2:29 Camera Set up 3:29 *1 image* 4:01 Crush the black with Curve adj 4:41 Minimal anatomy of Orion neb to start 6:39 Defn. of Noise, then 9:57 S/N ratio 7:18 Beneficial effect of "Mean" in stacking 8:26 The merit of Mean, explanation 6:47 *16 image group* > 11:37 9:57 Signal to Noise ration 10:17 Why S/N ratio improves with Stacking - Proportion 11:58 Horsehead neb in 16 image 12:19 Running man neb in 16 image 13:09 Witchhead neb in 16 images - Not yet visible 13:44 Recentering - 64 image group 14:24 Software to Recenter/align moving object images automatically 15:19 RAW file Liniar to gamma correction stretch/curve 17:24 *16 to 64* stack comparison 18:47 Flame & Horsehead neb details 19:41 Orion neb 20:13 Witchhead now showing up in 64 group 20:43 64 compare to 264 - 21:31 20:54 Angelfish nebula next to Betelgeuse 21:05 Barnard's Loop (catalogue designation Sh 2-276) 22:18 Dim object improvement - Witchhead 22:57 *256 to 1024* Total Integration of 34 minutes 24:08 Improvements in dust neb features 24:43 Boogeyman nebula 25:07 M78 reflection 25:35 Flame/Horsehead 25:51 Orion neb 26:36 Witchhead 25:56 *Comparison of all groupings* 28:08 Boogeyman neb 28:50 Barnard's loop 29:49 M78 30:35 Flame neb 31:32 Horsehead neb 31:53 Runningman neb 32:47 Orion neb (Messier 42, M42, or NGC 1976) 34:08 Where More can help 34:38 Star halo around Rigel, improvement with integration 35:08 Witchhead's chin, nose, and eye 35:59 Moral of the story
What's even more stupid is that i went ahead and stacked it AND THE GALAXIES WERE REASONABLY RESOLVED -COMPLETELY UNTRACKED FROM BORTLE 9 😑. If it was RAW......
This is the clearest explanation of stacking I've seen on TH-cam. I've watched a few of your videos before, but after this one, I'm a subscriber. Thanks for clarifying.
@@115justus No. You don't need the latest and greatest gear to take amazing images, you just need to know what you're doing. Sure, if you handhold your phone up at the sky, don't expect any amazing results, but that's not what phones were designed for anyway. But a cheap second hand camera like a Sony a6000 and a fast lens (something affordable, like a Sigma f/1.4 prime, 16, 30 or 50 mm) can achieve amazing results - if you know what you're doing.
@@115justus $6K is not needed. A total of $1k using a dedicated astro camera and astro telescope would get you even better results. But skills is also required.
@@NebulaPhotos I have a question, is stacked 1024 photos(integration of 34 min) yield same result as 1 34min long exposure(assume it's possible with tracker and not considering the hot pixels)? I guess what I want to know is in general, is it better to stack more photos with shorter exposures or to stack less photos with longer exposures with same integrated time? Or do they have the same result? Thank you!
@@leezheng8161 Generally fewer photos with longer exposures is better than many shorter exposures. I explored this idea in this video: th-cam.com/video/mYucAuUrdTs/w-d-xo.html
@@NebulaPhotos oh great thank you! I will check it out. Btw, I am from Boston area too. I often shoot at Nubble, Cape Cod and White Mountains. Hope will bump into you one day haha.
This is Definitely the best video yet on your channel .I am sure it is gonna be more popular than your Andromeda shot .Defining the meaning of astrophotography concept really made this video a lot better .
I'm not a photographer, but I have so much respect for people who can capture the sky like this. Also, can we give a shout out to those amazing programmers who have designed software like this?
What a quality work! Bravo! The explanation of signal to noise was enlightening. I've done signal processing since grad school but for some reason, the simplicity of the explanation felt like "eye opening" although I know this stuff close to heart.
Nico, thank you for this excellent video! It has pushed me over the top to support you on Patreon at the highest (Seagull Nebula) tier. I started exploring astrophotography just over a year ago, and your videos have provided a helpful guide along the way. Comparison videos like this finally provide the means to understand why astrophotography imaging and processing practices are what they are. They help me understand how to improve within the limitations of my environment, equipment, and software -- and what additions/upgrades to consider. A similar comparison of various exposure lengths to achieve the same total integration would be nice, as would a comparison of the same targets using a dedicated and a non-dedicated (Ha-filtered) camera with all other parameters the same. Keep up the great work!
I am totally new to astrophotography and you provided great explanations throughout the video. I appreciate it. Well done you've earned my subscription.
Great Video. Thanks Nico. While there are a lot of good videos on the net, it has been you and Trevor from astro backyard that have helped me the most. In a few months I have acquired a T3i and astro modified it myself. With a entry level tracking mount and my camera piggybacked on my scope, with a 55 to 250mm kit lens, I have gotten impressive images of The Pleiades, Flame, Horsehead, Running Man, and Orion Nebula, as well as a very detailed image of Andromeda Galaxy that is 1000 times better than I ever expected I could. Thank you very much. Your videos are an amazing tool for a beginner like me...
@Jim Lewandowski I think you will love it. I was amazed at how much more light it collected after the mod, especially in the IR end of the spectrum. It seems like it boosted UV a little bit as well as I got a little more detail on the Pleiades Nebulae after the mod with the same exposure times. I also use a IR/UV cut filter with a custom white balance and take decent wildlife shots with it. Just a great camera for the price. My next camera will be a 60D which is very affordable used and just as easy to modify. Should be even better...
@@lepetitbaigneur9073, I use the Explorer Scientific iEXOS-100-2. It is a great little mount for the money (paid $499). Can track up to 90 second exposures with a quick alignment using the sight tube. Still haven't gotten a polar scope, but that should make it even better...
Great video Nico, I just love your enthusiasm for the subject and that really comes across in your presentations. I am only one month into my astrophotography journey and my first object was Orion. With your videos and those from AstroBackyard, I really have found loads of tips and tricks. I did find your explaination of signal/noise ratio in this video very informative. I have a SWSA, a Canon EOS 60D and a Samyang 135mm lens (all purchased just for this hobby), but what I really need is some cloudless nights (in my current bortle 9 location).
