Another Revision Example
The original northern lights image (www.flickr.com/photos/79387036@N07/23645466565/in/album-7...) is considerably enhanced to bring out the shadows and improve on color balance, with this revision.
Red aurora is rare at high latitudes so when this occurred, I took lots of exposures. In the day of film, the spectrum of color was not always captured accurately. In this version which occurred at the on-set of twilight, I managed to record the aurora lit by the first rays of the sun. That purple-blue is this resulting phenomena.
More specifically: This photo is taken shortly before sunrise, when the sun illuminates the upper part of the aurora. Ions that are produced by the aurora at these altitudes scatter the blue part of the sunlight, causing the upper edge of the aurora to look blue.
Another Revision Example
The original northern lights image (www.flickr.com/photos/79387036@N07/23645466565/in/album-7...) is considerably enhanced to bring out the shadows and improve on color balance, with this revision.
Red aurora is rare at high latitudes so when this occurred, I took lots of exposures. In the day of film, the spectrum of color was not always captured accurately. In this version which occurred at the on-set of twilight, I managed to record the aurora lit by the first rays of the sun. That purple-blue is this resulting phenomena.
More specifically: This photo is taken shortly before sunrise, when the sun illuminates the upper part of the aurora. Ions that are produced by the aurora at these altitudes scatter the blue part of the sunlight, causing the upper edge of the aurora to look blue.