[Nhcoll-l] Dusting/powdering skeletal elements prior to photographing

[David Katz]

Rachel,

That is what I expected. I'm working on developing a developing a
photogrammetry protocol for making digital models of skeletal elements.
Photogrammetry does a good job capturing bone shape when the bones have
texture or topography, or preferably both. However, some bones,
particularly cylindrically shaped bones that have been treated so that they
are smooth and shiny, really offer photogrammetry software no noticeable
topography from which to find overlapping points between a set of
photographs.

One option was to try coating the bones. It seemed to me this wouldn't be
workable for the vast majority of collections. Francisco suggested a
polarizer, and I will look into this. I hadn't heard of it before, but I've
now found some reports that polarizers and photogrammetry software work
fine together. The final possibility that shiny long bones shouldn't be
modeled using photogrammetry software.

... We'll see.


On Tue, Aug 19, 2014 at 12:50 PM, David Katz <dckatz at ucdavis.edu> wrote:

> Hello,
>
> I've been told that in order to photograph elements that tend to reflect
> light strongly (teeth, highly polished bones), people sometimes coat them
> with a reflection-reducing powder. I was even told that baby-powder is
> often used.
>
> Realistically, what do natural history curators permit? Specifically, are
> there types of powder coating that are particularly acceptable and
> non-destructive? Are standards different for recent vs. ancient skeletal
> materials?
>
> Thanks for you input.
>
> David
>
> --
> David Katz
> Doctoral Candidate
> Department of Anthropology--Evolutionary Wing
> University of California, Davis
> Young Hall 204
>



-- 
David Katz
Doctoral Candidate
Department of Anthropology--Evolutionary Wing
University of California, Davis
Young Hall 204
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