Nice comparison and a good illustration of what’s possible with basic gear. You didn’t really talk about your f/1.2 lens but that makes a huge difference compared to the more common f/2.8 or f/4 lenses since you’re getting a lot more light to the sensor. Someone with a slower lens would need to increase the number of frames by a factor of four or eight to achieve comparable results.
Good point. And even for fast lenses you may need to stop them down to f/2 or f/2.8 depending on the lens quality. My Samyang (Rokinon) 135mm f/2 is producing strange starshapes on the edges on f/2 so I usually stop down to f/2.8.
Another thing to note is that he's using a camera that is factory "modded" to let through more light of certain wavelengths which is super useful for astro photography. A regular camera will not be as sensitive.
Does that mean we need more total exposure time with an f4 lens ? Or is total exposure time the same regardless of what settings are applied ?(eg; 1 hour total exposure is more than sufficient)?
@@Photographersforyou Yes, you'd need more total exposure time. I'd even argue that it doesn't scale linearly, as slower lenses give a worse S/N ratio for the same individual (per-frame) exposure time, making it harder to separate the two during processing.
@@tosvus This was the question I had after I watched the video. I tried to shoot Bernard's loop last night with a 50mm 1.8 and did around 10 minutes of exposure, but I couldn't see ANY of the loop or darker nebulae even after stacking and aggressive processing. I was using a stock Canon T7 though, so I figured that was the reason.
Thank you for making the concepts and process easily digestible. I'm new to this hobby, and had some very general understanding of "stuff", but this video helped it all to become clearer and more understandable.
Insanely well explained. Didn’t even know I wanted to know this but just found out a lot more about my cameras, even if you talked about Nebula photography. Makes me want to find a dark sky somewhere. New sub!
Have to say that even tho I have been imaging through a telescope with an equatorial mount for a good while, I still really like these "entry level" videos that you make. You have a great way of explaining the concepts and your videos are just a pleasure to watch.
Well done Nico. I got 'sucked in' to watching it because it was so good, especially the your individual pixel - signal to noise ratio explanations in the beginning. I wish you would have made this video five years ago. Cheers Kurt
@@Cozfx Sorry that's just a myth. ISO is like a VU meter indicating the volume of an audio amplifier. If you have to turn up the Volume control to where VU meter needle is pointing in the red area to be able to hear, it means the audio input from the preamp is too low. Similarly if you must use HIGH ISO it means your settings of Aperture and Shutter speed are wrong or you have not added more light (like using a flash). If you plug in a mic to line-in, the signal to the power amplifier will be too low. Cranking up the amplifier power will only increase distortion due to low signal to noise ratio. The Lens and Shutter speed settings are like setting the LIGHT preamp to the sensor. Wrong settings of Aperture and Shutter speed created the noise. NOT HIGH ISO.
Thank you so much for making videos, I don't know what I would do without these in depth videos explaining what everything is for and what it dose for using DSS.
I'm a newbie to astrophotography this video has really helped me to understand the importance of stacking and the usefulness of shorter exposures. I'm excited to try it myself
Hey, thanks. I was really interested in learning more about this. I first hear about this strategy seeing an awesome shot in a gallery and had no idea what it meant!!
I been searching for tutorials, but most of them are just showing me how to do it and was never defined tis clear on how it works. This video explained everything I need to learn. Thank you!!!
well done, such a stunning video! i was not thinking to take such photos before, but after seening your video i´m super excited to try it out too, thank you Nico!
So welldone Nico. I did once last year with my fuji xt3 + tripod + nikkor 80-200 f/4 ais. I stacked 900 photos in 3200 iso + 0,7" ss + f/4.0 + 200mm. It spent about 25 hours for stacking each time i stacked. I used both Sequator and Deepskystacker but i prefered sequator result. Final photo was pretty good but your really surprise me.
A video on his other factors affect that signal to noise ratio would be cool - like taking a one minute tracked exposure vs 30 two second exposures .. or different ISO comparisons etc
I can answer that rn. If your read noise is high you will never have the same quality, ever. In high LP its not that bog a deal but in low LP it takes a lot more time to swamp out the readnoise with data so longer exposures are far superiour. Different iso? Iso will affect read noise at cost of dynamic range, so its basically a balance, with 2s exposures high iso is benefitial
Nico this is such an awesome instructional. I love how you simplified the process of how photons work. Most people just know taking several subs and stacking works but not really how or why and what’s happening. All the visual astronomers who say all my images are photoshopped and faked need to see this. 😂
I gotta give it to you; I didn't understand stacking before watching this video, and I've always thought that astrophotographers actively colour and paint the photos. Thank you for showing us how much difference you can actually get by taking more photos and stacking them. I thoroughly appreciated this!
As far as i know this was the most well illustrated explanation. The youtuber "Catching Photons" also provides a really great explanation of this with all the theory, but your video has a great balance of theory and practice.
You're really bringing out my inner geek with these excellent videos, I personally love the science and aesthetics of astrophotography (my new hobby) going to order a star adventurer pro v.soon too. Just so friggin amazing to me when I see another galaxy and think what the hell it actually is, billions of suns and planets just there like a smudge on the lens almost. Far out!!
I would like to see a comparison between images of the same total integration time but where each image is comprised of a different number of frames if you haven't done that already. For example: compare 900*2 second exposures and 3*10 minute exposures if you have the equipment for that and see what the difference is.
How does an image get 'brighter' when every sub exposure is the same(time)? I know you 'stack' them, but how are you getting additional data on a pixel if it has the same amount of light hitting it?
That is what this video was trying to answer, but let me try in different words. Stacking has a cumulative effect so instead of capturing the photons hitting that spot over just 2 seconds you are combining all the photons that hit in that spot over the total integration time. In the case of my stack of 1,024, all the photons in 34 minutes. Photons don't arrive at a steady rate, but instead randomly, we call this random accumulation 'shot noise.' By capturing more photons, we lower the proportion of noise in the final photo, so you have more signal and the signal to noise ratio is better.
@@NebulaPhotos So, the pixels that recieve photons are 'stacked' while unexposed pixels get clipped, sort of like masking them off of each layer? *************** I didn't know that photons were random until I watched the rest of the video. I typed my question before I finished it. Thanks so much for replying and the very informative videos.
