Astro Image Processing - Deep Sky Videos
HTML-код
- Опубликовано: 6 сен 2024
- Nik Szymanek talks us through a few techniques he uses when processing astronomical images, mainly using Photoshop. Nik's website is: ccdland.net
More about Nik's telescope at: • Pear Tree Telescope - ...
More on the people who let us use their images can be found at www.deepskyvide...
Deep Sky Videos website: www.deepskyvide...
Twitter: #!...
Facebook: / deepskyvideos
Flickr: www.flickr.com/...
More about the astronomers in our videos: www.deepskyvide...
Videos by Brady Haran
Editing in this film by Stephen Slater
Love that he's basically pointing out that we have no way of knowing what it looks like until we actually put our eyes on it, so until then artistic license is the name of the game, and I'm all here for it 😍
i know this isnt your type of stuff Brady but i really loved this video on image processing.
weve all seen the photos of space and molecules yet both of those things are almost impossible to see with the naked eye in the raw sense. its great to learn how these images are taken and then processed into what we see on the news etc. space imagery is the most spectacular of all however its the natural beauty of them that make them spectacular
This guy is so amazing. I wish I could use all my time taking such photos.
I recently purchased a 12" dobsonian. I observed the Orion nebula (m42) last night for the first time using this particular size aperture as I previously owned an 8"inch dob. The image looked absolutely breath taking, this telescope exceeded my expectations. Now I have heard that you generally can't see color when looking at Orion unless through photographs or filters and the light is many shades of grey, but I am telling you that m42 looked bright green! It looked like a hd shot. I'm not sure
I believe what Destro is trying to say is that it's an unknown unknown. It is best to try to learn something you don't know, but trying to learn what you don't know really only applies to known unknowns. And so without knowing you don't know, you can't really be faulted for the misconception, or lack of trying to find the unknown that you don't know you don't know. You know? :]
I think Brady has a good question at the end there. The altering of images colour and look means that if we were say, approaching this Nebula in a spaceship (pretty impossible right now, but...) it would look completely different with our eyes than it does in all these photos (or should I say 'Photomanipulations'?) we've taken of them. Isn't a genuine picture better, or aiming to mimic expectation of how our eyes would really see it, if we went there?
I loved the video, I loved the process in Photoshop.
I particularly liked his honesty about the end of the work and the subjectivity of the outcome.
Always nice to watch videos on Channel
I understand what you mean, but also I'm a (beginner) astrophotographer and so I also understand what he means. When looked at through a fairly powerful amateur telescope, to the human eye the Orion Nebula looks like a faint grey wispy cloud - all nebulae do, galaxies too. A camera on a telescope can take long exposures and can gather much more light than the eye can. How the nebula appears depends on how you choose to look at it. Good astro image processing enhances detail without making it up.
You'd see colors. The reason that objects appear greyish to our eyes when we look through telescopes is that our brains only process in black and white when viewing low light objects.
thank you for watching it
It's impossible to make these images look 100% "real".
A human eye would never see the nebula like these pictures show. A human eye just cannot absorb enough light to do a nebula justice.
These pictures basically "compress" all the information about the nebula's colour down into a picture that can be absorbed by human eyes. So the colours and colour differences are real, but you wouldn't necessarily see them if you were staring at the real nebula.
Yeah but there is 0 colour fidelity usually.
thank you for having me!
As for knowing exactly what red - you know because you know exactly what the filter lets through. And all the colours we can see, can be reconstituted from just those three readings.
I've learned so much about nik from these videos and I'm pleased to say, him and i have quite a few similarities
Many thanks for this video Brady, I have always wondered how much processing goes into these images.
Colours are our brain putting "names" on frequencies (or combinations of) in the spectrum. So our brains present us with an image that we can cope with. My green can be your blue.
Colours are also environment or experience based on what we need to navigate our environment. Our brains are plastic in that sence without us noticing the work.
So the notion of what is real become twisted to a personal real or a real real, and this is often the problem we normal people have when we listen to experts.
no, of course nobody's stated it in that way, I'm just using it as a general summary for what someone's implying by saying "Here's the Crab Nebula" or "Look, this is Andromeda" and showing one of these pictures to them.
The person would be thinking that's what it looks like, in colour, but you're saying that in reality if you visited it, far back enough so that your view framed it in the same way as the photo's boundary, and looked upon it with your eyes, you wouldn't see the same thing?
I was wishing someone would ask that final question...good job.
thanks for this wonderful upload...enjoy your work very much
Always nice to see you in my inbox, Brady :)
I still feel his answer to the "real" vs. "pretty" issue was a bit of a dodge.
Of course by "real" one means: If I flew up to the Orion Nebula with my starship and looked out the window, what photo would my experience compare to?
nice work. when I see new video from you it makes me happier :D
More of these please!
you are right about the UI, but the image processing algorithms are better and the 'smart' features are more robust. I work every day with it and since I have upgraded from CS5.5 to CS6 I noticed a significant performance increase. I was thinking that Nik can benefit from an upgrade :)
Amazing, thanks for taking time out to make this video.
