Evening star. [volume] (Washington, D.C.) 1854-1972, 1900-05-15
Interest Everywhere in the Approach
ing Phenomenon.
ARRANGEMENTS FOR SECURING VIEWS
Good Opportunity for Display Of
Amateur Photographic Skill.
THE BELT OF TOTALITY

Are you going to try a shot at the
eclipse?'
This is the uppermost question in anna
teur Photographic circles throughout and
adjacent to- the belt of totality of the COM
ing total observation of the sun, which oc-
ours Monday. May 2s. Here, in Washing
ton. the eclipse will be almost total, and
only thin crescent of the shining orb will
be visible at this period of the phase. With
a triple-coated non hallation plate and an
exceptionally rapid exposure compare
lively good and quite valuable picture OF
the phenomenon may be secured.
Local devotees of the camera may take
assurance from the fact that the govern
ment has constructed two immense cam
eras in this city for photographing the
eclipse in its Washington phase. The stay
at home viewers of the eclipse therefore
may feel justified in making arrangements
themselves to have flash at the pass
ing celestial show, knowing they will nave
the same opportunity for results offered
the federal cameras constructed here In
the capital.
On the other hand there are many Wash
ington amateurs who are going to take ad-
vantage of the cheap rates offered by the
railroads and journey to some point along
the belt of totality, which stretches from
New Orleans northeasterly to Nor1oik. Va
where it passes out upon the Atlantic A
majority will naturally gather in the Nlcln-
ity of Norfolk. that point Offering the best
advantages and conveniences Of any OF the
nearby localities included within the line
of absolute disbursement The excursion
to be made to Norfolk by the National
Geographic Society means that hundreds OF
Washington cameras will be pointed To-
ward old Soils customary position in the
sky where, however, instead or the usaal
brilliant, burning ball, will hang dark
sphere. surrounded by an enulgence OF
N
in the character of Its spreading rays, the
aurora.
The Spectacular Feature.
The amateur will naturally seek only for
the spectacular feature of the phenomenon
which will be the corona just mentioned
The scientists will sacrifice, by longer ex-
posure, the corona. that they may secure
the longer rays stretching far beyond the
brilliant, jagged circle of light, and may
also record an impression OF the smalier
celestial objects surrounding the sun. DIS
cernihle only when the dazzling brilliance
of the orb is shaded in eclipse by the
moon.
With the high degree of perfection now
attained in photography, the Supersensi-
tive Photographic plates will, with the aid
of the powerful lenses now possible, take
an image invisible to the eye even through
most powerful telescope. II is AN IN
doubted fact that photography Will be
more of a feature in the observance or the
coming eclipse than ever before Parties
of scientists have been equipped by various
institutions and through private capltal,
with the most expensive outfits, the cam,
era in its telescope form being considered
of vast Importance .
Amateurs are perhaps the more interest
ed in the coming eclipse by reason OF the re.
corded fact that the best photograph OF
the eclipse in India in 1895 was obtained
by an amateur with a homemade camera.
His views of the phenomenon We're &C
!, .-rtav ir q
~. world IN preference to those made by
professionals with larger and superior IN
struments.
Washington camera workers are primarily
Interested In photographing the partial
phase of the eclipse. which will be visible
in Thu, city 1t is estimated that at least
eleven-twelfths of the surface or the ORD
will be cbscurcd to observers In thls 10
ca,itv. About the almost total phase Will
be many of the features of the total eclipse.
A non-hallation plate must necessarily De
used, however, to prevent & Dur OF Hsht
from The rim of visible sun. The exposure
must also he an instantaneous one of the
supreme rapidity permitted by the shutter,
with the smallest diaphragm opening The
value OF a view of the partial phase is
small. however, owing TO the fact that
excellent views of the beautiful corona
anent a total disbursement will probably be
most plentiful
Many Weird Results.
Therefore 1t would be advisable for the
local manipulators of the camera to contine
their efforts to the grotesquc and exception
ally Interesting effects produced upon earth
" objects The peculiar diffusion of the
light when the eclipse is almost total tends
to many weird results. The most notice
able of these will be the half-moon spots
thrown upon the ground wherever the rays
force their way through the foliage OF
trees Often objects are streaked with pc
c,,liar light The close observers will find
many interesting things to photograph our
ing the prevalence of the shadow. The eN-
posures in these instances should be the
same as would govern the photographer
under ordinary conditions.
In Washington the eclipse will begin at
7:Sj O'Clock ard end shortly after 10 in
tho morning. The period Of greatest to-
tnlity will be reached at about 500 CLOCK.
For photographing the eclipse IT 1s adV1s-
able of course and practically necessary,
that the tele-photo lens shall be used, else
the object of the sun Will appear as out a
dot upon the plate 1t is estimated that
with a tele-photo lens the diameter or the
main boGv of the sun impression upon the
plate will be one one-hundredth of an inch
to each inch of focus; hence with camera
of twenty inches focal length picture or
the sun one-fifth of an inch IN diameter
will be obtained. The diameter of the sur
rounding aurora corona will be four
times as great. or four-ffths or an men In
diameter. The large cameras eTtcteu III
the United States naval observatory.
Georgetown Heights, and at the Smithson-
ian Institution have focal length of about
twenty feet, SO it will be seen that pic
ture of the partial eclipse about two and
one-half inches in diameter will be secured.
The various parties sent out by the naval
observatory. under the general direction OF
Prof Brown, and by the Smithsonian In
stitution, under Prof. Langley. will erect
like cameras in the path of the total
eclipse and expect to secure pictures of the
corona nearly ten inches in diameter. These
large cameras will be used mainly for pho
tographng the corona, comparatively
smaller Instruments being employed for the
long rays.
Duration of Exposure.
To secure a good picture OF the corona
the exposure with a medium diaphragm
stop should be between two and three sec
onds The camera should be rigidly fixed
and a plate of normal senstiveness used
An excellent focus may be had by bringing
the camera to bear upon well-defined OBJ
ject quarter. half a mile away. The
Image should be brought out as clearly as
possible.
For the long rays an exposure of from
2Oo to 800 seconds will be required on a nom
hallation triple-coated plate. To secure
these views a camera trained by clock
mechanism to follow the sun will be neces-