Very educating video. Thanks Nico. But I was wondering: you stacked 64 images, resulting in like 8 minutes of exposure. Can we get the same result - with tracking of course - by exposing 8 minutes (same ISO etc.)? And thus we could get your 1024 stacked result by stacking 16 of those? Also: I really only like the 1024-stack result because of the spectacular details.
Yes, not only the same result, but a better result. I don't really delve into in this video, but there are some drawbacks to using such short exposures having to do with camera noise (readout noise). With longer tracked exposures, you avoid those drawbacks, and will have a slightly better stack with equal integration.
Super interesting. I have enjoyed astrophotography for a while now but I didn't know that nebulas could be seen to that degree without a star tracker. Thank you for the theory as well.
This is absolutely amazing! Good work, and nice explanation. By the way, there is another advantage of stacking: Compared to images taken using tracking, you're additionally averaging out differences in the CCD's pixels. Assumed one pixel (one CCD cell) has a slightly different sensitivity than its neighbor, this difference would add up when you track with the stars, because you would force the light of one small star hit always the same pixel. When you pick your frame quasi-randomly, this does not occur. Unfortunately, the noise you record does not only come from too few photons, it's also generated in the image sensor itself, caused by temperature (that's why they do so many efforts to keep the JWST's camera at very VERY low temperature), so tracking can have advantages as well. But that could be a different video.
Hi Nico, great videos. I guess what you're saying is when you aline and stack multiple exposures you doing the same thing as taking one exposure.for the same amount of time. Seems to me shooting the shy at night is the same as shooting a landscape during the day, somewhat, both are made up of different light "intensities"; suns or stars transmit brighter "light" then say what they call the dust reflects.Cameras have a unique ability to change the intensity or actually "force" of light; the longer you leave your lens open the brighter things become: (I shouldn't use the term "force" because then you have to get into how light, electromagnetic frequencies, are created, and I don't think the text books are going to explain that right). Forces, seismic, electromagnetic, ocean, etc are the one aspect of "nature" that are not studied yet, and I find that unfortunate because they might explain the vary creation of everything; except for our souls of course. Thanks for the great tips, and keep up the wonderful videos,
Hi Robert, Yes, you got it. One long exposure and a stack of many sub-exposures are not technically the same thing, but they are functionally equivalent. In both cases, it is about collecting more light.
Nico, great explanation again! I've just joined your patreon because what you do is 100% the best I've found. You've helped me massively, I actually gave up AP for a few years as I couldn't get the hang of it but thanks to your superb tutorials I'm right back into it again. My astronomy club at the school where I teach has loved them too. Do you work with FITS files much? We're using the Faulkes Telescope Project's North observatory in Hawai'i and the learning curve with processing them is not for the daunted!
I have to say this video was flawless!! I mean perfect, thank you so much 🤩🙏 You made 38 minutes feel like 10 👌 I will deffenitly try to shoot a nebula some night 🌌👍
Another fantastic video Nico. So informative. Would you consider doing a Photoshop processing video to demonstrate how to achieve a SHO Hubble pallet with a OSC camera? I would like to learn how to do this. I use either my 2600 MC Pro or Canon RP with an L-Extreme filter. Thanks. Dr B from Manitoba, Canada
Something to note: stacking isn't somehow "cheating" compared to a true long exposure photo, because a digital camera takes long exposures by stacking internally anyway. So whether it's done inside of the camera or outside really doesn't make much of a difference. I think manual stacking makes more sense, because taking a lot of short-exposure photos and combining them is simpler than taking one long tracked exposure with a strong filter in front of the lens. Simpler and less error-prone
Nico, excellent. Have you tried Blend If in your layer properties to avoid blowing out the core of the Orion Nebula and bright stars? On the Underlying layer alt click the white carat to split it and drag the left half to the left.
Nico, you are so awesome! I not only signed up for your site, also Helena's too (I left her and all and inspiring message). Hey, I am just starting out in astrophotography ... and the both of you are all I need to learn and grow. Well, more you than ever since we live in the same US of A! Your my mentor and I am your student. You explain everything nicely, like English we can understand. Looking forward to more videos. Keep up the great work! Richard, Ramona, California
Very nice video. Now I just need to decide if I want to focus on using my canon 50mm lens and cropping or used my 75 -300 kit lens with way less crop. I'm thinking the 50mm will make much nicer looking stars.
Noise is not the random amount of photons hitting the sensor but the random noise each electronic part generates. I like the deep comparison of the different number of stacked images you show. It is very interesting to see that. Great work!
Those kinds of noise (thermal noise, readout noise) are not covered in this video, but in deep sky imaging make up a smaller percentage of the total noise than shot noise (random photon accumulation). Shot noise is why we stack. Thermal noise noise only goes up with longer exposure, but we have a different strategy for that called dark frames, again not mentioned in this video, but you can watch my longer videos to hear about calibration and more details on the process. Cheers, Nico
@@NebulaPhotos You can always learn something new! Thanks man! Found this formular describing the signal to noise ratio (SNR) that made things much clearer. SNR = P Qe t / (P Qe t + Dt + Nr^2)^(1/2) where P is the incident photon flux (photons/pixel/second), Q(e) represents the CCD quantum efficiency, t is the integration time (seconds), D is the dark current value (electrons/pixel/second), and N(r) represents read noise (electrons rms/pixel). Never thought about that the contribution of P would be so big. I always thought that the other effects of Q, D, and N are much more dominant.
I've tried loads of different tutorials before and none have been helpful at all. Thanks for this easy to understand and follow explanation. Much appreciated!!
Really great video! Based on this method, what do you think about "lucky imaging" for deep sky objects? Any chance that you make a video about this topic too?
This is the best astrophotography video I've ever seen on TH-cam. Seriously good job dude. Makes me excited to try it myself. Did you have it on a continuous self timer with a two second interval?
A lot of that background noise isn't even sky photons coming in to excite the pixel sensor as you mentioned at 6:18. Noise will enter the video data channel through other sources like the the tendency for electrons to jump through the bandgap spontaneously instead of by excitation from photons. There is also radio frequency EMR coming off the video processor chip that cross-talks into the micro-circuitry. Advances in semiconductor technology are ongoing to continue working this problem down.
