![]() ![]() ![]() For a few brief minutes or seconds, the Sun's Haze or clouds interferes on eclipse day.Ĭertainly the most spectacular and awe inspiring phase of theĮclipse is totality. Bracketing by several stops may also be necessary if So no exposure compensation is necessary except for the narrowĬrescent phases which may require two more stops due to solar limbĭarkening. Sun's surface brightness remains constant throughout the eclipse, After the film is developed, note the bestĮxposures and use them to photograph all the partial phases. Shoot a roll of film of the mid-day Sun at aįixed aperture (f/8 to f/16) using every shutter speed betweenġ/1000 and 1/4 second. The correct exposure is accomplished by running a calibration test Low to medium speed film is recommended (ISO 50 to 100) since the However, theĪctual filter factor and choice of ISO film speed will playĬritical roles in determining the correct photographic exposure. Visible and infrared energy by a factor of 100,000. These filters typically attenuate the Sun's An abbreviated list of solar filter manufactureres is alsoĪvailable online. Manufacturers and dealers listed in Sky & Telescope andĪstronomy magazines. Such filters are most easily obtained through Throughout the partial phases for both photography and safe For any particular focal length, the diameter of the Sun's image is approximately equal to the focal length divided by 109 (Table 1).Ī mylar or glass solar filter must be used on the lens However, a focal length of 1000 mm requires less critical framing and can capture some of the longer coronal streamers. In order to photograph the Sun's corona during totality, the focal length should be no longer than 1500 mm to 1800 mm (for 35 mm equipment). Longer focal lengths permit photography of only a magnified portion of the Sun's disk. However, since most cameras don't show the full extent of the image in their viewfinders, a more practical limit is about 2000 mm. If full disk photography of partial phases on 35 mm format is planned, the focal length of the optics must not exceed 2600 mm. Focal lengths in excess of 1000 mm usually fall within the realm of amateur telescopes. With one solar radius of corona on either side, an eclipse view during totality will cover 9.2 mm.ÊAdding a 2x tele-converter will produce a 1000 mm focal length, which doubles the Sun's size to 9.2 mm. The focal length of 500 mm is most common among such mirror lenses and yields a solar image of 4.6 mm. A better choice would be one of the small, compact catadioptic or mirror lenses that have become widely available in the past ten years. A standard 50 mm lens yields a minuscule 0.5 mm image, while a 200 mm telephoto or zoom produces a 1.9 mm image. However, a lens with a fairly long focal length is recommended to produce as large an image of the Sun as possible. Almost any kind of camera with manual controls can be used to capture this rare event. Solar eclipses may be easily photographed provided that basic eye safety precautions are followed. Adapted from NASA RP 1383 Total Solar Eclipse of 1998 February 26, April 1996, p. ![]()
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