About this image

The total solar eclipse of 31 July, 1981, photographed at Tarma, Siberia by a joint research team from the USA and USSR. Members of the team were R. Fisher and L. Lacy from the High Altitude Observatory of the National Center for Atmospheric Research, Boulder, Colorado and A.V. Bagrov from the Astronomical Council of the Academy of Sciences of the USSR, Moscow. This expedition was sponsored by the National Science Foundation of the USA and the Academy of Sciences of the USSR.

The photograph of the solar corona was taken with a camera system developed by Gordon A. Newkirk, Jr. This specialized instrument photographs the corona in red light, 6400 A -- through a radially graded filter that suppresses the bright inner corona in order to show the much fainter streamers of the outer corona in the same photograph.

Technical Information

Objective aperture: 11.1 cm
Focal length:       178 cm
Focal ration:       f/15

Film: Kodak Linagraph Shellburst (70mm)
Development D-76 (1:1): 8.5 min
Wavelength isolation filer:  Schott OG-3

Effective wavelength: 6400 A
Exposure:             24 seconds  (approximately)
Radial filter range:  104 in transmission.

Credit: High Altitude Observatory and Rhodes College