CONTENTS OF ISSUE OF "Rock Art Research" linkWorld

BottonVolume 13, Number 2, November 1996

Editorial
A nano approach to the study of rock art: 'The Walkunders', Chillagoe, north
Queensland, Australia
Alan Watchman and Elizabeth Hatte (Australia)
Pigment Analyses from Panther Cave, Texas Marian Hyman, Solveig
A. Turpin and Michael E. Zolensky (U.S.A.)
Material culture in Kimberley rock art, Australia David M. Welch (Australia)
Palaeoindian bedrock petroglyphs at Epullán Grande Cave, northern Patagonia,
Argentina
Eduardo A. Crivelli Montero and Mabel M. Fernández (Argentina)
With Comment by R. G. Bednarik

RAR Debates
Ethical and conservation issues in removing lichens from petroglyphs, by
Alice M. Tratebas and Fred Chapman (U.S.A.)
Response to Alice M. Tratebas and Fred Chapman, by Beverly Childers (U.S.A.)

Brief Reports
Cave Paintings in Yunnan, China, by Peng Fei (Japan)
More on massive intervention: the Aspeberget structure, by Paul G. Bahn
(United Kingdom) and Anne-Sophie Hygen (Norway)

Reviews & Abstracts
With contribution by R. G. Bednarik Recent books of interest Recent
papers of interest

Orientation
AURA Inter-Congress Symposium Melbourne symposium field trips
Archaeometry conference Other forthcoming events Input sought for
heritage guidelines Obituary: Professor Herbert F. Nowak Clarification
New AURA members

IFRAO Report No. 17
Let's save Toro Muerto (Peru) Institutum Canarium New IFRAO
member: Eastern States Rock Art Research Association The Meeting in
Machias, Maine Rationale for SIARB Symposium 5: Administration and
conservation of rock art SIARB International Rock Art Congress

At last! The definitive volume on rock art management and preservation

The following volume has been released by AURA in September 1996. It is by
far the most comprehensive book ever published on rock art management and
preservation, featuring the contributions of two of the symposia of the
Second AURA Congress, held in Cairns. This volume, which includes several
contributions by Aboriginal scholars, is absolutely essential reading for
anyone involved in the physical preservation or conservation of rock art,
or in the ethics and techniques of site management, and in the
presentation of public rock art sites. Please order your copy now from
AURA, P.O. Box 216, Caulfield South, Vic. 3162, Australia.

Number 9, 1996: Management of rock imagery, edited by G. K. Ward and L. A.
Ward, bound with Preservation of rock art, edited by A. Thorn and J.
Brunet. Proceedings of Symposia G and H of the Second AURA Congress, with
contributions by 56 authors. 240 pages, 110 plates, 47 line drawings, 16
maps, 20 tables, extensive bibliographies, paperback, RRP $A48.00, 50%
discount for members of IFRAO-affiliated rock art associations. ISBN 0
9586802 0 5.
Special offer to members of IFRAO-affiliated organisations: including
postage and packing, US$30.60 to any country.

Digital colour re-constitution of rock art records
By Robert G. Bednarik, Convener, IFRAO

A major problem in rock art research is that both the rock art and the
photographic record of it have a limited life span. Indeed, the life
expectancy of the latter is considerably shorter than that of the former.
No possible conservation measures can realistically be expected to secure
the perpetual survival of either rock art or its photographs. Calibrated
electronic preservation of rock art imagery is an alternative that has not
been achieved until recently. The idea, essentially, is to store
colour-corrected rock art records digitally, in which form they will
eventually survive indefinitely.
The International Federation of Rock Art Organizations (IFRAO) in
collaboration with the National Museum of Man in India has recently
conducted the first digital colour re-constitution of rock art imagery
(or, indeed, any other imagery). It is now possible, with commercially
available equipment, to recreate the true colour of rock art and rock
patination at the moment a photograph was taken of it (Bednarik and
Seshadri 1995). This compensates for the distortions inherent in all
photography, as well as the fading of photographic dyes due to prolonged
storage. Consequently an image can be rejuvenated at any time, and
repeatedly, until future technology will permit the fully permanent
storage of vast numbers of images. In other words, the fading rock art as
well as the fading photographic record of it can now be preserved
electronically.
The applications of this new technique are very diverse (colour fidelity,
printing, conservation, monitoring, dating, cross-referencing, colour
enhancement, archival storage etc.), and other disciplines are already
using our calibration standard now. Among the people who have decided to
do so are museologists, palaeontologists, archaeologists, soil scientists
and conservators. This calibration reference device system is designed
around the IFRAO Standard Scale.
The IFRAO Standard Scale is being distributed throughout the world by
IFRAO (Bednarik 1994). For best results in photographs, videos or films of
rock art (or indeed any object for purposes requiring very high colour
fidelity) the following recommendations are useful:

1. Recording medium: The colour calibration input should preferably be as
slides (transparencies) or colour negatives.
2. Lighting: Natural lighting is clearly superior to artificial light,
which means that increased exposure times are preferable to the use of
flash or other artificial lighting. Where necessary and possible, use a
sunlight reflector. Avoid direct lighting in dark locations, and when
using artificial lighting, use white light, not yellow halogen light.
3. Direction: Where artificial light is necessary, and especially for
three-dimensional subjects (petro-glyphs, cupules), the light source
should be from the upper left, and the Scale should also be on the left
upper corner of the frame.
4. Area: Full 100 per cent calibration, which would result in a colour
re-constitution adequate for rigorous technical and scientific purposes,
requires that at least 5-10 per cent of the photograph's area should be
occupied by the Scale. With standard lenses this might correspond to a
distance of about 60 cm to 1 m. There is a gradual but initially
negligible loss in reliability as the image area occupied by the Scale
decreases with distance.
5. Distance: One Scale suffices for distances of up to 1.5 m. If uneven
lighting is unavoidable, place the Scale in the better lit section. For
distances between 1.5 and 3 m, two scales must be used for optimal
results: place one of them anywhere suitable, but the second one always
vertically and in the upper left corner of the frame. Beyond a distance of
3 m, the Scale is too small to permit a calibration level approaching 100
percent, because at that distance the colour chips become too small to
obtain precise digital readings from (i.e. using lenses of standard focal
length).
6. Alignment: Care must be taken to position the Scale so that it is
parallel to the predominant plane of the rock art motif, and about the
same distance from the camera lens.
7. Reflection: The Scale has been printed on matt stock, but this does not
eliminate reflection entirely. If a camera-mounted flash is used, the
scale must not be at right angle to the camera's focal axis, and if the
subject is side-lit, the Scale should be perpendicular to the focal axis.

IFRAO, P.O. Box 216, Caulfield South, Vic. 3162

Acknowledgments: The IFRAO Standard Scale and Colour Calibration Projects
have been supported by the Australian Institute of Aboriginal and Torres
Strait Islander Studies, by the Australia-India Council, and by the Indira
Gandhi Rashtriya Manav Sangrahalaya.

References
Bednarik, R. G. 1991. The IFRAO Standard Scale. Rock Art Research 8:
78-79.
Bednarik, R. G. and K. Seshadri 1995. Digital colour re-constitution in
rock art photography.

Rock Art Research 12: 42-51.78
Rock Art Research 1996 - Volume 13, Number 2.


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