Share your Astrophotography Photos

[lindam]

Are you a fan of astrophotography? Post your favorite photo you've taken and share the story behind it. Be sure to include the Canon gear you used.

[Waddizzle]

"You can see where the center of rotation is, and you know that a full rotation takes 24 hours."

Not really.  Several short exposures of, say 6 or 8, of approx. 5 to 10 minutes can do that.  It also eliminates a lot of error factors from long exposures.

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I was confused.  Were you saying the total exposure time was 5-10 minutes, or each exposure was 5-10 minutes?  I think the total exposure time is 2-3  hours.

[ebiggs1]

"I think the total exposure time is 2-3  hours."

Possibly. I wouldn't argue.  Who knows for sure?  It just doesn't require 24 hours.

[TheCanon]

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@ebiggs1 wrote:

"I think the total exposure time is 2-3  hours."

Possibly. I wouldn't argue.  Who knows for sure?  It just doesn't require 24 hours.

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So multiple 5-10 minute long exposure shots for a total of 2-3 hours or one big 2-3 hour exposed shot? You guys are confusing me lol.

[Waddizzle]

"So multiple 5-10 minute long exposure shots for a total of 2-3 hours or one big 2-3 hour exposed shot? You guys are confusing me lol." 

You just hit the nail on the head.  There is no one answer, "Do it like so." Captuing an image of star trails like that is not a task for the beginner.  It requires a lot finesse, creativity, and experience at shooting in the dark and the night skies.  I would not take exposures as long as 5-10 minutes, for the exact reasons that Ernie has already cited.  Noise.

You will learn that using the same exposure time with widely different focal lengths can give widely different results, most especially when it comes to star trails.  The focal length and aperture that you use will directly impact the best exposure time to capture star trails.  There is a lot room for variance in the Exposure Triangle. 

I would also advise starting out small and working your way up: like taking shots of the Moon on full, half, and quarter phases, to learn about how to take pictures of the night skies.  Taking shots of the Moon will teach about stabilizing your camera on a tripod, releasing the shutter, and optionally shutter lockup. I would suggest taking pictures of the Moon just as the sun sets, or rises, too.

I would think the next step would be taking a wide field shot of night landscapes and the night sky, where you would learn about stacking photos, white balance, and exposures, or even layering if you use a commecial applicaiton like Photoshop Elements, or Photoshop CC.  Taking shots landscapes with full Moon at your back can produce some pretty dramatic looking shots.  I would use the same White Balance as I would for a bright sunny day., because the Moon is a perfectly neutral reflector of direct sunlight. 

Once you have gone through those trials and errors, you could attempt to create a final shot of star trails.  I would encourage taking shots of star trails all long the way, too. 

[TheCanon]

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@Waddizzle wrote:

"So multiple 5-10 minute long exposure shots for a total of 2-3 hours or one big 2-3 hour exposed shot? You guys are confusing me lol." 

You just hit the nail on the head.  There is no one answer, "Do it like so." Captuing an image of star trails like that is not a task for the beginner.  It requires a lot finesse, creativity, and experience at shooting in the dark and the night skies.  I would not take exposures as long as 5-10 minutes, for the exact reasons that Ernie has already cited.  Noise.

You will learn that using the same exposure time with widely different focal lengths can give widely different results, most especially when it comes to star trails.  The focal length and aperture that you use will directly impact the best exposure time to capture star trails.  There is a lot room for variance in the Exposure Triangle. 

I would also advise starting out small and working your way up: like taking shots of the Moon on full, half, and quarter phases, to learn about how to take pictures of the night skies.  Taking shots of the Moon will teach about stabilizing your camera on a tripod, releasing the shutter, and optionally shutter lockup. I would suggest taking pictures of the Moon just as the sun sets, or rises, too.

I would think the next step would be taking a wide field shot of night landscapes and the night sky, where you would learn about stacking photos, white balance, and exposures, or even layering if you use a commecial applicaiton like Photoshop Elements, or Photoshop CC.  Taking shots landscapes with full Moon at your back can produce some pretty dramatic looking shots.  I would use the same White Balance as I would for a bright sunny day., because the Moon is a perfectly neutral reflector of direct sunlight. 

Once you have gone through those trials and errors, you could attempt to create a final shot of star trails.  I would encourage taking shots of star trails all long the way, too. 

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Wow thank you for this. I thought it was an easy task with a bit of thought process behind it. Thanks for saving me the disappointment! I'm just an ambitious newb 

[Waddizzle]

"Wow thank you for this. I thought it was an easy task with a bit of thought process behind it. Thanks for saving me the disappointment! I'm just an ambitious newb "

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It is easy.  It just isn't as simple as it might seem.  BTW, did I forget to mention to take the shots in manual mode and manual focus?

[TheCanon]

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@Waddizzle wrote:

"Wow thank you for this. I thought it was an easy task with a bit of thought process behind it. Thanks for saving me the disappointment! I'm just an ambitious newb "

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It is easy.  It just isn't as simple as it might seem.  BTW, did I forget to mention to take the shots in manual mode and manual focus?

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You did not mention that but I've watched several YouTube videos that suggest the same. I just got my wireless remote shutter so I think I have all the gear I need to shoot some awesome pics! Just waiting for a clear night and my buddy to clear his weekend schedule so I don't have to do this alone 🙂

[ebiggs1]

Desert in Arizona.  EOS 1D Mk IV with ef 70-200mm f2.8L IS USM II @ 95mm.

[ebiggs1]

You can see the brighter streaks of the stars is not too long. Could be an hour. The camera is pointed towards Polaris.

A good starting setting of ISO 400 at f/2.8 or f/4 might work.  Depending on how much light pollution, or dark skies, you have at your place, an exposure as short as 30 seconds might work. At darker sites, you might be able to expose much longer.  Exposures that are too long will deteriorate quickly because of noise and heat. Plus some other factors like atmosphere distortion.

Might be two shots, too!  

[Waddizzle]

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@TheCanon wrote:

How long of an exposure would this type of shot be?

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Comparing the length of outer arcs to how much time an hour hand on an analog clock would take to travel that far, I would say it looks to be roughly about an hour.  However, most clocks are 12 hour displays and the Earth takes a full 24 hours to do a full rotation. 

In other words, what ever your estimate is for how much travel by an hour hand is....double it.  I'd venture that the shot is somewhere around a 2-3 hour sequence of stacked exposures.  How many is anyone's guess.  I would not be surprised if the total was closer to 100 shots than 10 shots.

Others things to note are the angle of view and the angle to the apparent horizon of the center of axis of rotation, either the North Star or the South Star.  The angle of view isn't very wide, but it isn't very narrow either.  I'd venture to guess that a focal length between 50mm and 200mm was used. 

Furthermore, the polar stars are not as close to the horizon as the shot might seem to suggest.  I'd venture that it was taken at the bottom of a hill, looking up towards a ridgeline of trees at the top of the hill.  There are numerous free applications to help you find the North and South stars once you know your current GPS position, date, and time of day.