Comet NEOWISE pictures are being posted from around the world as it appears in the night sky, and Nanaimo’s astral shooters are producing a substantial portfolio of locally made comet images.
Some are stunning and created by photographers with sophisticated equipment and years of experience in astrophotography, while others are struggling to catch images of the comet before it moves along on its 6,800-year orbital journey around our solar system.
For those frustrated by early attempts to capture NEOWISE on camera, Tony Puerzer, Nanaimo Astronomy Society vice-president, says sophisticated camera and telescopic equipment aren’t needed to create quality comet images.
Even the latest model smartphones, with night mode photography settings, can capture an image of the comet, but Puerzer recommends an entry-level digital single lens reflex camera, with an inexpensive 50 millimetre focal length lens as the best starting point to create clear, sharp comet images.
“You want even an inexpensive DSLR and something to put it on, be it a tripod or a fence post or something that will hold it steady,” Puerzer said. “Because you’re not tracking it with a [star tracking] telescope mount, you’ll be limited in the time you have to shoot.”
Because the Earth is spinning at about 1,600 kilometres per hour, exposure times of longer than a few seconds will cause stars in the final image to appear as streaks, or trails of light that become longer as exposure time increases and objects, such as comets, will appear blurred. Telescopes designed for astrophotography have special tracking mounts that compensate for the rotation of the Earth and prevent star trails.
A workaround for lack of a tracking mount is to use a “fast” camera lens, with an large aperture that allows more light to pass through to the camera’s sensor, thereby shortening the exposure time. Most camera manufacturers offer relatively inexpensive 50mm fixed focal length lenses, which have a large maximum aperture of about f/1.8.
“If you had a 50mm lens – a nice fast 50 would be ideal – like a Canon camera or a Nikon with a nifty 50, that would be [awesome]. That would be the lowest cost, best thing, but then you’re limited to maybe six or eight seconds before the stars start trailing because everything’s turning,” Puerzer said.
A wider view angle 28mm lens can allow for longer exposures before star trails become apparent, but the lens’ magnification will be about half that of a 50mm lens so the comet image will appear smaller.
To shorten exposure times even more, Puerzer recommends increasing the camera’s ISO (light sensitivity) setting to a higher sensitivity.
“Just crank her up and you’re looking at maybe 10 seconds for the picture, so the stars don’t trail,” he said.
Finally, Puerzer recommends focusing manually, instead of using the camera’s automatic focusing system, to make the stars appear sharp in the viewfinder, which will also bring Comet NEOWISE sharply into focus.
“That’s basically it,” Puerzer said. “You’ve got a fast lens, high ISO and then the shutter speed is really limited because the sky is turning … and that should get you something. That’s your recipe.”
Puerzer said NEOWISE is currently moving away from the sun, but coming closer to the Earth, which might make it appear dimmer, but larger before it disappears from the night skies by about the end of July, so there are still plenty of opportunities to capture images.
The comet appears low above the horizon in the northern sky from early evening to dawn, but viewing is best when it becomes dark enough for the stars to appear and in areas where there is little or no artificial light pollution. Jack Point, Neck Point and Pipers Lagoon parks can be good options, or anywhere there is a clear view to the northern horizon. Puerzer said he’s had good views from Wheatcroft Park, near Pipers Lagoon Park.
Anyone who would like to share the results of their efforts to photograph the comet is also welcome to post their images on Nanaimo Astronomy Society’s Facebook page at www.facebook.com/groups/nanaimoastronomy/.
“There’s tons of people who aren’t [Nanaimo Astronomy Society] members that are on the group,” Puerzer said.