Beginners Astrophotography

So, you're looking to get into astrophotography but don't want to spend an arm and a leg (or the equivalent of a tank of gas) and just want to use the camera you have?  Well, there's three targets you should consider, the moon, star trails, and aurora.  The easiest of course is the moon, if you have a good lens, just about any size will do, and a well composed foreground, then it's pretty easy, put the camera on a tripod and bracket your exposures.  What does that mean?  To bracket your exposures mean you try lots of different exposure times, in my experience, a crescent moon with an f/4 lens requires about 1 second, a full moon with the same lens requires about 1/125th of a second.  Here's a shot I took of a setting crescent moon in the western hills of Maine with an 85mm lens:

Not much to it, sometimes you just need to find the right target.

Next up is star trails, all you need is a camera that can do long exposure photography, a lens, a tripod and a shutter cable.  Star trails are rather cool, because if done well, you can get a very good appreciation for the movement of the heavens in any given evening as well as the different star colors out there.  In order to do star trails, you will need to find a very dark location, ambient light will completely ruin a star trail shot as you will need to do very long exposures, typically at least an hour.  Oh, this goes without saying, most modern Digital SLRs are just not capable of taking hour long exposures, so go with film, 400 speed is the best for this application in my opinion.  OK, so you found a dark location, the most dramatic star trails are those that show the motion of the stars moving around the north star, aka polaris.  But John!  I have no idea where polaris is!  No problem, try this little trick, find the big dipper (if you can't find that, well... I don't think I can help you), the last two stars in the "cup" part of the dipper, if you draw a straight line that goes through the two stars then about two fist widths (held at arms length) you'll find another bright star, that's polaris.  Anyway, point the camera on a tripod with an approximately 50mm lens at f/16 or so, put the camera on bulb and hit the shutter cable, come back in about an hour, you'll be surprised at your results.  Here's a 4 hour star trail I took back in 2003:

You can see the motion of the stars around a central star (polaris) unfortunately, that darn tree blocks the view of polaris!  Anyway, you get the idea, no telescope no mount no guidance system necessary, just very dark skies and a FILM SLR that can do long exposure photography.  Make sure you stop down the lens to f/16 or so, that way you won't flood out the image with too much light.

Finally, everyone's favorite target... aurora.  I'm willing to guess that most of you who are reading this have never seen an aurora.  Count me among those until one brilliant night, sept 7th 2002, I was up in central Maine with my telescopes waiting for nightfall when it just kept getting brighter and brighter rather than darker, and lo and behold, the heavens just erupted in green and pink streamers that lasted off and on through to 2:00am the next morning, truly an evening to remember!  A little bit of a digression here, believe it or not, aurora are actually semi-predictable, please visit SpaceWeather.com for 1-2 day predictions.  Unfortunately, they're not all that accurate and also unfortunately, we're currently at the solar minimum, the bottom of the 11 year sunspot cycle.  Typically, aurora's happen as the result of solar flares, which also typically happen as the result of high sunspot activity, in other words, for 2006, we're probably not going to see many of them at mid latitudes.  However, they do happen unexpectedly on occasion.  Enough John!  How do I photograph them?  Fortunately, this is a no brainer, but you actually need to be ready... have a sight prepared, you need to have a clear view of the northern skies and it needs to be light pollution free.  If you get that, then you'll get some photos worthy of an 8x10 on your favorite wall.  They're simple enough to photograph, when an aurora erupts (once again, visit spaceweather.com frequently, also, they offer a $5/month subscription service) just put your SLR with 400 speed film, or DSLR at ISO 800 with a wide angle lens and snap off 30-60 second exposures.  Not much more to it than that!  On the night before halloween, 2003, this aurora erupted illuminating the skies of Bedford, NH on a night that nobody who viewed it will soon forget:

These two photos were both 30 second exposures with a 1970's style olympus OM-1 and 400 speed film.  Not bad for archaic technology!  Of course, the secret to great aurora photography, is being in the right place at the right time, no easy task, but spaceweather.com can help in a big way.  BTW, for you perpetually curious, the colors of an aurora are the result of what gasses are being energized (ionized, with an electron being ejected resulting in a photon, i.e. a particle of light).  Hydrogen releases red, oxygen, blue, carbon, green, I think I got that right... feel free to correct me if I got that wrong.

Comments

[Donna Baker]

Hi John,

I just showed this pictire to my family, because of the date. We also saw this one in Rochester NH. That was the night that the kids there, go trick or treating, the night before Halloween. My oldest daughter didn't know what it was and got scared until, her father calmed her down and told her. Three years later, you have the pictures from a different part of NH! Amazing! Your pictures are great!

[Todd Gross]

He did this in a short period of time, short learning curve showing it is possible for folks to get THIS good in a hurry!

[John Lanoue]

Thanks Donna! The night I took these photos, my daughters were already in there pj's for the night, but I rushed them into the minivan and headed up to a local farm. It was pretty funny when a police officer came by wondering what I was doing and noticed my kids strolling around the farmland with bare feet & pjs, at least the kids didn't end up in protective custody ;-)