Photo By: Me – Got a new 11-16 lens for the Nikon last night and decided to play.

I created these simple startrails last night just to run the new lens through some paces (Tokina 11-16mm) and this is the result of one of the projects I worked on last night. While I was doing this it got me thinking I should create a post on HOW TO make startrails……so here goes.

EQUIPMENT BASICS = I have a Nikon D90 DSLR so if you have any ambition to do these with film I probably can’t help you. Actually I don’t think I have ever used a manual film camera, just used my grandmother’s point and shoot 110 back in the day.

Anyhow, aside from the obvious battery charge, memory card, tripod (Yes you must or you will get vibrations in your trails), shutter release cable and dress for the weather; you will first want to choose what lens and or focal length you want to shoot at. Keep in mind stars make one round trip in 24 hours due to Earth’s rotation (That should be obvious I suppose) so the wider your lens the longer it will take for trails to begin but in my opinion the better the photo will look. You can zoom into 300 and get startrails done in minutes but you won’t get much of a photo from that small cropping. So go as wide as you can as it affords a much better photo and more options therein.

Also think of stars traveling across the sky like a fan blade, so if you are doing trails using one of the poles (as I did here) it will take longer than if you shot your trails to the east or west because the polar regions stars have a small circle to travel in that 24 hour rotation thus they move more slowly while stars to the east and west have to move much faster across the night sky to make a full rotation and return to “start” in 24 hrs. Shooting to the east or west won’t give you that circular rotation movement to your photos; instead they will sort-of “streak” across the sky. Still very cool though when done right. My southern hemisphere friends don’t have a pole star so you will lack that central stationary star but you will still get that circular motion when shooting to the south. NOTE: whatever your latitude is will be how high in the sky your celestial pole will be. For example my latitude is 43 so Polaris (the North Star) is 43 degrees high.

You will be shooting in FULL MANUAL MODE this means aside from using the camera in manual you will want to make sure the lens is also set to MANUAL and if it has VIBRATION REDUCTION (VR) on the lens set that to OFF as well. To achieve focus set your lens to infinity or just zoom in to a bright star, achieve focus then zoom back out (You will be focused to infinity so zooming back after out will not change your focus). Don’t shoot in live view either, this will also cause a delay in the rapid succession of shots you will need.

Next step is determining your exposure lengths and let me STRONGLY advise you to shoot multiple 30 second shots vs. one hour-long or more exposure that you later discover to be flawed because somehow the camera suffered motion. With shorter exposures you can eliminate individual frames if needed with minimal impact to the final product. You will also want to turn OFF your cameras INTERNAL NOISE REDUCTION so you can take long exposure after long exposure without large gaps between every photo.

Your settings for the night sky will be individual for you; I have a lot of light pollution so at 11mm, I shoot at f2.8 and ISO at 400. That may be different for you, I almost promise that. It’s just a matter of finding a starting point, experiment a little by taking some test shots and when you are happy with a 30 second exposure you’re dialed in to that location. Because of my light pollution issues I also throw the lens cap on and shoot about 20-40 exposures of 30 seconds of black shots called DARKS. When I stack those into the image in processing it helps reduce much of that noise. A trick I like to use is – I shoot at 30 seconds via the cameras timer vs. using bulb mode and timing out every shot. I also use a shutter release cable (which I strongly recommend) and when you combine 30 second, internally timed photos with a release cable you can hit the button, lock it into place and it will take constant 30 second photos indefinitely until you decide to come back and hour or two later to stop it.

Finally what do I always say for wide field night sky photos? Location is everything! The last thing you want is shot of the roof of your boring house like I did (I didn’t care I was just testing the lens). Go scope out some locations, horizons, use something in the foreground, pay with light painting etc. etc…’s limitless.

As far as stacking I use a FREE software called, well……STARTRAILS. It’s free and easy, you just load all of your frames, load all of your DARKS and hit the startrail button and it stacks them all together for you. Then just save the final image, then, if you choose open in Photoshop and process further if you wish.

1 = Battery charge, memory card, tripod, shutter release cable.
2 = Camera and lens you want to use. Use both in manual mode; turn VR on the lens off, turn off internal noise reduction.
3 = Determine how long you want your exposures to be and shoot some test shots to get your settings correct. I recommend 30 second exposures for flexibility.
4 = Fire away! Get at least 30 minutes to an hour of night sky exposures and if you can get half that in DARK exposures. For example if you get 1 hour of night sky, get 20-30 minutes of dark exposures with the lens cap on. Make those dark exposures the same length and in the same environment as well.
5 = Go home, throw them on your computer and stack them all together by whatever means you choose (I use the free STARTRAILS program

If you have questions as always feel free to ask! I don’t think I need to say that to you guys anymore but seriously, ask away that’s how you learn.


Image | This entry was posted in Astronomy (Learning), Astrophotography (Wide Field), Stars (Non-Sun Related) and tagged , , , , , , . Bookmark the permalink.

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