Tag: Long Exposure

On Thursday night I went out with my son to photograph Comet NEOWISE. This is a comet that was only discovered a few months ago on March 27 by NASA’s NEOWISE telescope.

Comet nuclei are cosmic snowballs of frozen gases, rock and dust that orbit the sun. They can range in size from a few miles to tens of miles wide, and the nucleus of NEOWISE measures about 3 miles across. When these comets approach the sun, their frozen bodies start to sublimate, and they spew dust and gasses in a tail that can span millions of miles.

Comet NEOWISE made its harrowing close approach to the sun, known as its perihelion, on July 3, and it is now zooming past the Earth on its way back out of the solar system. NEOWISE will make its closest approach (64 million miles) to Earth on July 22, but the best viewing window is happening right now until July 19.

There were a few clouds in the sky, but with the sun setting very late we went out around eleven thirty.

We didn’t have far to go, heading to a local field looking north where I knew the comet would be. The Stellarium mobile app helped me figure out where to look as it’s more north-west than simply north. Look towards where the sun is setting, or has set, and you’ll find it.

At first I took a wide angle photo of the sky as I couldn’t see the comet at all. Once my eyes grew accustomed to the dark I could just about see the comet if I didn’t look directly at it. I can imagine in darker skies it probably would have looked even brighter!

I took a few more photos of this scene but as the night sky got darker I realised I needed a point of interest to draw the eye in. The electricity pole in the field served that purpose well.

As the minutes ticked by I was reminded that focusing in the dark is extremely hard. I recalled that someone mentioned pre-focusing at infinity in daylight hours and marking the place on the lens. I remembered outings with my photography club where someone would shine a light on themselves to help focus. If I had a flashlight I would have gladly used it to focus on that pole. I have so many out of focus photos of that pole and the comet!

It was midnight and I promised my son I’d take “just a few more photos” before we headed off. I had no idea now if the pole was in focus. Zooming the lens adjusted the focus so I had to refocus. We tried shining the lights from our phones on the pole but it barely made a difference. The grass was long and wet with dew so I didn’t want either of us to go trudging through it to shine a light on it. I think I got reasonably lucky with the last shot!

The comet will be back in 6,800 years. I wonder if any of these photos will survive until then?

I’m glad you got to the end of the post. Here’s my top tips for capturing the meteor or just for taking photos of the sky at night:

1. Open up the aperture as wide as possible. My zoom lens only went to f/6.3 🙁
2. Bump up the ISO as the light fails to keep the exposure time short. You’ll capture stars too which is a nice bonus. I went to ISO 4000.
3. A longer exposure records the motion of the Earth. The comet will start to streak and get bigger which you don’t want. I found < 10 seconds, or around 6 seconds best.
4. Make sure you have some foreground interest. Bring a flashlight to shine on that object to help focus when it’s impossible to manual focus as it’s too dark. Bring someone along to shine a light on the scene to help focus.
5. I forgot this on the night, but bump the ISO to it’s max to help you focus manually on your foreground interest. Reduce the ISO to shoot.
6. During daylight hours manually focus on something at infinity. Mark on the lens where that is. It’ll make it simple to focus there when it’s too dark to focus. Similarly, if you know where you’re shooting, focus where your subject will be on the night, and mark the focus.
7. You don’t need a 300mm or 400mm telephoto lens to shoot the comet. The most interesting photos of it are wide(ish) angle. I should have tried shooting with my nifty 50.