Photograph the Perseids Tonight

The annual Perseid meteor shower will peak the night of August 11. Members of the news media are presented with an excellent opportunity to witness and photograph the event.

The best views of the meteor shower will be from dark, rural locations. The darker the observing site, the easier it will be to observe or photograph the meteors. Most of the best sites in Southern California are in the desert and mountain areas located east of the major cities.

Meteor photography should not begin until it is completely dark, after 9 p.m. Early in the evening meteors will appear in the northeastern part of the sky. As the night progresses, the meteors will be more numerous and can appear anywhere in the sky. Most of the meteor shower activity will take place after midnight, when observers may see them at the rate of about one per minute.

Meteors occur at random times and locations in the sky. The best technique for capturing them photographically involves using a standard 35-mm camera that has a “B” or bulb setting. The camera needs to be securely fastened to a tripod. A cable release will allow for control the exposures with a minimum of vibration. Film with a speed of ISO 400, 800, or 1000 is recommended. Avoid using a telescope or a telephoto lens,because they reveal only a tiny fraction of the sky, thus greatly reducing your chances of catching a meteor. On the other hand, wide-angle lenses are more likely to catch a meteor, although the meteor will appear small on the photographic image. A 50mm lens is probably a good compromise.

To photograph the meteors, pick an area of the sky, focus on infinity and start the exposure. Those shooting with film may wish to hold the exposure until a meteor is captured, end the exposure, and then start another. Any interesting foreground objects in the shot can be nicely “painted in” to the picture with a flashlight beam shining on them. Don’t be afraid to experiment.

Photographers shooting digitally have some advantages and disadvantages over those shooting with film. Digital photography provides the photographer with rapid feedback as to how the exposures are going. However, it should be noted that for most digital cameras, longer exposures mean more noise in the image. This can be defeated by either taking short exposures (less than a minute) or taking a dark frame of the same length as your exposures of the sky. This dark frame can later be subtracted with a program such as Photoshop.

For anyone attempting to capture the meteor shower on video, the International Meteor Organization recommends using a fast lens and a powerful image intensifier. Specific details are online at http://www.imo.net/video/

Cloud-free skies are essential to having the best view of the meteor shower. The National Weather Service often does not provide the kind of forecast necessary for astronomical observations. A good choice is to check out the Clear Sky Clock. A list of all of the Clear Sky Clock sites in California can be found online at

http://cleardarksky.com/csk/prov/California_clocks.html

An explanation of how to read the data is provided on the web page. Simply choose a site close to where you will observe the meteor shower. Should clouds intervene, it is important to remember that the shower lasts for several nights, giving you another opportunity.

Original Source: Caltech News Release