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We Are Always Tweaking

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Original Publish Date: 12-November-2015
Last Revision: 12-November-2015

When we get questions on our older columns, we often answer them directly and update the articles to reflect new information. For example, when we originally published our three part series on Finding and Photographing the Milky Way we had no clue they would be our most read articles. Over time we added more charts, and tables, including a table listing when the best time is to spot the Milky Way – alas, not October through February.

The Milky Way Series

Pointy Land
The articles in the Milky Way series are:

Meteors and Meteor Showers

Celestial Slasher [C_224-9234]

We have also made periodic updates to our articles on photographing meteors and meteor showers.  We point this out because the best shower of the year is the Geminids and that shower occurs December 12-14.  Start planning right now!

To help you out, we have begun adding “Original Publish Dates” and “Last Revised” dates to our articles.  Of course most of the principles we have written about are timeless.

Meteor Hunting

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I thought the evening was a disaster. I got to bed at 10 pm. Set the alarm for midnight. Got up and saw that the clouds were impenetrable at my home near Los Gatos, California. With a sigh I finished packing up my equipment and set out toward the place I had picked days before.  It was a private home with an open lot and a great view of the Diablo Mountain Range.  The owners had agreed to let me arrive at midnight and remain until about 5 am. BUT when I arrived I couldn’t see the stars or the mountains. Darn.

I know that sometimes the mountains east of the San Francisco Bay Area block the low clouds from advancing inland, so I continued on. Sure enough I noticed from the freeway that I could actually see a huge hole in the sky. Astronomers call them “sucker holes” because they sucker you in to thinking its worth setting up equipment.  I had to find a way to turn around on the freeway and find an off-freeway road with a decent view.  Finding such a place took about 20 minutes, and by the time I arrived, thick clouds had enveloped the eastern sky, but at least I could sometimes make out stars to the north, including the all important Polaris.

I set up and aligned my Polarie, and started the automatic timer to take continuous 44 second exposures (2000 ISO) starting at 1:28 AM. I figured, the clouds were sometimes thin enough that I might capture a meteor through them – after all, once in a while I could make out where the bright planet Jupiter was.  Time passed and I huddled in my car with what seemed like 20 layers of clothes. I had forgotten my pillow and my sleeping bag and didn’t have my customary thermos of hot chai. The night was cold, breezy and a little damp so the shelter of the car was essential.  I slept fitfully. Each time I awoke I saw thick clouds. From 2:16 to 2:23 the clouds seemed like they were going to disappear but they were just teasing me! I slept and shivered some more. I finally found my emergency coat – a tattered old garment I keep in the car which my wife would never willingly let me be seen in public with,  and a towel to use as a blanket on my legs. By 3:56 AM the Polarie had tracked Orion high into the sky so little of the foreground was left in the shot. But now the sky was dramatically clearer! Thick clouds threatened in the west but my view of the sky was much better.

I moved the camera and reoriented it vertically so I could keep the slope of the hillside in the shot for at least a while. I watched for a bit hearing the familiar sounds of the shutter closing, pausing, opening…  A brilliant meteor appeared – it was definitely in my field of view! I was almost ecstatic until I noticed the sound of the shutter opening again and realized the bright one had appeared and left while the camera was between shots. It got away! I later discovered that I did catch one little meteor in the vertical mode (see above).

From 4:16 to 4:55 I let the rig continue running in the vertical alignment and retreated again to my car for warmth. But now Orion was heading farther and farther south where the fierce light pollution from Fremont and San José was daunting. I aborted the vertical shot and framed up a lovely spreading oak tree that caught my eye. I spent a solid 15 minutes on that oak tree with Orion hanging above it.

It was now 5:03 in the morning and I was colder than ever.  So I decided I’d reframe the sky shot to avoid the glow of the cities and retreat to the car out of the wind. It was then that I finally really slept and I woke when my alarm went off: 6:02 AM.  I was leading a group of hikers to scrub graffiti off the summit of Mission Peak and some were going to meet for breakfast at 6:30 AM.  The sky was mostly cloudy again, but I spent a few more minutes framing up my friend the oak, collected my equipment and headed for Denny’s.  I spent the rest of the morning and afternoon with a wire brush and paint remover.

After my graffiti scrubbing expedition I was exhausted and slept until early Saturday evening. I copied and started looking through my images. I found a very peculiar one almost right away.  I wondered what the “squiggle” was.

