Star gazing at Westmoreland State Park by Matt Asai
During the weekend of March 5, 2011, I was scheduled to teach Nature Photography at Westmoreland, Belle Isle and Caledon. Because March 4 was the start of the new moon, I decided to take some star trail pictures at Westmoreland. The best time to photograph star trails is during the new moon phase of the lunar cycle because if the moon is showing it will washout the stars in an extended exposure. It is also best to take the pictures where there are no surrounding lights.
Matt Asai teaching photography class at Westmoreland State Park!
I must confess that I broke the cardinal rule of digital photography – I failed to charge my batteries the day before I left for Westmoreland. One of the batteries was DOA and I put it in the charger as soon as I got to my cabin at Westmoreland. I was hoping the second battery would suffice. I decided that I would go down to the river where I would have an unobscured view of the North Star and the pier. I did a test shot and it was a little over exposed, so I adjusted for a shorter exposure than the test shot indicated. However, two minutes into the planned half hour exposure the battery died – back to the cabin with one test shot in the camera.
Generally, the battery charger takes about 4-6 hours to recharge a battery. Finally by 1:30 a.m. the battery was recharged. I had to take the pictures that night because the forecast for Saturday night was for cloudy skies, making it impossible to do star trails. Because the lights on the Maryland side of the river were producing too much light, I decided to move to the field near Murphy Hall. I did several test shots and one half hour shot. I think I finished up at 3 am.
To do a star trail where the stars rotate around the North Star, you should have a relatively clear view of the North Star. You can view prospective places to shoot by looking toward the north and imagining how the night sky will look in your picture. At night, you can do a test shot – you push your DSLR’s ISO to 6400, shoot for a minute at around f/8 (wider if you want brighter star trails), make your adjustment with the shutter speed. Whatever shutter speed gives you the exposure you’re looking for, you then change the ISO to 100 and multiply the shutter speed by 64. You will need to use your bulb setting on your DSLR and a cable release or equivalent (or hold your shutter release for the entire extended exposure).
Star Trail over the Potomac River from Westmoreland State Park
If you don’t have a DSLR or you don’t have a cable release or don’t want to do an extremely long exposure, you can do a series of tripod shots during the course of the night and then merge the photographs in Photoshop or a shareware program like Image Stacker.
Belle Isle State Park and Caledon Natural Area when the Astronomy Club is there, you can do the star trail pictures when and where they meet. Call Ranger Sammy and he’ll give you details on when the Astronomy club meets at Caledon.