivier]

Very intreeguing. I would be interested in knowing how a carved stone renders such different "colors", meaning reflection/absorption of quite different wavelenghts.

[brianc1959]

Bjørn:
A very interesting result.  Do you think the IR reflectance is due to residual paint, or due to the underlying carving?

Brian

[Akira]

Bjørn,

Thanks for sharing this intriguing image.  There is one thing I wonder except for the laughable addition revealed by the MS image technique.  Are the surrounding small carvings rendered in red all original ones?

[nfoto]

A common answer to your questions is that the rock surface obviously has been altered by the artist when (presumably) he knocked out the shape of the figure(s) using his small round stone. Thus IR reflectance has increased even for carvings never painted. Some of the figures apparent in the MS image were absolutely invisible to the naked eye.

[bjornthun]

Bjørn: Very interesting picture. You get a lot of details out of the motive. Do museums/archaeologists use the technique you used or similar ones for scientific mapping of carvings?

There are stone carvings around where I live. Wonder what might become visible, if I try to shoot them? 

[Marco]

The carvind really comes alive when showing with the coastal 60mm apo lens, i immediatly thougth of the paintings/carvings i saw on my trip in northern australia who knows what shows up when using this technique!
Thx for sharing Bjørn.

Marco.

[James Fitzgerald]

Bjørn,

Thanks for showing this image. I find it very very interesting.

Rock Art in the southwest US is an interest of mine. Your photo has inspired me to convert my D200 when funds allow.

In the meantime I have been considering trying a plug in for image J called DStretch written by Dr. Jon Harman. Are you familiar with this? if so, do you have any thoughts on this software?

Thanks

[Shane]

Great image and interesting application.

[kds315]

Examining that interesting result yields (IMHO) mainly the following:
- the visual (mapped to green channel) information is close to zero
- the majority of the information is contained in the IR (mapped to red) channel
- UV (mapped to blue channel) serves as a "negative print" to enhance the IR info (except the second blue spear above)

It is interesting to see that a bit of that red = NIR info is already contained in the visual image if looked closely

nice application!

[nfoto]

There is no "second blue spear", this is a small fissure in the bedrock itself, Klaus.

The spectral response of the carvings varied a lot between the various sites I visited. Not all had a strong IR response, in fact some even came forward in UV. So I could show figures that appeared yellow or blueish green instead, but were acquired using the identical technique and filtration as with the Javelin Warrior.

[papa-g]

Fascinating..

We have a large number of Bushmen rock paintings all over the Drakensberg - would this technique also work for paint (albeit very faded) ?

Geoff

[nfoto]

Most likely.

[nfoto]

Here is an example from another site, in which the carvings partly were covered by lichens. The identical filtration and multispectral (MS) technique used here as well. One can appreciate that although MS does indeed work, the outcome [in terms of the actual colour balance] is not always predictable. The figure here is on a much smaller scale, about 30 cm or so total height (see lichen thalli as a size reference).

[kds315]

Is the outcome depending on the shooting vs. light (UV, VIS, IR) angle??
From my experience the reflectance of UV, VIS and IR are (or can be)
very different more or less, independently of the subject/target.

[nfoto]

Since I had heavily overcast ambient conditions all the time, I very much doubt that angle of reflectance came into play.

[diglloyd]

Fascinating..

We have a large number of Bushmen rock paintings all over the Drakensberg - would this technique also work for paint (albeit very faded) ?

I don't know about  your specific subject, but here in the US, I have photographed (in infrared) painted-over graffiti that looks "clean" to the eye, but reveals the graffiti underneath.  So the technique Bjørn has shown is of general use to many subjects, give it a try.

[annedi]

I'm traveling, but just dropped in to say "WOW" to your MS rock carvings.