Looking at the frame before the squiggle was still there, though the shape was different.  I kept going backward until I found a brilliant flash. BINGO! It seems the meteor appeared at almost exactly the time that my alarm went off. I never saw it with my tired eyes.

I hastily grabbed the frames from just before the meteor until the floating squiggle ceased to be visible and assembled them into a timelapse:

And there you have it. Almost 5 hours of clouds, a very few meteors and one of the most fascinating phenomenon I’ve ever captured.

By the way, I now have literally thousands of shots to sort through from the following night which was much clearer. So far no brilliant streaks. 🙁

If you’re wondering what settings and tricks to use to capture a meteor, please see my article.

Why your Streak is (probably) NOT a Meteor

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Satellite or Meteor? [C_061879] So you took our advice or perhaps the advice of someone more clever than us and have captured a streaking bit of flaming cosmic stuff that some people call shooting stars. We do not want to rain on your parade, but let’s first get something straight: that flaming streak is more properly called a METEOR.  If it hit the ground, it’s a meteorITE.  If it in fact struck YOU, well you’re a lucky one!  No one in recorded history has ever been directly struck by a meteor EVER. We know what you’re thinking (really, we do). You’re thinking, but dudes: “What about the German boy who was hit in the hand, or the lady who had one bounce off her furniture and hit her in the leg or the man who suffered a broken finger when one crashed through his windshield and bounced off his steering wheel.” Sorry those were METEORITES apparently you weren’t paying attention when we explained the difference between meteors and meteorites.  Did anyone ever find a meteor on the ground? NO THEY DIDN’T… they found a meteorITE. Are we harping? Sorry.

Here is the sad news. You probably DID NOT catch a meteor (or meteorite) in your photo. Terribly sorry to tell you that. Go ahead, bring the photo and plop it in front of us. Claim what you want… but we are skeptics. Below are some things to rule out before we will conclude you have indeed caught a meteor.

Why Are We Such “Meteor Haters”

Hey, don’t put words in our mouth. We LOVE meteors. We just don’t believe you caught one. And here is why.

  1. Meteors move VERY, VERY fast across the sky and therefore across your image.
  2. Only exceptionally bright meteors throw out enough light in their rapid transit to even  register on your sensor or film.
  3. Just because you SAW a meteor occur in the direction your camera was pointing when  it was taking a picture doesn’t mean it registered.
  4. And it probably wasn’t a meteor.
  5. Besides, we think you’re wrong. So there.

Ok, so we admit to being a bit sour about it. After all, collectively we have shot about 20,000 (TWENTY THOUSAND) frames trying to catch meteors. And how many did we get? About 100.  We didn’t get so few just because we suck at it.

Below the Belt [5_020853] CARMAic Visitor from Cygnus [5_034154]
Dew Drop In [C_019416] Chiplet [C_034134]

Perseus slays Little Bear, oh my! [B_032691]

Of those 100, about 20 are readily noticeable. Of those 20, perhaps 10 are well captured. And of those 10, sigh, only a few really stand out.   But perhaps we should admit that we – like you – didn’t make all of those attempts under the best conditions. No, Like you, we took most of our shots when there was moonlight, light pollution, streetlights, and other impediments and the result was as you see at the left here: the meteor is almost impossible to see.  Like you we’ve SEEN a lot of meteors. And like you, most of the time the meteor we saw was regrettably not where we had pointed our cameras.  It’s a game of (very low) odds, after all.

Why You Didn’t Catch a Meteor (or maybe you DID!)

So many times we have seen people post their “brilliant meteor shot”. Almost exactly as many times we noticed one or more of the following:

  1. There are tell-tale flashing white, green or red lights. The tale those lights are telling is “aircraft” but the gleeful meteor hunters have their fingers in their ears.  Look closely at your shot to see.
  2. The streak bends or changes direction and the curvature is not due to field warp (as with e.g. a fish-eye lens). Sorry, but only airplanes curve like that.
  3. The shot immediately before or the shot immediately after the prize has the continuation of the streak. There is a 0.000008% chance of capturing a single meteor that spans more than one frame.
  4. The shot was at low ISO (less than 400), a high f/stop (anything above f/4), a narrow field of view or for a very long time. For a meteor to register you’d need a super slow flaming fireball of a meteor. If in fact you got one, well good for you and we are jealous.
  5. After ruling out aircraft, most people fail to rule out the next most obvious possibilities: satellites, flare and moths.   Yep, moths or any other bug that might fly through a source of illumination. We’re pretty sure you’ll be able to tell if it was a firefly though. Satellites are a little sneakier. They can – and do appear, move through the sky and disappear.  And they can fade in and out, too.

