SNR increases as the square root of integration time, so to double the SNR you have to quadruple the integration time. If OP wants an image that is roughly twice the depth, then he needs to take 4x the current amount of data.
Doubling the integration will result in a 1.41x SNR increase which is still easily noticeable especially when the current 2 hour dataset is still very short at least for fainter targets.
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TiffsAndAstro:
Szijártó Áron:
Hello and welcome I'd like to ask everyone experienced in this or knows how many frames we need to take to bring out most of the details from a deep sky object like those that are nebulas and are faint.
I'm been hunting for a faint deep sky object since the previous year, the Witch Head Nebula with my Seastar S50 telescope, however.
Even I collected 800 frames of data. I can't bring out every detail from this kind of nebula in siril.
Does anyone have experience in this or know how many frames or data we need to bring out all of the details of a nebula like this?
I just guessed that if we have 500 frames, that is the amount where you can bring out the most details of the deep sky object well mostly from a galaxy but not a nebula.
Can anyone tell?
Szijártó Áron:
Kevin Wilcox:
I got a very good image of the Witches Head nebula with just 3 hours of data. Unsure whether you’d get the same result with a Seestar.
Well, I now had 800 frames which was 2 hours. I merely managed to bring out only the outer interior or whatever you call it of the nebula.
So, how many frames did you collect under these hours? I right now have 1000 frames, although I might need to get more exposure time if I really can.
Targets like witch head are feint, relatively very feint. 2 hours just won't do it 
Moonlight will ruin it too.
I have beginnervgear, bortle6 and won't even attempt this. Even When new moon and no clouds I'm around Bortle 4 Rural Skies assuming or what you call it. Although, I have tried to photo grpagh it during the new moon, since that is the right phase for star gazing. You also can see the differences between the LP filter being used and no LP filter image. You get a very sharp image without the LP filter but if u use it it won't be the same but still visible. It's a good thing Seastar has an LP filter built in, so if a full moon is about to occur this would be the best to use during these days.
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Szijártó Áron:
I'm around Bortle 4 Rural Skies assuming or what you call it.
Although, I have tried to photo grpagh it during the new moon, since that is the right phase for star gazing.
You also can see the differences between the LP filter being used and no LP filter image. You get a very sharp image without the LP filter but if u use it it won't be the same but still visible. It's a good thing Seastar has an LP filter built in, so if a full moon is about to occur this would be the best to use during these days. As has already been stated, this is a very dim object. You should only photograph it during a new moon. The witch head is also a reflection nebula. The Seestar's light pollution filter should only be used with emission nebulae. You'll be doing nothing but hurting yourself photographing during the moon, or using the LP filter. Time is the only thing that is going to help you. You have two hours and your don't like the image. Go up to 4 hours and see if you like the image. If you don't, go up to 8 hours. If you don't like that well...give up and find a better object. You'll be stacking 2880 images at 10s a piece. Hope you have a huge hard drive.
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I don't know exactly what you're trying to bring out, nor all the specifics of your setup and acquisition etc..
With my rig (IMX571 mono, Askar 120mm f/7 APO) I like to consider 10h an acceptable minimum for a relatively dim target.. Take M78 for example, I would want AT LEAST 10h, probably 7h Lum and 1h each of R, G and B to show the outter dusty areas of the nebulae. That said, I would not for 1 second think that this is enough to get the absolute best out of the target, and to do that, I would likely double that to 14h L, 2h R, G and B, then also add ~10h of Ha as well for good measure..
Now your question of 'how many frames' really depends on a few things.
If you're running a modern CMOS camera that has very low read noise, then you might end up with LOTS of short subs, if you're running narrowband, you may end up with fewer, longer subs. However, if you're running an older CCD camera, you may well be running 20 minute sub expsosures as the read noise is FAR worse, so taking 3 subs per hour is better for your noise levels than shooting 20~60 subs an hour with 3~1 minute subs.
With my old KAF8300 ccd, I would shoot 10h as 30x1200s subs, and this would provide a very good overall result.
with my IMX294C and narrowband filters, I would shoot 10h as 120x300s subs and that would provide a very good, clean result.
With the IMX571 and LRGB, I would shoot 10h as 200x180s subs, and with narrowband, I might shoot 60x600s subs.
these would be my 'acceptable minimums' with these cameras to get a result where I could dig pretty deep into the data and get a lot of very faint detail out of the data without having to go absolutely insane fighting against the signal to noise ratio.
I guess the answer to your question is, 'it depends'…
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Furthermore, having read more of the post and replies… The witch head nebula is going to DEFINITELY require 6~10h, you should ONLY accumulate data when moon is less that 20%, and a minimum of 80° away from the target… I can't tell you what the noise characteristics of the Seestar are like, but I know its limited to short duration exposures, but the same rule applies… however many subs it takes for you to reach that 10h mark is going to be the requirement.
