This was the first night of our October workshop last week. The weather forecast was for heavy rain in the evening and we had been treated to better-than-forecast weather on the South coast earlier that day. We had dinner at Hali Country Hotel and couldn’t believe it when we stepped outside expecting rain and found clear skies with active Northern Lights. We decided to head out to a local spot away from any hotel lights.
We set up our cameras at the edge of the pond, our starting exposure was 20 seconds at iso 800 and f/2.8, but for this shot, I boosted the iso to 1000. I used a magic cloth to cover the sky after about 15 seconds and gave the reflection the full 20 seconds. This was a very subtle effect, but I didn’t want the reflected lights to burn out. The reason for trying to expose the night sky for less than 20 seconds was to avoid star trails. To calculate an exposure to avoid star trails, we use the 600 rule (actually 500 is easier for mental arithmetic). Divide 600 by your focal length (how wide your lens is in mm). For example 600 / 24mm = 25. This mean that stars will noticeably trail if the exposure is over 25 seconds. If I was shooting with a 17mm focal length, the stars would noticeably trail in exposure over 35 seconds. This northern lights photograph was taken with my 24mm prime.