Satellites

There are MANY satellites in the sky. So many that we catch them ALL the time.  About every shot that doesn’t have a stinkin’ airplane seems to have a bloomin’ satellite in it.  Most satellites are quite dim and you don’t see them easily with the naked eye, however there are a few bright ones and one family of satellites that is EXTREMELY bright for a brief time.  We’ll get to that in a minute.

Meteors and Meteorites Have A Signature

Star Man and Perseus [C_059960-1]

Perseid Meteor, Milky Way and Galen’s Arch, Alabama Hills, Lone Pine, California, August, 2012

Most meteor streaks have the following things in common:

  • They brighten rapidly and dim a bit more slowly.
  • They are asymmetric (the brightening phase and dimming phase rarely look exactly alike)
  • Because of the two things above, meteors streaks rarely, VERY rarely have nice round ends – generally one or both ends are tapered.
  • Often meteors are colored!  The Perseids, for example, are often green, the Orionids are often yellow.

Perseid meteor traveling from the lower left to upper right. Note the changes in brightness and color

About those Bright Satellites

Satellites seem to wink in and wink out because they are illuminated by sunlight.  You’ll rarely see a satellite at the (true) midnight hour because the earth prevents sunlight from striking the satellite. However for as much as 3 to 5 hours after sunset or before sunrise (and more at other elevations), a satellite may move quickly and stealthily out of the earth’s shadow into a place where it can be seen clearly against the dark sky.  Or it might do the opposite: streak across the sky and then wink out when it enters the earth’s shadow. But there is one spectacularly bright satellite. Sorry did we say one, we meant 90 of them!  The family of satellites named Iridium. The name Iridium refers to the planned 77 communication satellites – the atomic number for Iridium is, 77.  The Iridium satellites exist to service those big, bulky sat phones – about the only option you’ve got if you need phone service in the Bering Sea or on an ice shelf in Antarctica.

Satellite Flash (Iridium) [5_033852-4br]

Iridium and “Flares”

Because the Iridium satellites are highly polished, and because each of those 90 objects are circling the earth every 100 minutes or so at a relatively low orbit, it’s not at all unlikely that one will reflect the light of the sun toward you! If you happen to be in just the right spot the brightness is extreme.  How extreme? Astronomers use a stellar magnitude scale. On this scale the smaller the number, the brighter. The stars in the Big Dipper are around 3, the brightest star, Sirius, is -1.46; Venus, the brightest planet at its shiniest is -4.6 and the brightest Iridium flares are -9!  What this means is: Iridium flares can be more than 20 times brighter than Venus or about 400 times brighter than the brightest stars!

Iridium satellites move swiftly but nowhere near as fast as meteors so they are far more likely to leave a mark in your photo than a meteor. Iridium flares behave very predictably. They start dim, slowly grow brighter and then slowly fade all the while that they transit the sky. If you want to mess with someone, use an Iridium sighting tool, figure out when and where to look in the sky and tell people nearby: “I have this sense… that something strange is about to happen… right … up … there”.  If you time it well people will be so amazed they may fall down and worship you. Time it wrong and they will laugh. Either way it’s great fun.  [NOTE: That link will only work in MILPITAS, CA – you need to use your GPS location].

The thing is, however that your camera doesn’t know when the grand entrance is going to happen and it will dutifully record the event while you’re busy chatting with your fellow night denizens.

Meteor Radiant Point (Delta Aquarid Meteor Shower)
Unfortunately we ran out of space before we got a chance to explain to you that even your correctly identified meteor is probably incorrectly identified as a “Perseid Meteor”.

In summary, we TOLD YOU you didn’t catch a meteor!

But if you think you did and are willing to stand some public humiliation at being proved wrong, please post ONE alleged meteor shot below in the comments.  Please also give us the date, time, timezone and GPS location so we can make sure it wasn’t an Iridium Flare. Wait, why make us do that… do it yourself! The exposure information is important, too (length, f/stop, ISO, focal length).

Oh, one last thing… did you find this article interesting? Amusing? Alienating as hell?  Please share it!

