Night sky photography by Chris Kotsiopoulos 6

Hello there. My name is Chris and my idea of having fun is to be out in the cold, in the middle of the night taking photos of the stars! The Moon, the planets, the constellations and the Milky Way are not only favorite photographic targets but also source of pure inspiration!

Chris Kotsiopoulos

Chris Kotsiopoulos

The beauty and the magic of the night sky is taken to a new level when properly combined with a beautiful landscape.

In the past few years I was fortunate enough to capture some photos that have something to say. After all, this is the important part. The photographers are story tellers and the story of the twinkling stars is perhaps the most exciting!

The first photo tells us the story of a new astrophotographer trying to catch Earth’s celestial companion aligned with one of the most important monuments of the ancient world, the temple of Poseidon. My equipment was humble, a cheap 70 euro telescope coupled with a mid range DSLR tied with a rope(!) to a small tripod. Today, my equipment is better but this photo remains my favorite.



Night Sky Photography. Moon and the temple of Poseidon.

Night Sky Photography. Moon and the temple of Poseidon.

The second photo is a story of a cataclysmic storm that took place a few hours during the total lunar eclipse at June 15 2011. Lightning,  stars and the eclipsed Moon in one nearly unbelievable shot.

Lunar eclipse and lightning

Lunar eclipse and lightning

The third photo is a story of one day! 24 hours, 500 startrail shots, 35 captures of the Sun and 25 landscape shots in one image!

Night Sky Photography. 24 hour little planet panorama.

Night Sky Photography. 24 hour little planet panorama.

In a series of tutorials I will try to cover all the aspects of night sky photography. Let’s start with some basic tips, tricks and guidelines.

  1   Find the place. Typically you will be shooting in nice sceneries away from the city lights that cover the most of the star light (if not all!).

  2   Use a sturdy tripod. Night sky photography requires long exposures. Especially if you want to shoot startrails, the camera must be completely still for hours.

    Use a DSLR and a wide field lens. DSLRs perform better than point and shoot cameras and they give you much more flexibility. I use a crop 1,6 camera (canon 550D) and most of the time I take photos with a 15mm fisheye lens. Have in mind that at night sky photography most of the action takes place at the sky, therefore you should have a wide field of view to include the foreground and a large part of the sky.

  4   Prime lenses in my opinion are better. They don’t have the flexibility of a zoom lens but they are generally sharper and faster than zoom lenses. You need a fast lens to capture these nice constellations and the Milky Way.

Milky Way at Ikaria island.

Milky Way at Ikaria island.

  5   Focus the camera on a distant light, or the Moon and then lock the focus indicator to ‘Manual focus’. If there is no Moon or distant lights you could try to focus on a bright star. This may be tricky. If your camera has a live view, use it. It really helps. If it doesn’t, set the focus manually close to infinity (strangely at DSLR cameras stars do not focus perfectly at infinity…) and then do some try and error attempts adjusting the focus and inspecting the photo until the stars are sharp dots.

  6   Adjust the camera settings. One word here. MANUAL! Set everything manually. The typical settings I use are the following:
• Exposure: 20 – 40 seconds. Anything more than 40 seconds introduces star trailing because of the Earth’s rotation. This is fine if you want to shoot startrails but if you intent to take a photo that show relatively round stars you are limited to 30 seconds or even less depending on your focal length. Some indications:

50 mm Lens

Star Declination Exposure
0 degrees (on the celestial equator) 8.5 seconds
30 degrees (60 degrees from the celestial pole) 12.5 seconds
60 degrees (30 degrees from the celestial pole) 25 seconds

24 mm Lens

Star Declination Exposure
0 degrees (on the celestial equator) 17 seconds
30 degrees (60 degrees from the celestial pole) 25 seconds
60 degrees (30 degrees from the celestial pole) 50 seconds

• ISO 800 or 1600 is a reasonable choice. High ISO introduces digital noise. If you have a low noise full frame DSLR camera you could try even more. With my Canon 550D which is a mid range DSLR most of the time I use ISO 1600. In a light polluted area or in a moonlit scene you will probably use a lower ISO like 200 or 400.
• Aperture. Set it wide open to capture as much photons as you can in the short period of time before trailing start to show. You may want to close it at one stop to get sharper results. So if you have an f/2.8 lens, one stop closed is at f/4.
• White balance. I use Daylight. It doesn’t really mattter if you shoot in RAW format.

  7   Use an intervalometer or a cable shutter release. The intervalometer is a better option as it allows you to program continuous shots.

  8   SHOOT IN RAW FORMAT! This will give you great flexibility at post processing.

  9   Charge the batteries. If you plan to shoot startrails have in mind that your camera should operate continuously for hours. In order to create a startrail photo you have to stack a series of images. Also during startrails shooting the camera must remain completely still. If you move the camera even slightly to review a photo or to change a battery your photos will be misaligned and the final result blurry and inaccurate. Using a battery grip that holds two batteries doubles your exposure time. If you want to go further and shoot for hours consider an AC Power Adapter or a big external 12V battery coupled with an adapter cable.