Hi Nico, thanks for this video, I've seen it multiple times and your results are amazing! .. this weekend I tried 512 pics, but I wonder if you have an article or tutorial of how you bring all those beautiful colors. thanks,
Hi Luis, Many factors can affect color, the top factors are probably: 1. processing 2. darkness of the sky (less light pollution is better) 3. I was using a 'modified' camera that lets more deep red pass to the sensor. Check out the 'start to finish' tutorials on my channel (Andromeda, Orion, Lagoon) that go into more of the details including the processing. Let me know if you have any additional questions. Clear skies, Nico
Interesting video on a topic I never heard of before, is it possible to automate the process with a script to have one picture for each step? Then you could add them to a stop motion film where the progress might be visible even better.
Watched this 3 times right through. Good to see the examples too. I have some questions at iso 6400 f1.2, 2 sec exposures, with the total integration of 1024 images stacked that’s 34 minutes integration time with your example, Can you get the same results with the same signal to noise if exposures are longer for each image say 8 sec f2.5 6400 and 256 images that’s 34 minutes ? Or does the total integration time now need to be 128min (2 hours) with 1024 images ? To get the same result as you had ? Also can I shot at a lower ISO say 1600 8 sec exposures at f1.2 and take 256 images - total exposure time of 34 mins and still get the same signal to noise as your example? Sorry for long questions.
To do that, you would need to add a star tracker to avoid trailed stars. With equal total integration, the signal to noise is better with longer sub-exposures, but for reasons I did not go into in this video. This video was only about signal to noise ratio as it relates to 'photon noise' aka 'shot noise'. However there are noise sources associated with the camera itself. Some of those noise sources (chiefly readout noise) become much less of a problem if you take longer sub-exposures. There is a limit to this of course, but you can see modest gains up to about 5-10 minutes per sub-exposure. The ISO isn't a huge issue, but we are generally trying to find a sweet spot there balancing readout noise and dynamic range. The lower ISOs have larger dynamic range due to a larger full well, but higher readout noise. ISO 1600, 3200, or 6400 are safe bets on most modern camera bodies.
@@NebulaPhotos thanks for the info, I have a tracker but no guider and want to shot at 2-3 minutes at 400mm on a skyguidet pro, I hope that’s gonna be possible because up until now I have been doing 45sec - 1min subs. Love your videos very informative and keep up the good work.
Yes, everything in this video was calibrated with bias, darks, and flats. I didn't go into it since this video was my attempt to make a video all about stacking, so I didn't want to get sidetracked by other kinds of noise: thermal, fixed pattern noise, etc.
@@NebulaPhotos sweet! I was curious because if it turned out this good without it I was about to cut out a bunch of work for my unguided stuff lol thanks for the response!
things I learned from this: 1.how low f ratio optic can be less time consuming. 2. Nico is omega patient about his videos and spends big efforts for teaching stuff even when you do not get to learn new thing you can show people the easy explanation. 3. you do not need to have big ass optic to see the pictures sometimes wide angle is better than smaller fow not only showing more things on your photo but also for better photo composition.
2:29 Camera Set up
3:29 *1 image*
4:01 Crush the black with Curve adj
4:41 Minimal anatomy of Orion neb to start
6:39 Defn. of Noise, then 9:57 S/N ratio
7:18 Beneficial effect of "Mean" in stacking
8:26 The merit of Mean, explanation
6:47 *16 image group* > 11:37
9:57 Signal to Noise ration
10:17 Why S/N ratio improves with Stacking - Proportion
11:58 Horsehead neb in 16 image
12:19 Running man neb in 16 image
13:09 Witchhead neb in 16 images - Not yet visible
13:44 Recentering - 64 image group
14:24 Software to Recenter/align moving object images automatically
15:19 RAW file Liniar to gamma correction stretch/curve
17:24 *16 to 64* stack comparison
18:47 Flame & Horsehead neb details
19:41 Orion neb
20:13 Witchhead now showing up in 64 group
20:43 64 compare to 264 - 21:31
20:54 Angelfish nebula next to Betelgeuse
21:05 Barnard's Loop (catalogue designation Sh 2-276)
22:18 Dim object improvement - Witchhead
22:57 *256 to 1024* Total Integration of 34 minutes
24:08 Improvements in dust neb features
24:43 Boogeyman nebula
25:07 M78 reflection
25:35 Flame/Horsehead
25:51 Orion neb
26:36 Witchhead
25:56 *Comparison of all groupings*
28:08 Boogeyman neb
28:50 Barnard's loop
29:49 M78
30:35 Flame neb
31:32 Horsehead neb
31:53 Runningman neb
32:47 Orion neb (Messier 42, M42, or NGC 1976)
34:08 Where More can help
34:38 Star halo around Rigel, improvement with integration
35:08 Witchhead's chin, nose, and eye
35:59 Moral of the story
Props to you my man, thanks!
The effort that went into tgis
GOAT 🐐
yeah but not how to do it
Extremely well done. I've been stacking for a while but seeing a really thorough comparison is fantastic.
I once shot 1500 images of the Leo triplet and then realised they were all jpeg.....
OUCH!!!!!! I can feel ya Buddy, I've also been there.........
I cringed reading that. That's tough my man :(
Pain
What's even more stupid is that i went ahead and stacked it AND THE GALAXIES WERE REASONABLY RESOLVED -COMPLETELY UNTRACKED FROM BORTLE 9 😑. If it was RAW......
RIP bro
This is the clearest explanation of stacking I've seen on TH-cam. I've watched a few of your videos before, but after this one, I'm a subscriber. Thanks for clarifying.
Cheers Scott! Glad it hit the mark. Clear skies, Nico
That single 2s exposure image is actually mind blowing 🤯
That's what 3k$ lens and 3k$ camera gets you 😅
@@115justus actually a basic 500 dslr and 700 lens and a dark sky is all you need.
@@115justus No. You don't need the latest and greatest gear to take amazing images, you just need to know what you're doing. Sure, if you handhold your phone up at the sky, don't expect any amazing results, but that's not what phones were designed for anyway. But a cheap second hand camera like a Sony a6000 and a fast lens (something affordable, like a Sigma f/1.4 prime, 16, 30 or 50 mm) can achieve amazing results - if you know what you're doing.
