Gallery Thursday, May-21-14
The minerals Andesite and Phyllite in polarized light.
Andesite. 20x (2x obj. + 10x Future
Optics 5MP camera.)
Phyllite. 20x (2x obj. + 10x 5MP
camera lens.)
The specimens this month are thin slice
sections of Andesite and Phyllite.
As with all of my microscope photos, I look for
interesting shots to create prints, not for any
academic or research purpose.
At first glance, neither specimen looked
sensational, but Andesite at least showed
possibilities.
Photos with the 2x was not very impressive,
the turret was rotated to the 4x obj. and the
camera switched to a Canon 5D MkII.
What is Andesite?
Andesite is a fine-grained, extrusive igneous
rock composed mainly of plagioclase with
other minerals such as hornblende, pyroxene
and biotite.
A 4x obj. with the Canon 5D and a B&L 10x eyepiece, definite shapes and colours appear. The Canon 5D produces 21MP images
and the ability to make prints as large as A1+. Things are looking better.
Changing to a 15x eyepiece and 40x obj. gives an interesting shot at 600x, but perceived focus at 600x always looks a bit fuzzy.
Back to the 10x eyepiece, 10x obj. and a bit of stage rotation results in a nice image.
What is Phyllite?
Phyllite is a foliate metamorphic
rock that is made up mainly of
very fine-grained mica. The
surface of Phyllite is typically
lustrous and sometimes
wrinkled. It is intermediate in
grade between slate and schist.
At 40x, Phyllite as a photo subject leaves a
lot to be desired.
Inserting a clear cellophane filter above
the polarizer helps a bit, but not much.
The filter was rotated 45°.
At 150x defined patterns start to appear, but still not impressive patterns.
In the lower photo, the eyepiece was changed to 15x with the 40x obj. and distinctive patterns
pop up.
What Phyllite photos are really good for, is texture mapping in a 3D programme.
Using the Canon 5D with its
large sensor allows heavy
cropping to achieve some nice
Phyllite prints.
The photo is a blend of five
cropped shots with a cellophane
filter set to 70°. Each shot was at
a different focus depth.
The photos were blended with
the CombineZP macro, Pyramid
Weighted Average.
Mineral descriptions by Geology.com. Equipment: Labomed CxL LED monocular with the simple polarizing kit, Bausch & Lomb
microscope. Future Optics 5MP camera, Canon 5D MkII DSLR, HP Z420 WS. Capture software: Canon EOS Utility, ToupView 3.7.
Blending software, CombineZP, photo management, Adobe Lightroom, printer HP Designjet 130PS, 3D rendering Vue Esprit.
Carl Hennig. Kitchener, ON, Canada