 10  Get 2-3 high capacity memory cards. A series of images especially at RAW format can fill your card fast.

 11   Dew is one of the challenges of night sky photography. Lens hoods or even dew heaters help a lot.

 12  Enjoy shooting!

6 thoughts on “Night sky photography by Chris Kotsiopoulos

  1. Reply Jen Apr 3, 2013 10:55 pm

    Thanks for the tips! Great photos. I noticed you say you usually shoot with a 15mm but didn’t leave any more detail on your other settings using that. Why the fisheye? I am new to astrophotography and getting some OK results, but want to go further.

  2. Reply Chris Apr 12, 2013 7:40 am

    Hi Jen. Thanks for your kind words! You are right about the fisheye. It is the lens I use most frequently. This has to do with my personal shooting style and with the fact that in night photography you have to consider the fact that your main subject is the sky, so if you want to include both the landscape and plenty of sky, then you need wide field lens. Furthermore with a wide field lens you can go up to 30-40 seconds exposures without having the trailing issues with the stars (stars appear like ovals due to the Earth’s rotation.) Finally, this particular lens gives very good, sharp results.
    About the shooting settings, I usually give these:
    Canon EOS 550D
    Shooting Date/Time 30/8/2012 3:20 – aprox. 5:30
    Tv( Shutter Speed ) 20 x aprox 400 shots
    Av( Aperture Value ) 4.0
    ISO Speed 400
    Lens EF15mm f/2.8 Fisheye
    Focal Length 15.0 mm

    There is an amount of image info available, like the following which I exclude because I consider it as clutter:

    Owner’s Name
    Image Size 5184×3456
    File Size 3406 KB
    Dust Delete Data No
    Drive Mode Single shooting
    Live View Shooting OFF
    Etc…etc…

    I you think that it would be helpful to include something more, I’m open to suggestions.

    Take care.
    Chris.

  3. Reply Tim Jun 14, 2013 1:28 am

    Chris, great photos. I am a budding amateur with similar appreciation for wide field astrophotography. I have some questions.

    Can you comment on the settings you used to get such detail in the Milky Way. I know it helps to start with a dark sky, and I suppose you are possibly stacking images, but what are you specific camera settings for that shot? Where I live, Washington,DC, if I travel 3 hours to a dark site I can barely make out the galaxy naked eye and can’t pick it up in a photo.

    What software do you use for stacking?

    The “24 hour little planet panorama” shot is amazing. How did you shoot that and how did you put it all together?

    Thanks for your time.

    Tim

    • Reply Chris Jun 20, 2013 12:05 pm

      Hello Tim.
      Thanks for your kind words! I think you refer to this image:
      http://www.greeksky.gr/greeksky/slides/Selections/album/slides/20100613MilkyWayChris.htm

      Stacking is a good thing as it improves the signal to noise ratio. The problem is that you only have 30 – 40 seconds before the star trails start to show in your photo. (the 30 – 40 seconds is barely a rule… It is just an indication that works in my setup (A crop 1.6 DSLR camera with a 15mm lens). In these 30 – 40 seconds I only have time for one shot.
      So, for the Milky Way I don’t stack. I stack in startrail photos with Startrails.de software. I also stack when I do deep sky astrophotography (camera on an equatorial mount that ‘follows’ the stars. Usually at this kind of photography we only shoot the celestial objects without an earthy foreground as it will blur from the mount’s motion). For the Milky Way, I try to catch the most light I can as fast as I can. So, the settings for the above photo are:
      - ISO 3200
      - Shutter Speed 30 sec
      - Aperture Value 2.8
      - Focal Length 15.0 mm

      As you said, you need a really dark sky. With the above settings even the slightest light pollution will show in your photo. To bring out the detail you need to stretch the image at post processing. I use photoshop for that. Experiment with Curves, brightness/contrast, shadows/highlights. I also use Iris’s sblur command to emphasize the brightest stars.

      About the 24 hour photo, the basic info is here:
      http://www.greeksky.gr/greeksky/slides/Selections/album/slides/20101230Sounio24.htm

      …and a detailed tutorial here:
      http://www.greeksky.gr/greeksky/slides/Tips/album/slides/20101230Sounio24Tutorial.htm

      Regards,
      Chris.

  4. Reply Constantinos Aug 29, 2013 8:08 am

    Dear Chris,

    excellent site and great info on astrophotography which is also something I am getting into. I have the following questions and would appreciate your help.

    1) I have seen in one of your startrails shots that there is a little star effect at the end of the startail which I presume, the last shot was taken using a much smaller aperture. Could you please explain how this is achieved?

    2) I am trying to stack images of the milky way using Deep sky stacker (I do not mount the camera to track the earth´s movement) but all my attempts are unsuccessful. How do you stack an image of the MW? What sort of software you use?

    Thanks in advance and regards,
    Κωνσταντίνος

    • Reply Chris Oct 31, 2013 9:17 am

      Γειά σου Κωνσταντίνε.
      1) About the star effect. The last shot is taken with exact the same settings with the others. It is the result of post processing. I create a new layer in photoshop with the last photo of the star trail sequence and I blow up the stars. The technique is known as Akira Fujii effect. Then I add spikes to the stars. You can do it with photoshop manually or easily with a plugin. Finally I add the layer on the star trail sequence with an opacity around 50%.

      2) The software I use is a freeware called Startrails.de. It is very easy to use and the last version even fills the gaps between the shots!

      Best regards.
      Chris.
      http://www.greeksky.gr

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