@@115justus $6K is not needed. A total of $1k using a dedicated astro camera and astro telescope would get you even better results. But skills is also required.
@@astroscrolls5740 well, that lens is actually sold for 3000$
This is the best explanation of stacking and, more specifically signal to noise ratio I've seen on YT.
Gained a subscriber!
Glad you liked it! Thanks Charles!
Same here Charles
@@NebulaPhotos I have a question, is stacked 1024 photos(integration of 34 min) yield same result as 1 34min long exposure(assume it's possible with tracker and not considering the hot pixels)? I guess what I want to know is in general, is it better to stack more photos with shorter exposures or to stack less photos with longer exposures with same integrated time? Or do they have the same result? Thank you!
@@leezheng8161 Generally fewer photos with longer exposures is better than many shorter exposures. I explored this idea in this video: th-cam.com/video/mYucAuUrdTs/w-d-xo.html
@@NebulaPhotos oh great thank you! I will check it out. Btw, I am from Boston area too. I often shoot at Nubble, Cape Cod and White Mountains. Hope will bump into you one day haha.
Best description of signal to noise ration I've ever heard. Thanks for making it so clear.
Whenever someone asks me how image stacking works, I send them a link to this video. Really well explained, Nico!
The best explanation about stacking so far. Now it's crystal clear to me. Congrats. Excelent job there!
Thanks!
A great in-depth explanation of stacking and integration. Thanks Nico! Clear skies all!!
This is Definitely the best video yet on your channel .I am sure it is gonna be more popular than your Andromeda shot .Defining the meaning of astrophotography concept really made this video a lot better .
The deeper I get into astrophotography the more I appreciate the great job you do motivating newer amateur astrophotographers. Thank you very much!
I'm not a photographer, but I have so much respect for people who can capture the sky like this. Also, can we give a shout out to those amazing programmers who have designed software like this?
Without doubt, the most precise breakdown for this topic I've seen to date. VERY well done!
Nico, a brilliantly simple way to express a very complex astrophotography process... thank you so much for your endless effort!!!
Love the framing where you can explore so many different structures!
I’m a photographer interested in dipping my toes into Astro. I’m learning so much about both Astro and regular digital. Thanks!!
What a quality work! Bravo! The explanation of signal to noise was enlightening. I've done signal processing since grad school but for some reason, the simplicity of the explanation felt like "eye opening" although I know this stuff close to heart.
Nico, thank you for this excellent video! It has pushed me over the top to support you on Patreon at the highest (Seagull Nebula) tier. I started exploring astrophotography just over a year ago, and your videos have provided a helpful guide along the way. Comparison videos like this finally provide the means to understand why astrophotography imaging and processing practices are what they are. They help me understand how to improve within the limitations of my environment, equipment, and software -- and what additions/upgrades to consider. A similar comparison of various exposure lengths to achieve the same total integration would be nice, as would a comparison of the same targets using a dedicated and a non-dedicated (Ha-filtered) camera with all other parameters the same. Keep up the great work!
Thanks Dan! And thanks for the ideas for future comparisons. Good ideas. Cheers, Nico
I am totally new to astrophotography and you provided great explanations throughout the video. I appreciate it. Well done you've earned my subscription.
Great Video. Thanks Nico. While there are a lot of good videos on the net, it has been you and Trevor from astro backyard that have helped me the most. In a few months I have acquired a T3i and astro modified it myself. With a entry level tracking mount and my camera piggybacked on my scope, with a 55 to 250mm kit lens, I have gotten impressive images of The Pleiades, Flame, Horsehead, Running Man, and Orion Nebula, as well as a very detailed image of Andromeda Galaxy that is 1000 times better than I ever expected I could. Thank you very much. Your videos are an amazing tool for a beginner like me...
I JUST astromodified my T3i that's so exciting!
@Jim Lewandowski I think you will love it. I was amazed at how much more light it collected after the mod, especially in the IR end of the spectrum. It seems like it boosted UV a little bit as well as I got a little more detail on the Pleiades Nebulae after the mod with the same exposure times. I also use a IR/UV cut filter with a custom white balance and take decent wildlife shots with it. Just a great camera for the price. My next camera will be a 60D which is very affordable used and just as easy to modify. Should be even better...
That's great, keep at it. Try and visit a Bortle-1 location for some imaging and keep up that passion 👍
Which tracker do you use?
@@lepetitbaigneur9073, I use the Explorer Scientific iEXOS-100-2. It is a great little mount for the money (paid $499). Can track up to 90 second exposures with a quick alignment using the sight tube. Still haven't gotten a polar scope, but that should make it even better...
Amazing! Thanks for this. I've been meaning to use my DSLR with my telescope for quite a while now and do some image stacking.
Great video Nico, I just love your enthusiasm for the subject and that really comes across in your presentations. I am only one month into my astrophotography journey and my first object was Orion. With your videos and those from AstroBackyard, I really have found loads of tips and tricks. I did find your explaination of signal/noise ratio in this video very informative. I have a SWSA, a Canon EOS 60D and a Samyang 135mm lens (all purchased just for this hobby), but what I really need is some cloudless nights (in my current bortle 9 location).
Thank you so very much This is the first tutorial on image stacking to explain why I can't just copy and paste the images 1024 times.
That's AI you're describing 😂
Nice comparison and a good illustration of what’s possible with basic gear. You didn’t really talk about your f/1.2 lens but that makes a huge difference compared to the more common f/2.8 or f/4 lenses since you’re getting a lot more light to the sensor. Someone with a slower lens would need to increase the number of frames by a factor of four or eight to achieve comparable results.
Good point. And even for fast lenses you may need to stop them down to f/2 or f/2.8 depending on the lens quality. My Samyang (Rokinon) 135mm f/2 is producing strange starshapes on the edges on f/2 so I usually stop down to f/2.8.
Another thing to note is that he's using a camera that is factory "modded" to let through more light of certain wavelengths which is super useful for astro photography. A regular camera will not be as sensitive.
Does that mean we need more total exposure time with an f4 lens ? Or is total exposure time the same regardless of what settings are applied ?(eg; 1 hour total exposure is more than sufficient)?
