Advice needed processing Aurora pictures

[ianwstokes]

I was lucky enough to be in North Scotland a couple of weeks ago when there was some Aurora activity – my first sighting of the ‘Northern Lights’. I drove up into the hills where there was very little light pollution and set up my camera. At first there didn’t seem to be anything to look at so I was just taking a few pictures of the stars. After about 20 minutes I noticed what I thought was a feint, grey layer of mist above the hills. On inspecting my shot, what I thought was a grey mist was showing green in the picture. Over the next few minutes the band of light became more prominent and started to show vertical banding– obviously the aurora.

 

The top image is the camera version of the aurora. I was using the raw file format so there was no strange scene processing in the camera and it’s what I expected from the pictures you see published. In the lower picture I’ve de-saturated the colour to how I really saw the spectacle in the hills.

 

So my dilemma is – how to process my images. Do I upload the pictures as they come from the camera or reduce the colour to represent what I saw?

 

Does anyone have an explanation for the difference?

[hvbemmel]

found this on the web. doesn´t answer your questions entirely but it gives a lot of info
http://www.aurora-service.eu/aurora-school/how-to-photograph-the-aurora/
http://www.aurora-service.eu/aurora-school/photograph-auroras-ii/

[ianwstokes]

Thanks for the link Herman. There’s some useful information I wish I’d seen two weeks ago! Part 2 gives some good guidance on how to treat the colour in the images and gives me a standard I can adopt with my pictures.

 

I’ve done a bit of searching as to why there is a difference between why I saw very little colour compared to the camera. The link below explains how our eyes don’t perceive colour at low light levels – this looks as though it could be the reason for the differences.

 

http://web.atmos.ucla.edu/~fovell/AS3/theory_of_color.html

 

What I need now is another trip North – although I don’t expect I’ll get so lucky next time.

[© Tom Cooper]

I have only seen aurora once, about 12 years ago.  There was some color, but there was more color in my photos.

Science lesson:  The problem is that at low light levels, the human eye loses most of it's ability to see color.  There are two types of light receptors in our eyes, rods and cones.  The rods cannot see color, while the cones are what give us color vision.  Those cones have to have plenty of light to activate, and so they work best in the daytime.  At night, they barely participate in our vision.  The rods, on the other hand, become gradually more sensitive in the dark.  As the night goes on, they give us better and better vision.  It took 20 minutes before you started seeing the "mist above the hills."  That's because it took that long for the rods to "gear up" and start showing it to you.  It can take about three hours of near total darkness for the rods to reach maximum sensitivity.  While the cones gain a little sensitivity in the dark, they will never catch up to the rods.

So when your eyes adjust to the dark, you have dramatically reduced color vision.  Your camera isn't lying to you, but your eyes can't show you what is there.

My opinion: You have three choices, not two.  You can try to show it as you saw it (visual documentation), show it as the camera recorded it (technical documentation), or you can play with it (artistic representation).  No matter which way you go, someone will think it wrong, and someone else will think it right. 

My advice:  Make sure you are pleased with the results, and don't worry about what others have to say.

Tom

[ianwstokes]

Thanks for the analysis Tom, I especially liked:

"No matter which way you go, someone will think it wrong, and someone else will think it right."

very perceptive. I think I'll go with the 'technical documentation' approach.

Ian