There are a few requirements for photographing the sky during night. For the best results, there must be as little light pollution from the surroundings as possible. I also need
- a tripod (check)
- a wide angle lense with aperture of f2.8 (i have a 14-24 1.8)
- Camera (I have a mirrorless full frame Nikon camera)
- Remote/release cable with bulb mode (check)
It can also be smart to have a torch/head lamps – to find a good location in the dark, and warm clothes.
This is how to set-up an astro photograph
- widest aperture available
- Long shutterspeed. However, if the shutter speed is too long, there will be star streaks in your image due to the earth’s rotation. Here you can use the 500 rule: Divide the number 500 on the chosen focal length. For example, if I shoot at 12 mm, the calculation is 500/12 = 41. The exposure time can be 41 seconds before the earth’s rotation has an impact on your image. This is valid on a full frame camera.
If you want star streaks, you must have significantly longer exposure time, at least 10 mins up to one hour. However, the noise will be quite notisable on the image and the sensor might get overheated. You can solve this by taking multiple images with “too long” exposure and stack them in Photoshop.
How to focus in very dark environments
- A head-light can help you to set focus. 2) If you focus in advance, you need to lock the focus ring using gaffa or some other kind of tape. 3) Use live view to focus.
How to photograph Aurora (Nordlys)
The northen light can be challenging to photograph, as the light changes by the instance and you have to do ajustments. The settings may vary, but this is a good starting point:
As wide apperture as your lense allows (ex f 2.8 or wider)
Shutter 15 sec*
ISO 1600
* If the Aurora is not very active, i.e., it’s not moving a lot, you can increase the shutter speed if your photo is too dark. However, with a very active Aurora, five to eight seconds is probably as slow as you’ll want to go to let enough light in without smearing the dancing lights. Increase the ISO if the shutter speed smears the Aurora effect.