Bert P. Krages II
Attorney at Law | For more information, visit www.krages.com
1. A New View of the Universe
There are a lot of opportunities to incorporate astrophotography into standard genres such as nature and landscape photography. For the most part, the only significant limitation many serious photographers face with respect to astrophotography is not knowing about basic astronomy and how to expose film under dark conditions. Another misconception held by many photographers is that astrophotography requires expensive equipment. While some types of astrophotography require specialized equipment such as telescopes, motorized mounts, and guiding equipment, most can be done with standard photographic equipment. As is the case with most photography, knowing how to use one’s equipment to its full capacity is often more important than the equipment itself.
2. Basic Astronomy for Astronomers
This chapter covers the basic principles of astronomy that photographers need to know to image celestial bodies successfully. Starting with a description of the various types of celestial objects (e.g., stars, planets, nebulae, and galaxies), the text explains how to identify and locate them in the night sky. General guidance is provided on using tools, such as star maps, to find specific objects and using binoculars as a visual aid to locate objects that are too faint to find by unaided sight. Examples explain how to use easily identified constellations such as Ursa Major (the Big Dipper), Cassiopeia, and Orion as guideposts to locate some of the more notable celestial bodies, such as the Orion Nebula, Andromeda Galaxy, and Pleiades star cluster. In addition, specific guidance is provided on how to use tools such as compasses, software, and Internet databases to make very accurate predictions of alignments of celestial bodies with landscapes. This knowledge can be used to great effect to predict when and how bodies will be located in conjunction with terrestrial subjects.
3. Exposing the Night Sky
While there are special considerations in selecting and exposing film, the improvements in film technology over the last ten to fifteen years have made astrophotography feasible even for amateurs with basic equipment. Although film speed is a relevant factor, the more important concern is the capacity of a film to absorb light over extended exposure periods. Color sensitivity is another factor. Many celestial objects such as nebulae emit light in limited wavelengths, and the ability of individual films to record specific colors can be critical to producing good images.
4. Shooting the Moon and Sun
The moon is one of the most interesting of the celestial bodies to photograph. Not only does it vary in phase, intensity, and location; it also has visible surface detail that enhances its photographic appeal. It is also the only celestial body that can be photographed during the day or night. Techniques for photographing the Sun are described with regard to exposure, filtration, and safety.
5. The Night Sky with Camera and Tripod
This chapter covers the capabilities of the conventional camera and tripod as one of the most versatile setups for astrophotography. By varying the exposure, photographers can create images that render the night sky much as it is perceived by the naked eye, bring out stars and nebulae that cannot be perceived by the unaided eye, or display the motion of stars as semicircular trails. In addition to a discussion of exposure considerations, guidance is provided on techniques that maximize the kinds of images that can be produced with widefield photography. Specific guidance is provided on how to photograph meteors and comets.
6. Tracking and Telescope Techniques
If the camera is made to move in conjunction with the earth's rotation, extended exposures can be made that avoid star trailing and allow the film to record stars, nebulae, and other celestial bodies that are far too dim for the unaided eye to perceive. Tracking also allows colors to be recorded at much higher intensities than can be perceived with ordinary visual instruments such as telescopes and binoculars. The first part of this chapter discusses how to use tracking devices to eliminate star trailing in exposures lasting up to ten minutes. In addition, it describes how to build and operate a simple barn door tracker for those photographers interested in an inexpensive introduction to tracked photography. The next logical step after simple tracking devices is guided photography, where the camera is mounted on top of an equatorially-mounted telescope. By monitoring a guide star through the telescope, the photographer can adjust the tracking and achieve a high level of precision. Images can also be made using the optics of a telescope by connecting a camera body to the telescope with adapters. The basic types of amateur telescopes are described, along with their relative advantages and disadvantages for photographic use.