You will then probably want to integrate that data in batches of say 2h each, then integrate the 5 resulting images together, as running an integration on 10,000 images may be a little more work than your computer wants to do.
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I've just seen a seastar 20 hours on m51 and it's really fantastic. It's a very capable device, just don't use any filters and try and get at least 8 hours, as a guess? If you're a fellow beginner though, I'd suggest going after easier targets first  |
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Ethan Sweet:
Szijártó Áron:
I'm around Bortle 4 Rural Skies assuming or what you call it.
Although, I have tried to photo grpagh it during the new moon, since that is the right phase for star gazing.
You also can see the differences between the LP filter being used and no LP filter image. You get a very sharp image without the LP filter but if u use it it won't be the same but still visible. It's a good thing Seastar has an LP filter built in, so if a full moon is about to occur this would be the best to use during these days.
As has already been stated, this is a very dim object. You should only photograph it during a new moon.
The witch head is also a reflection nebula. The Seestar's light pollution filter should only be used with emission nebulae. You'll be doing nothing but hurting yourself photographing during the moon, or using the LP filter.
Time is the only thing that is going to help you. You have two hours and your don't like the image. Go up to 4 hours and see if you like the image. If you don't, go up to 8 hours. If you don't like that well...give up and find a better object. You'll be stacking 2880 images at 10s a piece. Hope you have a huge hard drive. Oh, I do have a pretty good hard drive. I only have the C drive which confused me a lot, cause I only used the D and C drives previously in my old PC laptop which was sadly ruined. But the captured objects I did were saved on the one drive. And now I have a powerful PC, it only takes under 5 minutes to stack an image. It's weird btw that the Seastar app designates almost every nebula with the LP filter. Maybe because those are emission ones it has the filter assigned.
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TiffsAndAstro:
I've just seen a seastar 20 hours on m51 and it's really fantastic.
It's a very capable device, just don't use any filters and try and get at least 8 hours, as a guess?
If you're a fellow beginner though, I'd suggest going after easier targets first  Since it happens to be a full moon again, I have a few questions and might need to seek confirmation in a new post. Which celestial objects are suitable for observation during this time, aside from nebulas? Can I focus on star clusters or other star-related objects? What about galaxies? I understand that galaxies can be quite faint, except for their cores, but I would like to clarify this. I'm primarily a beginner in this field; although I'm a regular photographer, astrophotography is only a partial interest of mine.
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That depends on a lot lot of factors so just try and see what your limits are. For me, anything past gibbus is too much light. Closer to full than that and my guiding starts to run into trouble with fainter guide stars being lost often. Full Moon is a time for testing or taking a night off, at least for my setup and conditions.
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Tony Carro:
Or shoot the moon lol, so right!
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TiffsAndAstro:
Szijártó Áron:
Hello and welcome I'd like to ask everyone experienced in this or knows how many frames we need to take to bring out most of the details from a deep sky object like those that are nebulas and are faint.
I'm been hunting for a faint deep sky object since the previous year, the Witch Head Nebula with my Seastar S50 telescope, however.
Even I collected 800 frames of data. I can't bring out every detail from this kind of nebula in siril.
Does anyone have experience in this or know how many frames or data we need to bring out all of the details of a nebula like this?
I just guessed that if we have 500 frames, that is the amount where you can bring out the most details of the deep sky object well mostly from a galaxy but not a nebula.
Can anyone tell?
Szijártó Áron:
Kevin Wilcox:
I got a very good image of the Witches Head nebula with just 3 hours of data. Unsure whether you’d get the same result with a Seestar.
Well, I now had 800 frames which was 2 hours. I merely managed to bring out only the outer interior or whatever you call it of the nebula.
So, how many frames did you collect under these hours? I right now have 1000 frames, although I might need to get more exposure time if I really can.
I had 36 x 300 second subs, using a ZWO ASI5333 MC and an Optolong L-extreme filter, Bortle 7 skies, no moon. Plus calibration frames |
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Szijártó Áron:
TiffsAndAstro:
I've just seen a seastar 20 hours on m51 and it's really fantastic.
It's a very capable device, just don't use any filters and try and get at least 8 hours, as a guess?
