My first attempt at astrophotography with only a DSLR

[Charming Potato]

Hello. It was my first time imaging the sky. I tried to capture M101 and sort of got it (very very faint). I only have a DSLR (Nikon z50) with kit lens (50-250Mm F/4.5-6.3) and no mount, only a generic tripod.

I took the data from my backyard in a Bortle 7-8 area inside the city. My lens was set to 100mm with F5 aperture and 1600ISO. I took 600 light frames @2 second exposure, 100 dark frames, about 40 flat frames and around 60 bias frames, and stacked them in DSS, then stretched in Gimp.

I know it is not the best result compared to what I see here, but is there anything I could have done to make it more clearer with my current setup?

Edited June 5, 2023 by Charming Potato

[Elp]

Galaxies in general require long exposure, the only one I managed in short exposures was Andromeda. M101 has quite low surface brightness as it's face on so it's light is spread out over an area so this also makes it more difficult. Think this one will require a tracker.

[carastro]

M101 is very faint, and 2secs won't cut it, especially from a Bortle 7 - 8 location.  You might be able to get some of the brighter targets but tracking, guiding and long exposure is really needed for DSOs.    

The good news is that your stars are nicely in focus, and you have done the right thing with calibration (especially flats) and lots of subs.  

A but of post processing would bring it out a bit more:

Edited June 5, 2023 by carastro

[Charming Potato]

Unfortunately Andromeda is not visible from my backyard until very late night due to houses in the way. This seemed like an easy target as this was straight up above. Is there anything else you'd reckon be an easy target for me? I have the following targets I can see in Stellarium that are straight up or close to straight up these days: 

North America Nebula, Messier 5, Herculeas Globular Cluster, M94 galaxy are amoung the few. Maybe if there is something else you know that is an easy target? I live in Germany so there is no Orion here these days, which I believe is the easiest target? 

 

[Charming Potato]

12 minutes ago, carastro said:

M101 is very faint, and 2secs won't cut it, especially from a Bortle 7 - 8 location.  You might be able to get some of the brighter targets but tracking, guiding and long exposure is really needed for DSOs.    

The good news is that your stars are nicely in focus, and you have done the right thing with calibration (especially flats) and lots of subs.  

A but of post processing would bring it out a bit more:

Wow. May I ask what did you use to bring these colors out? I'm new to post processing and photo editing in general, so I just followed a YouTube video that showed how to post process galaxy a little bit. What exactly did you change/add to make it like that? 

[carastro]

North America Nebula (this will be a better FOV for your camera), Hercules Globular Cluster (This will be small but doable), Andromeda galaxy when it is up.  Butterfly nebula  IC1319in Cygnus.  The Crescent in Cygnus (NGC6888), NGC6914 if you camera is modified for Astro,  Veil nebula complex maybe, Elephant's trunk nebula IC1396. 

But 2 secs is going to be pushing it for anything. 

Carole 

 

Edited June 5, 2023 by carastro

[carastro]

7 minutes ago, Charming Potato said:

Wow. May I ask what did you use to bring these colors out? I'm new to post processing and photo editing in general, so I just followed a YouTube video that showed how to post process galaxy a little bit. What exactly did you change/add to make it like that? 

Photoshop, levels and curves, and a bit of gradient exterminator (Plugin).  Balance colours.

Carole 

Edited June 5, 2023 by carastro

[Charming Potato]

9 minutes ago, carastro said:

North America Nebula (this will be a better FOV for your camera), Hercules Globular Cluster (This will be small but doable), Andromeda galaxy when it is up.  Butterfly nebula  IC1319in Cygnus.  The Crescent in Cygnus (NGC6888), NGC6914 if you camera is modified for Astro,  Veil nebula complex maybe, Elephant's trunk nebula IC1396. 

But 2 secs is going to be pushing it for anything. 

Carole 

 

Is it better to use the entire 250mm of zoom on the lens and have higher aperture of 6-6.5 or around 70mm with 4.5? Also I had read in one blog that for untracked photography, it is better to go with higher ISOs compared to lower as it is usually recommended? I believe I can increase my exposure time to 3 or 4 seconds if I play arihnd with the lens. How big of an impact would it be going from 2 to 3-4 seconds? 

[Elp]

Most of the interesting targets you have to wait until Sept through to winter (northern), and longer nights you'll have no issues getting Andromeda and Orion. At the time being try closed and open clusters which are essentially just stars so will pick up okay.

Iso depends on the camera, it doesn't really do much but increase noise levels the higher up you go.

Regarding time, just try it, you'll see if the stars start to trail quite easily.

Your main issue is:

A. Short exposure decreases the probability of a photon being registered on a pixel (creating the pixel signal response), by exposing longer you increase this photon collection and hence signal. Some DSLRs even have noise algorithms which remove faint signal from the photo when saving (Sony are notorious for this). Your short exposure is also fighting atmospheric seeing, if it's high moisture or temperature the view will be wobbling (like how you see the background shimmer just above hot road surfaces), long exposure will kind of average this seeing out per exposure.

B. DSLRs also tend to have a low quantum efficiency response compared to astro cameras, they also have blocking filters on top of the sensor lowering your ability to capture faint signal, it's why many people with DSLRs use modded ones though this only really helps with emission nebulae.

To capture the faint stuff you really do need tracking, if budget is an issue at the moment you can try diy-ing a barn door tracker, or one of the cheapest ones which work at shortish focal lengths is an Omegon LX.