More videos with this guy!
That is awesome :) I have yet to view it through a 12" but can imagine that as your light gathering ability increases, so does your ability to see color. Very cool
The protons can not be collected by the eye so the image will look black and white. Even with out a filter and with a DLSR you can capture enough protons on a 5 min exposure to show true colors.
Photo shop and.or other software enables someone to stack images that Will enhance true color.
Even if you try to make it look real... how do you know how it actually looks like without seeing it with the naked eye? I'm fairly convinced that most of the pictures these guys come up with are fairly accurate, but you can never know for certain.
I don't suppose Nik would make his LRGB raw captures available so I could have a go at processing them? I'd like to have a bash! :)
great to hear and I agree!
So i've been lied to whenever i've looked at a picture of distant objects in space all my life .I always thought and imagined the nebula's and distant galaxies to actually look liked they did in there photos but guess its all manipulated stuff with added color to make it look pretty, for all i know the Orion nebula isn't even pinkish in color but some totally random color like dark brown in actuality or some other color.
i can understand aligning the picture because of the time difference.
If you take a black-and-white film/sensor, and you put a red filter (like a piece of red glass) over the lens, the only light that hits the sensor is red. Then you repeat the process with a green filter and a blue filter. Then you've got all the information.
Really, really interesting shit!
Love your videos, Brady :)
What a beautiful nebula, also I always love seeing new videos from your channels arrive in my subbox ;) Your channels really belong to the best of youtube science ;) Thx for educating people Brady :D
Nik is awesome.
hope you like it!
I'd like to see a video on M82 and starburst galaxies!
you need to do a video on the great attractor
Such talent! Love this! Thank you.
very good question brady!!
Using Photoshop is the very last step in astro-photography "Finishing the image" after processing the data ( Image reduction & discarding low subframes, alignment & stacking, histogram stretch & RGB balance )... it's a steep learning curve :D
Im just in to astrophotography and there is a ton to learn. But as for creating an image that is as it looks to the human eye consider: I could sit and photograph the same mountain from the same point and settings every minute. The result would be over 1400 different images. Same mountain but each would show different color/brightness etc.
Great job Brady! don't mind the haters
i guess my question is, what if we were able to use the same filters and methods of capturing an image the man used here to get his final image of space, but instead took pictures of Earth and blended all the filter methods as he did, would the final image look anything like how Earth actually does look like to us? Or same can be done to say a picture of Grand Canyon or Half Dome. Would the method he used be as close to true form of what we naturally capture with our eyes/brain?
So what is a real color of that nebula and others?
This is great, very glad I tuned in!
Is it necessary to use the colour filters? Couldn't we do this like using normal camera? I mean it's a refleting telescope. There aren't the colour misalignment problem due to the difference in refractive index of the same material with photons of different wavelengths.
Heads up! For anyone who find themselves disheartened by the prospect of the piles of money required to acquire the expensive software - there is a lot of professional-quality Open Source Software out there which runs on Linux, which itself is cost-free. You can have all the software, from the Operating System to telescope control, sky atlas and image processing, at no cost, without compromising on quality or usefulness. Start by installing Linux on a PC, and Google the rest from there.
Sorry if this has been answered before, but I had an argument with somebody about the following. If I had a spaceship, and could travel close to this place what Nik was taking the picture of. What would I see? I mean with my own eyes would I see colors, or would it be just greyish?
Like with most nebulae, you'd see nothing at all. While it looks like thick clouds of dust and gas from afar, the particle density per cubic centimeter is still extremely low.
Hil like this nic is great at what he does,
i didnt like the answer to the last question.. is it real, as in, is this how the human eye would see it ? or not ? he kinda avoided to answer
Thats cool, so we could even see the "clouds" and everything? Thanks for your answer!
I'm waiting for the dust to settle, so to speak... we can't add much yet!
More likely it would be a sixtysymbols video than a Deep Sky Video, but not sure yet!
If we would be able to travel to the nebula, what would we see?
Unknown unknowns, things you don't know that you don't know, are actually very real.
You're still not getting it. From what I saw him say, the only reason he thought he was seeing what one would really see, is because he did not know of his unknown. He was wrongly told (it seems) that what he was seeing is completely accurate, and so he didn't know that he didn't know the truth. Do you know about unknown unknowns? Of curse this was "his problem", but it wasn't necessarily his fault.
I got a shiver when he said "shadows"
Brr!
