"John Bradshaw" <joh### [at] nospamhotmailcom> wrote in message
news:3c72e14a@news.povray.org...
> Also, would like comments on the scanning electron microscope effect. It's
> not quite where I want it to be, but getting there. (see previous post SEM
> texture)

I reviewed that teapot image with an SEM expert and these were our comments
there, many of which would apply to your image...

An SEM has a detector off to one side.  So in effect surfaces which face the
detector will be brighter (higher collection yield) than those which face
away. Your image gives the feeling that the detector is in the center of the
sample, if there's not multiple light sources.

The image rightly shows how surfaces which are normal to the "camera" ie.,
incident beam are brighter. Again, the secondary electron detection yield is
higher as well on these surfaces.   This is a good *pigment*, FWIW.

It looks, however, as if it were stainless steel, with very little beam
penetration into the sample.  Contrast this with "record 22 of 700; Title:
'Blood cell' " in the image gallery at.
http://www.uq.edu.au/nanoworld/images_1.html

For an organic, low-atomic-number sample, I'd expect there to be some
translucency, almost a 'media' effect, as in that blood cell image

The "etched steel" effect in your texture normal is a bit troublesome.  Here
the concern is not so much with SEM physics but with the intuitive feel of
cells: things should be more round, even like "Lung surface: image 39 of
700" at that gallery.


_________
Greg M. Johnson
10-yr SEM user

Post a reply to this message