@@Photographersforyou Yes, you'd need more total exposure time. I'd even argue that it doesn't scale linearly, as slower lenses give a worse S/N ratio for the same individual (per-frame) exposure time, making it harder to separate the two during processing.
@@tosvus This was the question I had after I watched the video. I tried to shoot Bernard's loop last night with a 50mm 1.8 and did around 10 minutes of exposure, but I couldn't see ANY of the loop or darker nebulae even after stacking and aggressive processing. I was using a stock Canon T7 though, so I figured that was the reason.
Thank you for making the concepts and process easily digestible. I'm new to this hobby, and had some very general understanding of "stuff", but this video helped it all to become clearer and more understandable.
Insanely well explained. Didn’t even know I wanted to know this but just found out a lot more about my cameras, even if you talked about Nebula photography. Makes me want to find a dark sky somewhere. New sub!
Have to say that even tho I have been imaging through a telescope with an equatorial mount for a good while, I still really like these "entry level" videos that you make. You have a great way of explaining the concepts and your videos are just a pleasure to watch.
Well done Nico. I got 'sucked in' to watching it because it was so good, especially the your individual pixel - signal to noise ratio explanations in the beginning. I wish you would have made this video five years ago. Cheers Kurt
Thanks Kurt!
Overall a great tutorial to introduce someone to Astrophotography! Usually like shorter tutorials, but the 40 minutes here were well worth it!
Worth mentioning too: The noise suppressed is also that of the camera sensor.
Isn't that noise caused by stuff like background radiation?
@@MFKitten no camera noise is mostly caused by the electric current of the camera sensor (for normal consumer cameras)
@@ssfalk41 its called by both random radiation and camera operation .
High ISO settings overheat the sensor and cause the noise
@@Cozfx Sorry that's just a myth.
ISO is like a VU meter indicating the volume of an audio amplifier. If you have to turn up the Volume control to where VU meter needle is pointing in the red area to be able to hear, it means the audio input from the preamp is too low. Similarly if you must use HIGH ISO it means your settings of Aperture and Shutter speed are wrong or you have not added more light (like using a flash).
If you plug in a mic to line-in, the signal to the power amplifier will be too low. Cranking up the amplifier power will only increase distortion due to low signal to noise ratio.
The Lens and Shutter speed settings are like setting the LIGHT preamp to the sensor. Wrong settings of Aperture and Shutter speed created the noise. NOT HIGH ISO.
Thank you so much for making videos, I don't know what I would do without these in depth videos explaining what everything is for and what it dose for using DSS.
I'm a newbie to astrophotography this video has really helped me to understand the importance of stacking and the usefulness of shorter exposures. I'm excited to try it myself
Hey, thanks. I was really interested in learning more about this. I first hear about this strategy seeing an awesome shot in a gallery and had no idea what it meant!!
Thanks Nico! Really made sense. Would love to see a video on how to bring out HDR details (eg with the Orion Nebula in your image).
WOW....Nico congratulations to you for creating on of the best, best video on this topic ever! wonderfully done. Thank you so much for sharing.
Thanks Shaleen! Glad you liked it!
Love how detailed your Videos are😊
I been searching for tutorials, but most of them are just showing me how to do it and was never defined tis clear on how it works.
This video explained everything I need to learn.
Thank you!!!
well done, such a stunning video! i was not thinking to take such photos before, but after seening your video i´m super excited to try it out too, thank you Nico!
One of the best video about stacking, very clear, expecially in the SNR explaination. Thank you so much.
Dude this is so so soooo helpful! You’re a legend for explaining it in such a simple way 👌🏻👌🏻👌🏻
Your 1 week long videos are never boring! Thanks for your effort. Cheers!
Really great video and very well explained!
I really enjoy practical experiments like this to demonstrate the theory. Well done.
So welldone Nico. I did once last year with my fuji xt3 + tripod + nikkor 80-200 f/4 ais. I stacked 900 photos in 3200 iso + 0,7" ss + f/4.0 + 200mm. It spent about 25 hours for stacking each time i stacked. I used both Sequator and Deepskystacker but i prefered sequator result. Final photo was pretty good but your really surprise me.
A video on his other factors affect that signal to noise ratio would be cool - like taking a one minute tracked exposure vs 30 two second exposures .. or different ISO comparisons etc
I can answer that rn. If your read noise is high you will never have the same quality, ever. In high LP its not that bog a deal but in low LP it takes a lot more time to swamp out the readnoise with data so longer exposures are far superiour.
Different iso? Iso will affect read noise at cost of dynamic range, so its basically a balance, with 2s exposures high iso is benefitial
Nico this is such an awesome instructional. I love how you simplified the process of how photons work. Most people just know taking several subs and stacking works but not really how or why and what’s happening. All the visual astronomers who say all my images are photoshopped and faked need to see this. 😂
I gotta give it to you; I didn't understand stacking before watching this video, and I've always thought that astrophotographers actively colour and paint the photos. Thank you for showing us how much difference you can actually get by taking more photos and stacking them. I thoroughly appreciated this!
As far as i know this was the most well illustrated explanation. The youtuber "Catching Photons" also provides a really great explanation of this with all the theory, but your video has a great balance of theory and practice.
You're really bringing out my inner geek with these excellent videos, I personally love the science and aesthetics of astrophotography (my new hobby) going to order a star adventurer pro v.soon too. Just so friggin amazing to me when I see another galaxy and think what the hell it actually is, billions of suns and planets just there like a smudge on the lens almost. Far out!!
Iam working for 15 years full-time as a commercial photographer.....dude, you're killing it!!! Thank you so much
I would like to see a comparison between images of the same total integration time but where each image is comprised of a different number of frames if you haven't done that already. For example: compare 900*2 second exposures and 3*10 minute exposures if you have the equipment for that and see what the difference is.
I believe Galactic Hunter already did a similar experiment. Check it out!
Not quite that extreme, but I did compare 30 minutes total with 1 sec. vs. 30 sec. exposures here: th-cam.com/video/mYucAuUrdTs/w-d-xo.html
How does an image get 'brighter' when every sub exposure is the same(time)? I know you 'stack' them, but how are you getting additional data on a pixel if it has the same amount of light hitting it?