Coaxing a Meteor into Smiling for your Camera

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Nothing is quite as exhilarating – to me at least – as watching the sky explode with “falling stars” or meteors as they are more properly called. Major meteor showers occur through out the year but the most spectacular and reliable showers are the Perseids in August, the Lyrids in April, and the Geminids in December. Other notable showers include the unpredictable Leonids in November. In fact, in November there are quite a few minor meteor showers including the Northern and Southern Taurids, and the Aquarids.

An absolutely brilliant example of well captured meteors can be found in Gary Randall‘s work.

Perseid Meteor Shower over Mount Hood

Photo 1: by Gary Randall. Gary captured 26 meteors over a 3 hour period and realigned them to show their path through the starry sky. 30 second captures f/2.8 ISO 1600 at 11mm on a Nikon D90.

Capturing meteors is much harder than it may seem, however and getting results Like Gary’s is far from a “done deal”. Let’s investigate why and figure out how to successfully capture them.

If you’ve been reading this column for a while you’ve probably already successfully captured a star filled sky. Your camera settings were likely something like this:

ISO 200, f/4, 30 seconds, Focal length 24mm.

There are two components to meteors that make them difficult to capture.

  1. Meteors do not appear in a predictable location in the sky. Indeed all meteors from a particular shower appear to radiate from a single point in the sky, but the meteors streaks may appear anywhere.
  2. Meteors are fast. Very fast. And even though they may be bright their speed makes them more difficult to capture because their light does not linger over pixels in the sensor like stars or stationary objects do.

Since meteors may appear anywhere in the sky a common strategy is to use the widest possible lens you can and “fire the shotgun” at the sky. This strategy can work however use of a wider angle lens means the sensor area that will be struck by the light from a meteor is diminished.

Most important, however is the effective exposure. A short exposure with a wide open aperture at the highest acceptable ISO setting will catch the most meteors against a still sky. In other words ISO 2000, f/1.8, 20-30 seconds at 50mm focal length will capture a streak more effectively.  If you can stomach it, ISO 6400 will capture even more – and it may not matter that the image is noisy because you may end up using only the “streak” not the whole frame. It may seem tempting to just expose for say 10 minutes but unless the sky is very dark, that strategy will not work well.  Skyglow will overwhelm the area through which the meteor passes and thus reduce the contrast.

The second problem is where to point the camera.  If you use a wide angle lens or a fisheye lens you can point it almost anywhere you like. But it is helpful to know where the radiant point is. I like to be sure that the radiant point is in the picture. There is a downside to shooting near the radiant point: the closer the meteor is to the radiant point, the more “straight on” the meteor will be and the shorter the trail will be.  However pointing the camera somewhere away from the radiant point means your chances of catching a meteor go down exponentially – but what you do capture may have a longer streak.

It took me nearly 1200 attempts to get this one meteor in my back yard in San Jose, California. The camera was a Canon 50D at f/5.6 and ISO 1600. It is much noticeably grainier than a more recent capture on my 5D Mk II from Maui.

Below the Belt [5_020853]

Photo 2: One in 1600 shots that caught (almost all) of a meteor glancing through Orion’s belt. Settings: f/5.6, ISO 1600, 30 seconds, 23mm.

Half of a Brilliant Perseid [C_006711]

Canon 5D Mk II at ISO 2000, f/2.8

Here is an interesting thing to note: the radiant point of the Perseid Meteor is not far from the north celestial pole – that is, where Polaris the north star is. The radiant point of Leo, however is near the celestial equator. Why would that matter? It matters because in 3 hours the Leonid radiant point will have moved a fourth of the way across the sky while the Perseid radiant point will be probably still be in your frame.  In fact, David Kingham has written an excellent article about how to point your camera specifically for the Perseid Meteor Shower.

Back to Gary’s work for a moment. The meteors did not all come at once… no sir. The earth was busy rotating and the meteors shown in the photo were captured over 3 hours time! Had they all occurred at once they might have looked like the Photo 1 above.  Placing each meteor where it fell in the frame shows a different story – still compelling, but a bit more chaotic.

My thanks to Gary Randall for allowing me to show his excellent work. I heartily suggest you purchase a poster of his work to inspire you. I am doing so!

For more information about meteor showers and how to view them, there are many sites on the internet.  EarthSky.org is a great resource, for example.