Comparison of dark sky and back garden
The local council have just replaced all of the sodium lights with LED lights. The cool blue colour and the white light have had a few interesting effects. 1) people are claiming that the lack of birds is now due to the new lights. Although it is well documented that the lights affect animals due to the wavelength of light emitted the latest reasons great ….. they don’t have anywhere to warm their feet on ??!!?? Thats it we should all replace our heating system with sodium lights and hopefully we will have a bright future. 2) the sky is perceivably darker….
The later we can test although i really would like to find out if the heat of the sodium lights was enough to warm birds. Below is 2 shots taken on the same night about 40 mins apart both are 3x 5min subs at ISO 1600 using a 24mm cannon lenses at f5 and tracking on a sky tracker.
The images although of the same region of the sky are also slightly rotated. The image from the back garden clearly has a lot more disturbance in the image. from closer inspection this appears to be caused but potentially high level clouds which were in the area and lights being reflected from them. Although I have tried a couple of times to remove this banding it is nearly impossible in the image due to the extremely high level of ambient light in the original images.
So even though the skies “look” better at home i’m still going to have to travel for the really dark skies. i have not tried the Telescope in the back garden although this may be next