That is what this video was trying to answer, but let me try in different words. Stacking has a cumulative effect so instead of capturing the photons hitting that spot over just 2 seconds you are combining all the photons that hit in that spot over the total integration time. In the case of my stack of 1,024, all the photons in 34 minutes. Photons don't arrive at a steady rate, but instead randomly, we call this random accumulation 'shot noise.' By capturing more photons, we lower the proportion of noise in the final photo, so you have more signal and the signal to noise ratio is better.
@@NebulaPhotos So, the pixels that recieve photons are 'stacked' while unexposed pixels get clipped, sort of like masking them off of each layer?
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I didn't know that photons were random until I watched the rest of the video. I typed my question before I finished it. Thanks so much for replying and the very informative videos.
Thank you, been interested in getting into this hobby and this actually was really eye opening on just how people get such beautiful photos of space.
This was a great video! I never knew you could stack images like this to get this result!
This is phenomenal. Awesome, clear and easy to understand information. Awesome job!
Very educating video. Thanks Nico.
But I was wondering: you stacked 64 images, resulting in like 8 minutes of exposure.
Can we get the same result - with tracking of course - by exposing 8 minutes (same ISO etc.)?
And thus we could get your 1024 stacked result by stacking 16 of those?
Also: I really only like the 1024-stack result because of the spectacular details.
Yes, not only the same result, but a better result. I don't really delve into in this video, but there are some drawbacks to using such short exposures having to do with camera noise (readout noise). With longer tracked exposures, you avoid those drawbacks, and will have a slightly better stack with equal integration.
Well done. Nice and clear. Great explanation of what goes on in stacking and how it is accomplished. Thank you for this great video.
Thanks Bill! Glad you liked it
Super interesting. I have enjoyed astrophotography for a while now but I didn't know that nebulas could be seen to that degree without a star tracker. Thank you for the theory as well.
Nice. I knew much of this but watched till the end. Clear, informative, and entertaining!
Thanks for the time and effort you put into this for the benefit of us novices. Great work.
very well explained video! I don't study cosmos but I could be able to follow the video with no clue. Thanks for the content :)
This is absolutely amazing! Good work, and nice explanation.
By the way, there is another advantage of stacking: Compared to images taken using tracking, you're additionally averaging out differences in the CCD's pixels. Assumed one pixel (one CCD cell) has a slightly different sensitivity than its neighbor, this difference would add up when you track with the stars, because you would force the light of one small star hit always the same pixel. When you pick your frame quasi-randomly, this does not occur.
Unfortunately, the noise you record does not only come from too few photons, it's also generated in the image sensor itself, caused by temperature (that's why they do so many efforts to keep the JWST's camera at very VERY low temperature), so tracking can have advantages as well. But that could be a different video.
One way to get around that is perhaps to use lunar tracking to get a slight offset
Fantastic! Extremely well presented! This gives me hope that I can do deep sky photography with my uncontrolled 8" Dob.
Hi Nico, great videos. I guess what you're saying is when you aline and stack multiple exposures you doing the same thing as taking one exposure.for the same amount of time. Seems to me shooting the shy at night is the same as shooting a landscape during the day, somewhat, both are made up of different light "intensities"; suns or stars transmit brighter "light" then say what they call the dust reflects.Cameras have a unique ability to change the intensity or actually "force" of light; the longer you leave your lens open the brighter things become: (I shouldn't use the term "force" because then you have to get into how light, electromagnetic frequencies, are created, and I don't think the text books are going to explain that right). Forces, seismic, electromagnetic, ocean, etc are the one aspect of "nature" that are not studied yet, and I find that unfortunate because they might explain the vary creation of everything; except for our souls of course. Thanks for the great tips, and keep up the wonderful videos,
Hi Robert, Yes, you got it. One long exposure and a stack of many sub-exposures are not technically the same thing, but they are functionally equivalent. In both cases, it is about collecting more light.
Nico, great explanation again! I've just joined your patreon because what you do is 100% the best I've found. You've helped me massively, I actually gave up AP for a few years as I couldn't get the hang of it but thanks to your superb tutorials I'm right back into it again. My astronomy club at the school where I teach has loved them too. Do you work with FITS files much? We're using the Faulkes Telescope Project's North observatory in Hawai'i and the learning curve with processing them is not for the daunted!
I have to say this video was flawless!! I mean perfect, thank you so much 🤩🙏 You made 38 minutes feel like 10 👌 I will deffenitly try to shoot a nebula some night 🌌👍
Today it was time to watch this again 🤩😀👍
Another fantastic video Nico. So informative. Would you consider doing a Photoshop processing video to demonstrate how to achieve a SHO Hubble pallet with a OSC camera? I would like to learn how to do this. I use either my 2600 MC Pro or Canon RP with an L-Extreme filter. Thanks. Dr B from Manitoba, Canada
Something to note: stacking isn't somehow "cheating" compared to a true long exposure photo, because a digital camera takes long exposures by stacking internally anyway. So whether it's done inside of the camera or outside really doesn't make much of a difference. I think manual stacking makes more sense, because taking a lot of short-exposure photos and combining them is simpler than taking one long tracked exposure with a strong filter in front of the lens. Simpler and less error-prone
This tangly came up on my timeline. Happy it did. Good work!!
Nebula photos > Astro backyard
thnx youre tips helped me with astrophotography and even other landscape pictures using astro processing methods
One of the best explanations how and why we take a night photos in multiple photos and not long one exposure photo
Thank you 😊
Nico, excellent. Have you tried Blend If in your layer properties to avoid blowing out the core of the Orion Nebula and bright stars? On the Underlying layer alt click the white carat to split it and drag the left half to the left.
Nico, you are so awesome! I not only signed up for your site, also Helena's too (I left her and all and inspiring message). Hey, I am just starting out in astrophotography ... and the both of you are all I need to learn and grow. Well, more you than ever since we live in the same US of A! Your my mentor and I am your student. You explain everything nicely, like English we can understand. Looking forward to more videos. Keep up the great work! Richard, Ramona, California
Nico you are my fave astrophotographer! Love your content!
Very nice video. Now I just need to decide if I want to focus on using my canon 50mm lens and cropping or used my 75 -300 kit lens with way less crop. I'm thinking the 50mm will make much nicer looking stars.
Noise is not the random amount of photons hitting the sensor but the random noise each electronic part generates.
