Nearest Star: The Surprising Science of our Sun by Leon Golub & Jay M. Pasachoff

Nearest Star: The Surprising Science of our Sun by Leon Golub & Jay M. Pasachoff

Author:Leon Golub & Jay M. Pasachoff [Golub, Leon]
Language: eng
Format: epub
ISBN: 9781107672642
Publisher: Cambridge University Press
Published: 2014-02-17T00:00:00+00:00


FIGURE 5.8. Solar eclipse composite images made from dozens of original photographs combined to bring out the full range of bright and faint features in the corona. The computer work to composite many individual frames to make each of these composites was carried out by the New York amateur astronomer Wendy Carlos from individual frames taken at Williams College expeditions. (a) Aug. 11, 1999; (b) June 21, 2001; (c) Dec. 4, 2002; (d) March 29, 2006; (e) Aug. 1, 2008; (f) July 22, 2009; (g) July 1, 2010; (h) November 14, 2012.

Through that decade, film became replaced by electronic detectors in much of astronomy, and eclipse photography was no exception. Most of the detectors are of a type called charge-coupled devices, or CCDs. Even the camcorder you may see advertised in your newspaper or online has a CCD in it, though the ones professional astronomers use are more carefully made as well as being more precisely calibrated and being more controllable in exposure time and other functions. CMOS chips (Complementary Metal Oxide Semiconductor chips) are now also in use for cameras. Many people now take eclipse photos using merely their iPhones, though those are wide-angle views. (Some of us are organizing a “Megamovie” project, http://www.eclipsemegamovie.org, with iPhones and other cameras for the U.S. eclipse of 2017.)

Many people now make videos of eclipses, using their CCD camcorders or the video function on their cameras or phones. Standard, consumer cameras usually have zoom lenses so powerful that the corona can be made to sufficiently fill the frame. A hint is to focus the camera manually in advance, since otherwise the automatic focus feature may “hunt” back and forth, losing valuable time in the all-too-brief total phase of the eclipse.

Note that only during totality, from diamond ring to diamond ring, can you look at the Sun directly or can the camera image the Sun directly. Before second contact or after third contact – that is, during the partial phases – you need to use special solar filters to reduce the intensity of the solar photosphere to safe levels for your eye or for your camera.

So the routine for taking photographs of an eclipse is to have the filters in front of your camera lens until the diamond ring appears, and then to take it off for the interval of totality. It must then go on when the second diamond ring appears. Just how well you handle that timing affects how good your eclipse video will be.



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