is astrophotography cheating?

[seven_legs]

I know that I am going to get burnt at the stake for asking the question but I need to ask:).

I am thinking of getting into widefield and close up moon astrophotography(one shots). having seen some great photos on this forum I cannot help but be inspired. but when I seen have many stacks, darks and whatever else has been done to the image it makes me think. for example a noobie will see a image of Jupiter through a 8 inch scope and think wow that's amazing( which it is). but be disappointed when they buy a 8 inch scope and look at Jupiter through the eyepiece.

I just asking is modern astrophotography a bit like models on a cover of a magazine being airbrushed to looked better that they are, if you know want I mean?

right, time to get a false identity and leave the country...

[Psychobilly]

I tend to take the  view it as using technology to overcome the limitations of the Mk I Eyeball....  

There are very skilled observers out there (an on here) that get plenty of enjoyment and make careful observations and records  out using the same said Mk I eyeball and I take my hat off to them...

What I don't agree with is when scope manufacturers create un-realistic expectations by putting glossy colorful images on their "department store" scope boxes and claim huge magnification potential...

Peter...

[Thalestris24]

Cheating? Absolutely not! Essentially it's science in action - collecting photons from however many light years distant and using them to make the most accurate representation that you can by minimizing noise and selectively stretching the data to reveal faint detail. Nobody artificially adds to the raw data that is collected but simply manipulating to best visual advantage seems fine to me. The eye isn't sensitive enough to see the detail, depth and colour that digital sensors can detect so it wouldn't be possible to see all the stuff in the universe without some sort of photography. The guys at NASA spend months putting Hubble images together and Hubble himself relied on photographic plates.

Louise

[seven_legs]

true.

 I can under using art programs for image of comets, if you want pinpoint stars and a nice image of the comet to merge them together.

[starnut]

You could ask the same question why do we spend thousands of pounds on equipment when all the best images on on the internet are for free.

[Physopto]

I know that I am going to get burnt at the stake for asking the question but I need to ask:).

I am thinking of getting into widefield and close up moon astrophotography(one shots). having seen some great photos on this forum I cannot help but be inspired. but when I seen have many stacks, darks and whatever else has been done to the image it makes me think. for example a noobie will see a image of Jupiter through a 8 inch scope and think wow that's amazing( which it is). but be disappointed when they buy a 8 inch scope and look at Jupiter through the eyepiece.

I just asking is modern astrophotography a bit like models on a cover of a magazine being airbrushed to looked better that they are, if you know want I mean?

right, time to get a false identity and leave the country...

Hi,

No definitely not cheating! It is time consuming, it requires patience, It can require a lot of the green stuff, it can require a very forgiving  nice wife  (if married), it requires a lot of "now how the heck do I do that?

BUT if you really get stuck into it the time will pass and not be noticed. The house will fall into disrepair  . The kids will no longer recognise you  .

But you will mostly be happy, maybe broke    BUT HAPPY

Derek

[Scott]

models have bits added/removed quite often to the point that they don't know themselves what they look like. Astropics are not adding anything. merely revealing what is already there.

thats my take anyways

of course comparing ap to visual is pointless in as much the same way as comparing two watersports such as canoeing and jetskiing is pointless

[strutsinaction]

You could ask the same question why do we spend thousands of pounds on equipment when all the best images on on the internet are for free.

You sound like my wife!

[Physopto]

Cheating? Absolutely not! Essentially it's science in action - collecting photons from however many light years distant and using them to make the most accurate representation that you can by minimizing noise and selectively stretching the data to reveal faint detail. Nobody artificially adds to the raw data that is collected but simply manipulating to best visual advantage seems fine to me. The eye isn't sensitive enough to see the detail, depth and colour that digital sensors can detect so it wouldn't be possible to see all the stuff in the universe without some sort of photography. The guys at NASA spend months putting Hubble images together and Hubble himself relied on photographic plates.

Louise

Hi Louise,

Just think of all those poor photons that go to waste when we don't see them!

Derek

[gkec]

I think the OP has a point.  Using photographic plates and later electronic detectors has progressed astronomy from being early blind to seeing the edge of the universe.  Of that there is no question.  A simple experiment is to look at M42 through a scope and then take progressively longer and longer exposures to show how powerful photography or more precisely electronic detectors are.