I like the deep comparison of the different number of stacked images you show. It is very interesting to see that. Great work!
Those kinds of noise (thermal noise, readout noise) are not covered in this video, but in deep sky imaging make up a smaller percentage of the total noise than shot noise (random photon accumulation). Shot noise is why we stack. Thermal noise noise only goes up with longer exposure, but we have a different strategy for that called dark frames, again not mentioned in this video, but you can watch my longer videos to hear about calibration and more details on the process. Cheers, Nico
@@NebulaPhotos You can always learn something new! Thanks man!
Found this formular describing the signal to noise ratio (SNR) that made things much clearer.
SNR = P Qe t / (P Qe t + Dt + Nr^2)^(1/2)
where P is the incident photon flux (photons/pixel/second), Q(e) represents the CCD quantum efficiency, t is the integration time (seconds), D is the dark current value (electrons/pixel/second), and N(r) represents read noise (electrons rms/pixel).
Never thought about that the contribution of P would be so big. I always thought that the other effects of Q, D, and N are much more dominant.
I've tried loads of different tutorials before and none have been helpful at all. Thanks for this easy to understand and follow explanation. Much appreciated!!
I appreciate that you do videos like this! Always well explained and thoughtfully presented.
I was on the edge of my seat every minute! Thank you. I'm going to add this to my plans.
Great explanation - you go into the details like no one else 👍
Well done Nico! Looking to see more 85mm magics from you.
Really great video!
Based on this method, what do you think about "lucky imaging" for deep sky objects?
Any chance that you make a video about this topic too?
Yes, it's interesting. I would like to try it if I get a big scope where the seeing really matters.
@6:11 there is a red star/pixel/thing on the upper right end corner that keeps moving frame by frame. It don't look like a plane.
This is the best astrophotography video I've ever seen on TH-cam. Seriously good job dude. Makes me excited to try it myself. Did you have it on a continuous self timer with a two second interval?
I used an external intervalometer, but if your camera can do continuous 2 second exposures, go for it!
i swear I was waiting for the Nebula / CuriosityStream sponsorship....
the photos look amazing mate.
You are really good at what you do, you earned my subscription
A lot of that background noise isn't even sky photons coming in to excite the pixel sensor as you mentioned at 6:18. Noise will enter the video data channel through other sources like the the tendency for electrons to jump through the bandgap spontaneously instead of by excitation from photons. There is also radio frequency EMR coming off the video processor chip that cross-talks into the micro-circuitry. Advances in semiconductor technology are ongoing to continue working this problem down.
So Well done Nico. Learnt A Lot from this Video. I took 300x2 second exposures on the Orion nebula up close. Now I would like Try More Expo.!!✊🏻
Hi Nico, thanks for this video, I've seen it multiple times and your results are amazing! .. this weekend I tried 512 pics, but I wonder if you have an article or tutorial of how you bring all those beautiful colors.
thanks,
Hi Luis, Many factors can affect color, the top factors are probably: 1. processing 2. darkness of the sky (less light pollution is better) 3. I was using a 'modified' camera that lets more deep red pass to the sensor.
Check out the 'start to finish' tutorials on my channel (Andromeda, Orion, Lagoon) that go into more of the details including the processing. Let me know if you have any additional questions. Clear skies, Nico
I really like how you broke down thus video and the process in general. Thank you I will try. Also subbed now.
I've been looking for a video exactly like this! Thanks a bunch! Great job!
Interesting video on a topic I never heard of before, is it possible to automate the process with a script to have one picture for each step? Then you could add them to a stop motion film where the progress might be visible even better.
Thanks! I probably could write such a script if I had some free time, but I don't know of any that already exist that do that
This is incredible! I am going to try this for sure
Finally a step by step explanation of the benefits of stacking.
Watched this 3 times right through. Good to see the examples too. I have some questions at iso 6400 f1.2, 2 sec exposures, with the total integration of 1024 images stacked that’s 34 minutes integration time with your example, Can you get the same results with the same signal to noise if exposures are longer for each image say 8 sec f2.5 6400 and 256 images that’s 34 minutes ? Or does the total integration time now need to be 128min (2 hours) with 1024 images ? To get the same result as you had ?
Also can I shot at a lower ISO say 1600 8 sec exposures at f1.2 and take 256 images - total exposure time of 34 mins and still get the same signal to noise as your example? Sorry for long questions.
To do that, you would need to add a star tracker to avoid trailed stars. With equal total integration, the signal to noise is better with longer sub-exposures, but for reasons I did not go into in this video. This video was only about signal to noise ratio as it relates to 'photon noise' aka 'shot noise'. However there are noise sources associated with the camera itself. Some of those noise sources (chiefly readout noise) become much less of a problem if you take longer sub-exposures. There is a limit to this of course, but you can see modest gains up to about 5-10 minutes per sub-exposure. The ISO isn't a huge issue, but we are generally trying to find a sweet spot there balancing readout noise and dynamic range. The lower ISOs have larger dynamic range due to a larger full well, but higher readout noise. ISO 1600, 3200, or 6400 are safe bets on most modern camera bodies.
@@NebulaPhotos thanks for the info, I have a tracker but no guider and want to shot at 2-3 minutes at 400mm on a skyguidet pro, I hope that’s gonna be possible because up until now I have been doing 45sec - 1min subs. Love your videos very informative and keep up the good work.
Were there calibration frames at all or just the subs straight from camera? Incredible video!
Yes, everything in this video was calibrated with bias, darks, and flats. I didn't go into it since this video was my attempt to make a video all about stacking, so I didn't want to get sidetracked by other kinds of noise: thermal, fixed pattern noise, etc.
@@NebulaPhotos sweet! I was curious because if it turned out this good without it I was about to cut out a bunch of work for my unguided stuff lol thanks for the response!
things I learned from this:
1.how low f ratio optic can be less time consuming.
2. Nico is omega patient about his videos and spends big efforts for teaching stuff even when you do not get to learn new thing you can show people the easy explanation.
3. you do not need to have big ass optic to see the pictures sometimes wide angle is better than smaller fow not only showing more things on your photo but also for better photo composition.
Excellent video, thanks for helping us novices out with your info!
This is a magnificent walkthrough