Comets - Bill Kramer

Photography * Sample Images

Comets are rare visitors to our sky that appear as ghostly streaks or dashes across the heavens. Sometimes a comet's tail can extend a long distance from the head of the comet and it gives the appearance of something zooming past. Unlike meteors, comets do not zip past but hang in the sky. To the naked eye they do not appear to move unless observed over a succession of nights. When watched carefully for a series of days a comet will visibly move against the back ground stars.

Comets are best seen and photographed from very dark locations where the night sky is full of stars and the Milky Way shines clearly. The head of a comet will appear as bright as a star. It will appear fuzzy though. And in one direction, the fuzz will continue deeper into the sky than in other directions. The fuzzy offshoot, known as the comet tail, will point away from the Sun. The further away from the head of the comet, the dimmer it will appear.

Through a telescope, the comet tail is visible against the background stars. Being in a dark site is important to really see any detail. Another thing to look for with a telescope is the shock wave in the front. The light will rapidly diminish and a good telescope at high power will reveal interesting details that a photograph does not capture.

But the best way to observer a comet is with a good pair of binoculars, someplace that it is very dark.

Recommended reading...

Learn more about Comets - a scientific approach teaches about the chemistry of comets.

Comet Photography

Photographing a comet is easy. Getting an excellent photograph of a comet is not. Ted and I learned this by burning up lots of rolls of film. Fortunately, we had two marvelous comets appear in the late 1990's providing us with lots of practice. It was a most excellent time!

Here are some tips.

Make sure you are using a good dark site. That is, no extra lighting nearby and minimal sky fog or background lighting.
The camera needs to be mounted so that it is tracking the stars. An equatorial mount is best and required if you are using a focal length longer than 300 mm for the lens.
Mounting the camera on the telescope in a piggyback fashion worked best. While the image was being exposed, the comet is held in the center of the telescope eyepiece.
A focal length of 200 mm to 300 mm is perfect for catching the tail amongst the back ground.
Shorter focal lengths of 50 to 100 mm are great for long tails and showing comets relative to bright stars.
Pick a night when the moon will not interfere with the longer exposures.
The best results obtained to date are with films of higher speeds such as 400 and 800 ASA.
For long exposures that are tracking, do not include foreground objects.
Include foreground for wider angle images and do not track the comet with the camera, allow it to trail.
Long focal length photograph through a telescope requires fast film and long exposures that will over expose the coma (head).

Comet photography does not require a lot of equipment. You can have a lot of fun with a camera, a tripod, and a very dark location. The comet and star trails will produce interesting images and when combined with foreground objects can be considered quite artistic.

Example Images

2007 Comet 17P/Holmes - Comet 17P/Holmes was one of the strangest comets I've ever seen. It was cloudy in Ohio for over a week and it was reported to be gaining brightness. On the night of the 28th we had great sky conditions and I took images using the Canon Digital Rebel with 100-400 zoom mounted on an EQ-2 drive. The comet does not appear to have a tail but is instead a large ball of dust with a bright center. To the naked eye it appears as a new star about the same brightness as Polaris. In a telescope it was a round ball of glowing dust/gas with a bright center dot.

October 28, 2007 - Dublin, OH - 100mm, 10 seconds, Canon Digital Rebel

October 28, 2007 - Dublin, OH - 400mm, 15 seconds, Canon Digital Rebel

2002 - Comet Ikeya-Zhang (for details click - http://encke.jpl.nasa.gov/)

March 16, CAS dark sky site - 300 mm, 3 minutes, using Fuji 800 film, mounted piggy back on Questar. New moon was just a few degrees away as a bright crescent. That fogged the image somewhat.

Click on these (and others below) for more pictures.
(closer view 400x400) (another exposure - 3 minutes 600x400)

March 22, Perkins Observatory (front lawn) - 70mm, 2 minutes, no tracking.

1997 - Comet Hale Bopp (for details click - http://www.jpl.nasa.gov/comet/)

Comet body visible and shock wave - Meade 10" f/6.3 - 5 minute exposure with Fuji 1600

200 mm lens piggy backed on Questar - 3min - Fuji 800
200 mm lens piggy backed on Questar - 10 minutes - Kodak 400
50mm, Meade 10" in foreground, 3 minute exposure

1996 - Comet Hyakutake (for details click - http://www.jpl.nasa.gov/comet/hyakutake/)
This comet was a very fast moving comet that traveled through the northern sky past the north star. It's position and proximity to Earth made for some excellent images. But it moved by quickly and there were few clear nights to work with. However, there was one bodatiously clear evening in which we managed to get this image.

Comet Hyakutake taken with 200 mm lens piggy backed on Questar - 3min

Recommended reading...

A more casual look at comets with Dr Sagan and Ann Druyan. A very excellent book!

Return to Bill & Ted's Excellent Astrophotography Page
(c)2002-2007 Bill Kramer