This has revolutionised astronomy in the last 100 years.

For scientific astronomy you need raw data.  Every detector has  a frequency response that can be characterised but that can't be changed.  So you have to allow for that.  In transferring the information from the detector to "storage" for the acquisition of proper scientific data the mechanism should not interfere with the data.  More prosaically the electronics should be designed to obtain as accurate a reading of each pixel (in the case of a CCD) as possible inducing as little noise as possible.  

You then have a raw image.  It is perfectly valid to stack images to increase the signal to noise ratio,  remove dark frames etc..

Up to this point the camera has been used as a detector.

The data in it's raw form is most useful scientifically.

However, then the data is shipped into photoshop or equivalent or more increasing these days processed in the camera.  At this point the data is scientifically compromised. 

This is because the dynamic range of the image usually far exceeds the ability of being able to present the information visually and completely.

In simple terms how do you display a 16 bit monochrome image or a 16 bit RGB image without losing visual information.  (Computer graphics tend to be 8 bit).

There are translation techniques that work without destroying the data but these rely on false colour and don't give a good visual representation of the image.  

So then there are techniques to present this information visually.  However this compromises the scientific usefulness of the data.

"Photoshopping" is then an exercise in aesthetics.  How to make the "look good". There is nothing wrong with this,this is what astrophotography is.  It is not quite airbrushing models but it is analogous to it.  

[ollypenrice]

You say 'Stacks, darks, flats and whatever else.' Let's break this down.

Darks show the fixed pattern noise (errors) that are inherent in your images every time. They shouldn't be there. They don't come from the sky, they are created by the camera. All you do when you apply darks is subtract them from the picture, making it more accurate. This is plain calibration of your equipment and is standard practice in science.

Stacks are images made not from one exposure but from many. Darks do not get rid of all noise (error) because some of it is random. By taking the same picture many times and averaging the result you get the random noise to cancel itself out, making the picture more accurate.

Flats are photographs of the optical defects in your scope's lightpath. All scopes and lenses will give a brighter middle than corners. This is an error. By photographing these errors you can ask the software to correct them, brightening the corners and dimming the middle till they represent the true nature of the light coming down the spout.

So far, then, we have simply tried to remove our system errors from the picure.

Now the dreaded word 'Photoshop.' We don't use airbrushes in Photoshop. We don't paint things in or make them up. What we do do, though, is manipulate the dynamic range of an image. As it is recorded the data is fairly close to linear even in amateur CCD cameras and very close in some. That means that an onject half as bright as another object looks half as bright. While this might sound OK it is, pictorially, pretty dull. The faint nebulosity we have captured is so little brighter than the background sky that we can't see it. If we 'stretch' the data we change the linear brightness distribution to a non linear one, so the brightness of the faint nebulosity now rises above the background sky and we can see it. But we didn't invent it or paint it in, whe just revealed it. 

It would be crazy to call this cheating. It is the whole point of doing it! The idea in astrophotography is not to replicate the eyeball view, it is to reveal what the eyeball cannot view.

But any manufacturer implying, by whatever means, that their scope can show to the eye what it can show to the camera is certainly cheating.

Olly

[sgazer]

Not unless using a scope is cheating as it allows you to see more than with the naked eye!

With Astrophotography, you are not drawing the image in photoshop as the celeb mags do, you are increasing the clarify of the information that's alrrady there, so the eye can see it, a bit like a scope.

You capture photos which are turned into electrical signals and thus an image. You use calibration frames and stacking to reduce the deficiencies of the sensor. Then you stretch the levels so your eye can see a bigger difference between grey levels. Generally, you don't get the paint brush and start adding stuff that was never there in the first place.

[Dave Lloyd]

Hardly cheating. If you want to see that level of detail there's no alternative.

[ronin]

I suspect there is an arguement that it is not cheating but it can mislead a person.

Equally I have read posts where the question is "Galaxy X looks nothing like the image on the Chandra image site!"

Then trying to explain that Chandra is an X-Ray telescope means you cannot actually see that image immaterial of the scope.

In photography, wildlife, landscape etc, we are used to taking a photograph that looks like the object, in astronomy that is not necessarily correct.

Most imagers are reasonable, they won't burn you at the stake.

They much prefer staking you out over an ant hill these days.

Creates less CO2 that way.