If you're a fellow beginner though, I'd suggest going after easier targets first
Since it happens to be a full moon again, I have a few questions and might need to seek confirmation in a new post. Which celestial objects are suitable for observation during this time, aside from nebulas? Can I focus on star clusters or other star-related objects? What about galaxies? I understand that galaxies can be quite faint, except for their cores, but I would like to clarify this. I'm primarily a beginner in this field; although I'm a regular photographer, astrophotography is only a partial interest of mine. Pick a brighter target from telescopius.net, if it’s full moon, you can either shoot the moon or pick something at least 90 degrees away from it and use the NB filter (only for nebulas). For galaxies, star clusters, dust and dark nebulas don’t use the filter! Right now there are plenty of options in and around Orion, Rosette, Cone, etc. On the other hand, this is a hobby, do something that’s fun for you!
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Szijártó Áron:
TiffsAndAstro:
I've just seen a seastar 20 hours on m51 and it's really fantastic.
It's a very capable device, just don't use any filters and try and get at least 8 hours, as a guess?
If you're a fellow beginner though, I'd suggest going after easier targets first
Since it happens to be a full moon again, I have a few questions and might need to seek confirmation in a new post. Which celestial objects are suitable for observation during this time, aside from nebulas? Can I focus on star clusters or other star-related objects? What about galaxies? I understand that galaxies can be quite faint, except for their cores, but I would like to clarify this. I'm primarily a beginner in this field; although I'm a regular photographer, astrophotography is only a partial interest of mine. Give some a try and see? As a beginner I image whenever weather allows just for practice. results under moonlight are usually not prize winning Maybe choose some of the brightest targets first like M42? I'm sure more experienced here will offer better advice
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I am rather new to this so take my answer with a grain of salt. However, I just watched this video from Peter Zelinka who covered this exact topic beautifully: https://www.youtube.com/watch?v=8DhRy1MT1Qs&t=1051s&pp=ygUkZiBzdG9wIGV4cG9zdXJlIGRhbWlhbiBwZXRlciB6ZWxpbmthThe TLDR: Generally, you will start getting good results between 4-8-16 hours on an objects. But these factors significantly affect your desired integration time: Common F-stops: F2.8 -> F4 -> F5.6 -> F8 -> F11 The light gathering ability doubles for each F-stop. So for example, an F8 telescope gathers twice as quickly as an F11 telescope. Your F-stop affects your desired integration time. Light pollution and the ability on certain objects to filter it out affects this. In light-polluted areas, you will have to work harder to counteract noise pollution. The brightness of your objects, and the level of detail you hope to bring out in the darker areas affects your desired integration time.
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Depends on your sky conditions, filters and target. Witch head and other reflection nebulae you need to be in dark sky and then you'll get a great image after 1-2 hours. For narrowband I fail to see any improvement after 4-8 hours in my conditions (B7). I usually measure SNR as I go and make a call on it but you can just be subjective. There's no point going forever if you see no benefit- there's diminishing returns and clear sky is too rare to 'waste'. Also invest in NXT (and BXT) as that is a good substitute for 2 or 3 times the data.
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if you want to impress your grandma, one frame will do. “Oh its lovely dear”.
If you want an IoTD, then a few more will be required.
It all depends on your audience which is really mostly yourself.
When I started out, I tried to get as many objects in one night as possible (so many DSOs, so little time) with a 200mm camera lens. And I was happy.
Nowadays I tend to do one object over one, two, three nights - and having spent an unconscionably large amount of cash, I can now choose my telescope to fit the faintness of the object. And now I am never happy.
Welcome to the hobby.
(Seriously, I do find that an SNR of around 40 per spatial resolution element gives a very pleasing picture)
CS Brian
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Szijártó Áron:
Hello and welcome I'd like to ask everyone experienced in this or knows how many frames we need to take to bring out most of the details from a deep sky object like those that are nebulas and are faint.
I'm been hunting for a faint deep sky object since the previous year, the Witch Head Nebula with my Seastar S50 telescope, however.
Even I collected 800 frames of data. I can't bring out every detail from this kind of nebula in siril.
Does anyone have experience in this or know how many frames or data we need to bring out all of the details of a nebula like this?
I just guessed that if we have 500 frames, that is the amount where you can bring out the most details of the deep sky object well mostly from a galaxy but not a nebula.
Can anyone tell? I also just got the Seestar S50! As many will have told you it is more about the total integration time rather than the number of pictures you stack. Because Seestar S50 can only take 10 second exposures, 800 pictures is actually only equal to 2.2 hours. To get twice as high quality pictures, you need to at least double you exposure time which means you are looking at closer to 1600 pictures. To double the light from there again, you are looking at 8 hrs. For that you will need 3200 subs. This is especially true because the Seestar S50 is abit inefficient with its given time: Because this smart telescope is not currently mounted in EQ config, many subs get discarded due to star trails. In my case, out of 60 minutes, I am maybe getting about 30 minutes of real integration time. This means that if you want 8 hours of subs, you may need 16 real hours. This means that you are probably looking at multiple nights of integration.
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