Saturday, August 15, 2015

#Astrophotography: #Perseids #MeteorShower Over #SuburbanSkies and #LightPollution

A couple days ago was the peak of the annual Perseid meteor shower. It occurred on the night before the new moon, so the skies were extra dark, or less bright, depending where you live. The ideal way to watch a meteor shower is to go where the skies aren't so light-polluted by city lights, such as the mountains or the desert or an isolated beach.

I did none of the sort, trying to observe and photograph the light show over and under light-polluted suburban skies. This is my budget go-to setup for simple astrophotography, from the top down:

1. Kit zoom lens;
2. Inexpensive DSLR camera;
3. Cheap, programmable shutter release controller;
4. Decent camera mount (detachable tripod head with detachable mounting plate) to adjust camera angle;
5. Compass for Vixen Polarie, to more accurately find true north;
6. Vixen Polarie star tracking mount, to follow the skies for longer exposures;
7. Cheap, yet relatively stable tripod, with non-detachable tripod head and detachable mounting plate.

For this astrophotography session, I used the following settings:

1. Lens: 18mm, f/3.5, trying to manually focus to "infinity" without an infinity marking;
2. Camera: RAW+JPEG files, ISO 800 (I try not to go over 800 due to inexpensive DSLR noise), exposure time at BULB (a 30-second shutter would work, too);
3. Shutter release: 30-second exposure time, with a 10-second delay between shots, set to the maximum number of automatic shots;
4. Camera mount: Pointed Northeast, at the "love triangle" among the constellations Cassiopeia, Perseus, and Andromeda (mostly the Andromeda Galaxy);
5. Compass: Set for my latitude, with Magnetic North being a few degrees off True North;
6. Vixen Polarie: Star tracking mode, with Polaris (the North Star) in view of the viewfinder;
7. Tripod: All legs extended, as level as possible, pointed at the North Star.

I shot as much as I could that night, as this was mostly a "set it and forget it" deal, using a few batteries in the process. Focusing to "infinity" on a kit lens has always been a challenge. There were several awesome fireball-like meteors that were outside the camera's range -- to the West, Southwest, and Southeast. My camera was able to photograph five Perseid meteors, one (or two) unrelated "shooting stars," and a handful of airplanes flying overhead. The photo above was from a "developed" RAW file, but here are the results from unmodified (albeit cropped) JPEG files:

This is the same meteor as pictured above, the best one of the night. I could have called it a night after this one.
This is the second-best photograph of the night. You can trace the tail end of the Perseids to its radiant, which is coincidentally around the Double Cluster region in the constellation Perseus. The Double Cluster, of course, is light years away from Earth, but the Perseid radiant is just miles above us.
This faint Perseid is approaching the Andromeda Galaxy, so to speak. There is no way I could have seen this meteor as it happened.
The tripod and/or camera definitely vibrated during this shot, creating double images of stars. This meteor is pretty faint, and I did not see it with my own eyes at the time.
These two, parallel meteors are unrelated to the Perseids because their tails do not originate from the Double Cluster area of the sky, the radiant of the Perseid meteor shower.
This faint meteor is the last one photographed. The Perseid's light is virtually instantaneous in age, but the light from the Andromeda Galaxy (a little to the left of the meteor) is about 2.5 million years old.
Due to the number of "shooting stars," there were a lot of wishes to be made that night, and perhaps some of them will be granted.

No comments:

Post a Comment

Please note: Comments are open only for seven days after publication of each blog entry.