The Night Before Easter
Easter Sky Over Sturgeon Lake | C25-0007
After doing some night sky photography during our recent trip to Joshua Tree National Park, I was eager to do more of it when we got back home to Minnesota. A perfect opportunity presented itself during a stay on the northern shores of Sturgeon Lake over the Easter weekend.
Nerdy information alert — the following paragraphs explain the technical trivia that produced the star trails image above.
It started out with the planning of the star trails image with an app call PhotoPills — when to start, number of images to take for stacking, exposure, etc. Then some pre-visualization onsite before taking a couple of early twilight images to blend with the final star trails stacked image. I programmed my intervalometer for 180 exposures, each for 20 seconds with an interval of five seconds between. With a bit of trepidation, I hit the start button on the intervalometer at 9:19pm. I had tried this same plan just a few weeks earlier, but it ended in failure when the camera battery died before all the exposures were taken — poor planning on my part. This time, however, I started with a freshly charged battery and 75 minutes later the exposures were completed at 10:35pm. Final image count was 183 exposures.
Once I had the 183 images imported onto my computer, I did some basic tweaking, then exported the tweaked images and loaded them into an app call StarStax to stack them all together into a single image to produce the illusion of star trails (note that the illusion of movement is due to the earth’s rotation). The star trails show how much rotation occurred during the 75 minutes which elapsed during the taking of the 183 exposures.
Remember earlier, before starting the intervalometer, I had taken a few twilight shots of the sunset fading below the horizon. I selected the best of these shots and made a few tweaks — this shot would be used to blend with the stacked start trails image since the 20 second exposure for the stars resulted in “blown out” lights along the horizon.
The stacked star trails image was loaded into Photoshop along with the foreground image taken just after the sun dipped below the horizon. The “select sky” function in Photoshop made quick work of blending of the star trails image with the foreground of the sunset image.
Once work on the star trails image was complete, I decided to see what just one of the exposures used for stacking would look like when blended with the same foreground image. This gave me the image below, with the sky and stars from the first image in the sequence.
The Easter Vigil | C25-0008
The stars in Orion’s belt are clearly visible on the right side of the frame. And Sirius, the Dog Star, is shining brightly in the center straight to the left of Orion.