Doesn't the latest gimp only work with 8bit images? Have you tried a fork of gimp, cinepaint or 'film gimp' (which studios used to use for deep painting for films, used on lord of the rings, spiderman etc) or krita, which is mostly for digital painting but can work with 32bit. Both of them are free (as in beer/speech)
When it comes to stars we have the additional problem of not being able to 'see' them properly with our eyes anyway. Our eyes are just not sensitive enough to pick out the colours. Certainly with a telescope we can see the stars and colour. We get the general image of the stars and gas clouds but how we render the colour of the stars or the intensity of that illumination on the gas clouds (dust?) is subjective. BTW If you have a half good DSLR, tripod and computer you can do this kind of work.
fantastic
I don't think it's misconception really, just a case of people not knowing. Wouldn't it be better to educate people that what the photos show and what's there were different? Imagine someone who didn't know a thing about space seeing the photo and being told what it is. If you don't explain to them what they're misconceiving then how will they know they're making a misconception?
someone needs to help this guy improve his website
I was wondering the same thing Brady. As far as "REAL" goes, the way I would ask is, If I were in space looking at this cluster, would it look like that? My guess is, probabaly not.
Brightness is conserved, so no if you went closer it would still be as faint as it is (to your eyes), just larger. The point of this image processing is to concentrate the colours and intensity of the light to something we can see, but crucially it's all from the actual light recorded by the instruments through the telescope, there is no addition of something not there at all, only making what's already there more visible to human eyes.
I wish I had the technology available to try this experiment out. I would really like to see the results. infrared/night vision goggles are the closest thing that combines two filters automatically(?), right?
If you think this is not true even in usual photography. Different objectives with different focuslengths, different shutterspeeds and aperture settings, different films or digital sensors, not talking about the fact that our visualisation is highly brain-based, so imaging can't be real, because what we see also isn't real. Our image processing in the brain is not fundamentally different from photoshopping.
can i get some of those raw files to practice on
Surprised that Nik doesn't use something like PixInsight to process his images
I wonder what such images would look like in stereoscopic 3D.
I wonder what he could do with a "light field camera"?
Windows 98? This guy is awesome.
Can someone tell me how Nik has used photoshop to make the photo?
ha ha... I always look like that before midday! ;)
For the high-pass filter on the image, it's obvious.
About the RGB filtering, I ask myself: Is it a numerical filtering on the graylevel image or there was already RGB value information on this image from the sensor?
I mean, is the RGB filter processing normalize each plane RGB, threshold it, or process on the greylevel image with particular value adapted to the human eye?
+Batfly. About the RGB combine in the image. It is a commom technique in astrophotography, especially in high level CCD image: the Sensor or light detector is actually monochromatic. Actually, every sensor is mono. However, in daily consumer cameras, a RGB matrix is a kind of filter that is added before the sensor. The data is interpolated in the processing, and you have a color image. Hubble and many amateur images do not use the Matrix. The full image is taken separately through Red, Green and Blue filters individually. This yelds better Q.E., basically the image is "brighter" and better, and sharpen as no interpolation is necessary. The R, G and B images are combined afterwards in the PC, as shown in this video.
I hope I've helped and any more questions, ask! The community will try to help, if possible.
cheers
Gabriel
PS: I'm an amateur astrophotographer BTW
That's exactly it.
well if I'd known such important people would be watching....
beautiful, seems complicated
Scratchyrock, that's exactly what I was wondering. Even if a purple earth looked "better" than the actual blue one, I'm not sure I'd say a photographer who produces a picture of a purple earth is doing proper photography.
What does he mean by blending it? Opacity? or?
Windows XP is also lovely.
I cant believe that my nebula photos are actually crap... i have to get PhotoShop and start working on them...
the question brady should of asked was if it consisted with the actuality
Photoshop is amazing.
I think the picture would look better if you captured the screen instead of using a camera. Great video any way.
I guess what technique you are using would depend on what you are looking for, too.
Nik is a really nice guy, but why he is using such a old version of Photoshop :(
he can accomplish so much more with the newest releases
How do you obtain the RGB images?
really? as far as i can tell the only benfit of newer versions of photoshop is a UI change, which is superficial
I don't usually reply to people who wink at me when I am just out of the shower!
interesting
i love telescopes
Just got out the shower in this video Brady? winky face...
5:55 It's Unicron! Flee! Flee for your lives!
Can I make a living off this? If so, PLEASE TELL ME HOW.
I thought the result was quite alot better before his "hour worth of processing"
Клевый мужик :)
W
I need a telescope...
Nice tee shirt Brady !! Like to remind you that the same people who fund NASA also run CIA & NSA so let's keep it on the straight and narrow OK??
Awesome, Now I just need.... a few thousand dollars!!! Time to rob a bank, or mug a fatcat..
Hey how about on a budget?
if that's the case then why can't we show that truth instead of amplifying things in misleading ways and telling kids "here's what space looks like"? I guess we're glamourising it. I mean sure these plumes of gas exist, but if what you're saying is true then nobody would ever see it without some sort of night-vision glasses or a computer mediating their vision. Seems a bit disingenuous to not present reality