pairs of the moon
The earliest high
quality photographs of the moon are due to Warren de la
in the 1850's. His stereo pair of the moon, using the moon's libration
for the differing
perspective of the two views, is a spectacular example of early
scientific photography, astrophotography and stereo photography. Modern
methods have made some improvements to the quality and ease of
acquisition of the imagery, but capturing a good stereo pair of the
moon is still technically challenging.
(stereo pairs, cross-view)
Note that the libration axis, and there for the
orientation of the moon in the images lined up for stereo viewing, is
not the same for the different pairs.
Also note that these examples all show the moon at
its full phase. While using libration would apply at any phase, the
number of suitable opportunities is reduced because the axis of
libration is not in general aligned with the inclination of the solar
Also see Stereoscopic
Pictures of the Moon (Thomas
B. Greenslade, Jr., "The First Stereoscopic Pictures
of the Moon", Am. J. Phys., 40, 536-540 (1972) ), with examples of partial moon phases.
Stereo pairs of the moon could be acquired
simultaneously from the earth. If the photographers were separated by a
large fraction of the earth's diameter, say the 10,000 km between
[Hawaii and New York states], the parallax would be about 1/40 radian
(10,000 km divided by the 400,000 km distance to the moon), or a bit
more than 1 degree. This is somewhat smaller than the libration angles
used in these stereo pairs.
Libration of the moon
While we see primarily only one part of the moon's
surface because its rotation is tidally locked
to earth, its libration.
As the moon orbits the earth, it apparently rocks, about more than one
axis. This allows more than one perspective of the moon at different
parts of it's phase. If the phase is matched in two photographs at
different times (orbits), the libration angles are not necessarily
matched. The stereo photographs (above) use these different
perpectives, lining up the axis of the libration angle with vertical,
to mimic a stereo view of the moon.
This animation of photographs over a single orbit of the moon
shows both libration of the moon and a change in the moon's
apparent size, due to its varying distance from earth.
de la Rue photography and stereo photography
From Warren de
la Rue (Wikipedia, accessed 3/20/10)
Warren de la Rue was
the Son of Thomas De la Rue, the
founder of the large firm of stationers
of that name in London, Warren was born
in Guernsey. Having completed his
education in Paris, he entered his
father's business, but devoted his
leisure hours to chemical and electrical
researches, and between 1836 and 1848
published several papers on these
In 1840, Warren De la Rue enclosed a
platinum coil in a vacuum tube and
passed an electric current through it,
thus creating the world's first light
bulb. The design was based on the
concept that the high melting point of
platinum would allow it to operate at
high temperatures and that the evacuated
chamber would contain less gas molecules
to react with the platinum, improving
its longevity. Although it was an
efficient design, the cost of the
platinum made it impractical for
commercial use.
Attracted to astronomy by the influence
of James Nasmyth, he constructed in 1850
a 13-inch reflecting telescope, mounted
first at Canonbury, later at Cranford,
Middlesex, and with its aid executed
many drawings of the celestial bodies of
singular beauty and fidelity.
His chief title to fame, however, is
his pioneering work in the application
of the art of photography to
astronomical research. In 1851 his
attention was drawn to a daguerreotype
of the Moon by G. P. Bond, shown at the
great exhibition of that year. Excited
to emulation and employing the more
rapid wet-collodion process, he
succeeded before long in obtaining
exquisitely defined lunar pictures,
which remained unsurpassed until the
appearance of the Lewis Morris
Rutherfurd photographs in 1865.
In 1854 he turned his attention to
solar physics, and for the purpose of
obtaining a daily photographic
representation of the state of the solar
surface he devised the photoheliograph,
described in his report to the British
Association, On Celestial Photography in
England (1859), and in his Bakerian
Lecture (Phil. Trans. vol. clii. pp.
333–416). Regular work with this
instrument, inaugurated at Kew by De la
Rue in 1858, was carried on there for
fourteen years; and was continued at the
Royal Observatory, Greenwich, from 1873
to 1882. The results obtained in. the
years 1862–1866 were discussed in two
memoirs, entitled Researches on Solar
Physics, published by De la Rue, in
conjunction with Professor Balfour
Stewart and Mr B Loewy, in the Phil.
Trans. (vol. clix. pp. 1–110, and vol.
clx. pp. 389–496).
In 1860 De la Rue took the
photoheliograph to Spain for the purpose
of photographing the total solar eclipse
which occurred on 18 July of that year.
This expedition formed the subject of
the Bakerian Lecture already referred
to. The photographs obtained on that
occasion proved beyond doubt the solar
character of the prominences or red
flames, seen around the limb of the moon
during a solar eclipse. In 1873 De la
Rue gave up active work in astronomy,
and presented most of his astronomical
instruments to the university
observatory, Oxford. Subsequently, in
the year 1887, he provided the same
observatory with a 13-inch refractor to
enable it to take part in the
International Photographic Survey of the
of a New Optical Instrument Called the Stereotrope
of the Royal Society of London, Vol. 11, (1860 - 1862), pp.
[To Do: Transcribe.]
of the sun, the first images
[To Do: Transcribe a few of the good
photography and stereo photography
November 2006 and January 2007. (Source:
Canon 350D +
Barlow 2x + WO Megrez 960/80 (F/D 12.0) refractor, composite of 2
1/200 s on
November 2006 and January
2007, Quimper, France
Also see Laurent Laveder's analglyph of this lunar
Other stereo pairs by Laurent Laveder:
This Jupiter stereo pair, using the
planet's rotation, is extraordinary for showing atmospheric changes
that are manifested by anomolous disparity features.
Matheson's description (accessed 3/20/10):
"During the partial phases of a lunar
eclipse, part of the Moon is
inside the darkest portion of the Earth's shadow (the Umbra) and part
is outside it. The part in the Umbra is about 1000 times dimmer than
the part outside it. While our eyes can deal with that kind of
brightness range, computer monitors and prints can't display it. In
order to produce an image that approximates what the eye sees, I
combined eight exposures ranging from 1/2 second to 1/320 second. The
eight images were taken over the course of a few seconds at 11:11 p.m.
EST while the Moon was emerging from the Earth's shadow.
Partial phase: 2008-02-20 11:11 p.m.
EST from northern New Jersey.
Composite of 1/320, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8, and 1/2 second
exposures at 800 ASA with Canon 40D through Astro-Physics 155 at f7."
Comments are welcome (dow[at]uoregon.edu).