Luis Argerich - Astrophotography | The Processing and Over Processing of Night Sky Images
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The Processing and Over Processing of Night Sky Images

April 30, 2012  •  3 Comments

I will start this small article with my premise:

“If you over-process a night sky image to the point of destruction it will have better results for the general public”

To make my point more clear I will show what I mean with a couple of images. I will start with this photo I took of the Winter Milky Way from the South Hemisphere:

This is a photo I like. It was taken from a very dark location away from light pollution and shows the beauty of the Milky Way from Carina to Scorpius. Dark nebulas as the pipe nebula in Scorpius or the Coalsack nebula in Crux are clearly visible. Other nebulas as the Lagoon (M8) and Triffid can also be identified. The image shows the Milky Way brighter than what can be seen with our eyes because the camera is more sensitive to light but there’s not a huge difference.  For an observer that was in that place this photo will be a good representation of what he saw and felt at that moment.

Now let’s apply a lot of contrast, saturation and sharpening to that very same image. The result is this:

In astronomical and photographical terms the photo is now destroyed. The sky is never pitch black as the photo shows it, the Milky way is never that bright, the fine details are gone and everything is now reduced to a bright blob of light against a very dark sky. It sounds terrible and it is terrible but believe me that the general public will prefer this overdone image to the original. And I also think I didn’t overdo the image enough, more damage can be done and more “spectacular” the photo will be.

I’m not going to do the experiment of uploading both photos to photo-sharing communities because I don’t like to use my viewers as Guinea Pigs but I’m totally convinced that the overprocessed image would win the battle by a huge margin.

So why is this happening? I think it is because the public, without a knowledge of astronomy, is likely to believe in almost any image of the night sky you present as something real. They have not enough knowledge of the sky or astronomy to say the photo was totally overdone.

If you present a photo of a green cow the general public will reject it saying things as “I like the photo but not the processing”, “This is not real”, “overdone”, “photoshopped” and if they have a bad day you can get something as “this is not photography”. Been there, done that.

This happens because everybody knows cows are not green, so when they see a green cow they know the image has been manipulated and they feel the photographer tried to fool them, the result is a rejection towards the photo. If you do the same with a night sky image presenting a bright green Milky Way arching above the hills of a landscape the public will love it. They just don’t know the Milky way can’t be that bright, they just don’t know it is not green and they just don’t know what astronomical features were destroyed in the processing. So without a reason to think the photo is overdone they will just admire what they see and love the photo. The comments will be “stunning”, “I never thought the sky could be so beautiful”, “your location has some amazing skies” and so on.

Even photographers will think the photo is great because they can’t tell the degree of processing applied if they don’t know hoq the real thing is. When photographers without any familiarity with the night sky start their journey in astrophotography or night landscapes they tend to overprocess the images too. This is easy to explain as they try to produce with the photos the result they will like as vieweres.

So what happens if you are a photographer with a knowledge of astronomy? Do you try to keep your photos honest and real but with your artistic touch or do you just overprocess the photo to the point of destruction to impress the public? To be honest I have no idea of the answer to this question.

As an example Iwas asked to present some photos for an exhibit recently and I had to decide between honest photos with a low impact to the public or destroyed photos to generate some “wows” I went with the first option because I need to like my photos too but from a sales, marketing or visibility point of view that’s certainly the wrong decision.

This is a view of the Milky Way above a lake in Patagonia. I took the artistic license to make the sky a little more blue than what it really was but there’s not a huge difference from the real thing. The Magellan clouds are visible on the left and they have the brightness that matches what you would see from such a dark location. There are even some traces of airglow near the horizon, that’s the brightness of earth’s atmosphere and it can only be seen in very dark places without light pollution. You can see them as bands or streaks in a greenish color. I was there and the photo represents what I saw, and what I liked in a good way.

It’s interesting in astronomical terms and I hope it’s also a beautiful view of the night sky, but can I do it better? worst?

When I show this overdone version people say “wow” they point how bright the Milky Way and the Magellan Clouds are, they ask about the location, and viewers with good eyes signal there’s a hint of “aurora” at the horizon. I can either be happy with that or just embarrassed because nothing they say is real and the photo has been destroyed. The big Magellan cloud looks like a light tube up there, I feel terrible to even show this as an exercise but print this photo big in metal paper and you have a winner. You will see people gathered around the photo, you will see photographers that want to take a workshop with you and there’s a chance you can even win some contests with such a photo, it’s novelty, it’s unique, it’s bright, it’s destroyed.

If an astronomer sees the photo, professional or amateur he will be  disgusted. But how many astronomers do you see around you now? As I say “you can’t argue with success”.

If you browse online you will find plenty of images of the Milky Way and other night sky features described as “stunning” when they are actually overprocessed shots to the point of destruction. The question is how many viewers notice that and if that is or not important to the photographer. In most cases the photographer is honest with his own processing, he just doesn’t know he is destroying the sky in the photo, he processes until he likes it. Honest photo, honest viewers, but nothing is real.

This is something that I have been thinking in the last weeks and I think it can create an interesting debate about what is the right way to go. It’s a terrible Dr Jekill and Mr Hyde feeling, I know I can make my photos more succesful if I just make them more horrible to me.

Maybe this is in some way similar to what happens with HDR. The general public loves HDRs, they are bold, bright and they look very real but many photographers don’t because they know the image is overdone to a point they don’t like it any more. So what do you do? Do you process to your likes or do you process to be succesful? Believe me you don’t want to feel that way.

If you ask me I prefer to avoid the wow factor and I hope the viewer can get interested in the night sky and learn how many beautiful things can be seen out there, the importance to fight against light pollution and that if the photo is honest there’s probably a lot to learn from it and that it can be beautiful too. If I get a “wow” from a photo that I know is not overdone then I will feel really good, the only problem is for that to happen I need to go thru many many low impact photos when I could just do a little overprocessing. The debate is now open.


I agree with your overprocessing comment.
Do you mind sharing which lens you have used here for the 1st picture?
I am also curious to know what is your fav lens (between 14mm to 40mm) for milkyway shots.
This is something I've struggled with, too. I see some fantastic astronomic shots out there on the interwebs, and I've been striving to do the same. I know the concepts, the math, the settings--yet I am never happy with what I "produce." When I post for friends to see I do get the oohs and ahs, but I feel like I'm cheating, because I've had to tweak them. I do the same with my landscape HDR shots, but my goal is to make it look as natural as possible--I dislike the obvious HDR. But then, like you said, the vast majority of viewers don't even know what the proton-proton reaction is, they don't care, and if you're going for "effect" then you have to.

That said, I do the best I can with the equipment I have--a Canon 7D and a Tokina 16-28 f2.8. It's what I could afford. I'm still learning the processing--and struggling with that fine line between overdoing it and something that only I can appreciate because I was there.
I agree with you. I prefer the more realistic version than the unrealistic processed one. You have some beautiful photography my friend. Thank you for sharing. I hope to shoot the milky way too in the near future.
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