Posted by: David Vernon | October 21, 2009

A Meteoric Rise

Working OT - Tremont Grain Co-Op

Well that was unexpected – but not entirely unexpected.

Between hosting houseguests and gearing up for the start of fall classes at the Peoria Art Guild (the above picture taken after a late-night cemetery session with the No-Light/Low-Light class last Saturday), I took a little six-day vacation from the CIPB. And for that I rejoice apologize. Actually I did kind of miss you guys – just a little.

So who was up at 3am for the Orionid meteor shower this morning? Hmmm? Meteor showers are not that tough to photograph but they are tough to photograph well. Unfortunately a ton of skill doesn’t help much – but being prepared does. Ever wondered what a meteor shower is? Meteor showers exist because of comets. Comets pass through the solar system on their huge elliptical orbits around the sun and they shed debris as the go. Once a year the Earth passes through that same spot and gets showered with little bits of debris in the form of meteors. A meteor shower is named after the constellation of stars that the debris appears to come from. In reality it’s not coming from that constellation but if you drew a straight line from earth through the comet debris, the constellation in question would be at the other end of the line. So the term “Orionid” – for the current showers – means literally “from” Orion or “out of” Orion.

So what’s the problem? Why is it so tough to make good photographs of meteor showers? First of all – these aren’t blazing trails of light that make the moon look pale. A typical meteor entering the atmosphere will be seen for just a few seconds as a streak of light not much brighter then a good magnitude star. If you’re not quick and you’re not looking you can easily miss it. Secondly, just because the come “out of” a constellation, they don’t just appear around the constellation. The meteor trails can simply be traced back TO the constellation, but can appear anywhere in the sky. And thirdly, this isn’t a firestorm of meteors. The best meteor showers still only produce about one trail per minute and not every trail is guaranteed to be a good one. Patience is key.

So how do you maximize your opportunity? Okay – your best weapon to capture these elusive trails is to find somewhere dark. Really dark. So if you’re in a moon phase where the moon is relatively bright, you might want to wait until the moon is out of the picture. And if the wilderness of Nevada isn’t an option tonight, at least get out of town and into the country. And finding a spot with some nice tree cover helps shield your field of view from the lights of say Peoria, Bloomington/Normal, Champaign/Urbana, or Springfield. Right now we’re just four days past the new moon so it is relatively dark still.

The next step? Frame up your shot to cover as much of the sky as you can. Leave the telephoto lens at home and go wide – as wide as you reasonably can. I say that because super wide makes everything look small and further away. A fish-eye may not be the best choice – but you never know until you try. And consider where you point your camera. Pointing your lens at the star Polaris (the North Star) gives you circular star trails and also gives you meteor trails that run across the scene – making it easy to pick them out.

Then the key is optimizing your camera’s settings to maximize your few seconds of star trail. You want a decently long exposure – at least two minutes and it’s reasonable to assume 8-15 minutes as a choice to let you capture a couple trails. The awesome exposure value chart tells us we’re looking at values between -6 and -2 (little moon to more moon). For an 8-15 minute exposure at ISO 100 this means an aperture between f/4 and f/8. But here’s the thing. You want to be a little more light sensitive. You want that 2-4 seconds of meteor trail to leave an impact. The long exposure just means you’re going to capture more trails – it doesn’t mean the trails are going to be any good. So go up to at least an ISO of 400. This makes the brief star trail appear four times brighter then at 100 ISO. And don’t forget to compensate for those two stops by moving your aperture down a bit to keep you between 8-15 minutes. That at least gets you started. You’ll also need to make a decision about long-exposure noise reduction. I’d say start with it off and see how bad it gets with fixed pattern noise/hot pixels. If you see a lot of them you can choose to turn on the NR and double your true exposure time – or you can fix it in post. I just hope a meteor trail and a hot pixel don’t miss.

To busy to worry about the Orionids? Check out this list of the best annual showers and start making plans. The Perseids will be back in ten months – giving you great numbers and WARM nights.

  • Early January:  Quadrantids Meteor Shower. The Quadrantids are an above average shower, with up to 40 meteors per hour at their peak.
  • Mid April:  Lyrids Meteor Shower. The Lyrids are an average shower, usually producing about 20 meteors per hour at their peak.
  • Early May:  Eta Aquarids Meteor Shower. The Eta Aquarids are a light shower, usually producing about 10 meteors per hour at their peak.
  • Early August:  Perseids Meteor Shower. The Perseids is one of the best meteor showers to observe, producing up to 60 meteors per hour at their peak.
  • Mid October:  Orionids Meteor Shower. The Orionids is an average shower producing about 20 meteors per hour at their peak.
  • Mid November:  Leonids Meteor Shower. The Leonids is one of the better meteor showers to observe, producing an average of 40 meteors per hour at their peak.
  • Mid December:  Geminids Meteor Shower. Considered by many to be the best meteor shower in the heavens, the Geminids are known for producing up to 60 multicolored meteors per hour at their peak. Of course there is the Brrrr! factor to consider…
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Responses

  1. Just take your camera, aim it at the stars, 1 second exposure, and jerk the camera slightly while the shutter is open, and presto….lots of meteors!!!

  2. […] to do a one-hour exposure, for example, you really open yourself up to fixed-pattern noise – something we covered a few weeks ago. Now you can deal rather easily with that noise by using your camera’s long-exposure noise […]

  3. David,

    I’m glad I stumbled upon this blog post. I appreciate the tips on aperture/ISO, I’m a beginning photographer with my first DSLR and hoping to get some shots of the geminid meteor shower over the next week – your advice will definitely come in useful.

    By the way, I was looking at your website and saw that you live in Delavan, IL. I actually live in Emden. Small world, eh? I just hope all this snow/rain we’re supposed to get doesn’t kill my meteor hopes =(

    Thanks,
    Drew


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