Edited June 5, 2023 by Elp

[carastro]

Even a star adventurer or ioptron Sky Tracker will give you around 2 -3 mins with a camera lens.  

Edited June 5, 2023 by carastro

[wesdon1]

5 hours ago, Charming Potato said:

Hello. It was my first time imaging the sky. I tried to capture M101 and sort of got it (very very faint). I only have a DSLR (Nikon z50) with kit lens (50-250Mm F/4.5-6.3) and no mount, only a generic tripod.

I took the data from my backyard in a Bortle 7-8 area inside the city. My lens was set to 100mm with F5 aperture and 1600ISO. I took 600 light frames @2 second exposure, 100 dark frames, about 40 flat frames and around 60 bias frames, and stacked them in DSS, then stretched in Gimp.

I know it is not the best result compared to what I see here, but is there anything I could have done to make it more clearer with my current setup?

@Charming Potato Hi there. My friend, I am only 8 months into astrophotography, after years of visual astronomy. One thing thing I have learned during my first "Galaxy Season" ( They call the spring months Galaxy Season because Galaxies are mostly all we can see during this period ) is that Galaxies, and especially face on, faint ones like the one you imaged ( M101 ) are notoriously difficult to image. You need a good few hours sub exposures/integration, and also the processing side is very complicated when you're just starting out. All that said, I am very impressed with what you achieved with such basic equipment, and tiny total imaging/integration time! You should be proud! 

My best advice would be, if you can afford it, get a equatorial mount or a star tracker, and start going for the brightest DSO's, hone/learn your processing skills, and above all else keep it fun! ( I learned the hard way about "keeping it fun". I got too obsessed with wanting Hubble like astro images after just 5 minutes of doing astrophotography! LOL It made me miserable! LOL )

Best of luck Mr Charming Potato, and clear skies! 

Wes, Liverpool, UK ( Bortle 7 )

[Franklin]

Great image👍 and you got the Superdoopernova!

 

[wesdon1]

4 hours ago, Charming Potato said:

Unfortunately Andromeda is not visible from my backyard until very late night due to houses in the way. This seemed like an easy target as this was straight up above. Is there anything else you'd reckon be an easy target for me? I have the following targets I can see in Stellarium that are straight up or close to straight up these days: 

North America Nebula, Messier 5, Herculeas Globular Cluster, M94 galaxy are amoung the few. Maybe if there is something else you know that is an easy target? I live in Germany so there is no Orion here these days, which I believe is the easiest target? 

 

Maybe try a widefield shot of the night sky? They're very doable with just a tripod and dslr camera. Have you heard of the "500 rule"? Basically, it goes like this...

Divide 500 by the focal length of your camera lens, and the answer you get is roughly how long you can image night sky with just a stationary tripod, without suffering star trails in your images. So for example, I have a 55mm Canon lens, and want to image with it, so I divide 500 by 55, and get 9.09, rounded off to 9. So that means I can image night sky for roughly 9 seconds before I suffer star trails. So you could get, say, 50 x 9 second exposures of night sky, and stack them all in Deep Sky Stacker. Personally, I always knock 1 or 2 seconds off the answer, just to be sure I get nice apparently round stars. 

You could use this easy technique for a while to get some experience in astrophotography, and go from there.

Hope this helps! 

Wes

Edited June 5, 2023 by wesdon1
missed a bit

[Charming Potato]

On 05/06/2023 at 15:01, Elp said:

Most of the interesting targets you have to wait until Sept through to winter (northern), and longer nights you'll have no issues getting Andromeda and Orion. At the time being try closed and open clusters which are essentially just stars so will pick up okay.

Iso depends on the camera, it doesn't really do much but increase noise levels the higher up you go.

Regarding time, just try it, you'll see if the stars start to trail quite easily.

Your main issue is:

A. Short exposure decreases the probability of a photon being registered on a pixel (creating the pixel signal response), by exposing longer you increase this photon collection and hence signal. Some DSLRs even have noise algorithms which remove faint signal from the photo when saving (Sony are notorious for this). Your short exposure is also fighting atmospheric seeing, if it's high moisture or temperature the view will be wobbling (like how you see the background shimmer just above hot road surfaces), long exposure will kind of average this seeing out per exposure.

B. DSLRs also tend to have a low quantum efficiency response compared to astro cameras, they also have blocking filters on top of the sensor lowering your ability to capture faint signal, it's why many people with DSLRs use modded ones though this only really helps with emission nebulae.

To capture the faint stuff you really do need tracking, if budget is an issue at the moment you can try diy-ing a barn door tracker, or one of the cheapest ones which work at shortish focal lengths is an Omegon LX.

I am trying to look into used EQ mounts, but I haven't been able to find anything used so far for a good price (or something good in my range). I want to get something that will last me a good while as I want to get some sort of telescope or lens designed for astrophotography later on, so maybe something that can handle a good amount of weight? I've been trying to look for a EQ5 mount as you suggested in my other post earlier this week.

 

22 hours ago, wesdon1 said:

Maybe try a widefield shot of the night sky? They're very doable with just a tripod and dslr camera. Have you heard of the "500 rule"? Basically, it goes like this...

Divide 500 by the focal length of your camera lens, and the answer you get is roughly how long you can image night sky with just a stationary tripod, without suffering star trails in your images. So for example, I have a 55mm Canon lens, and want to image with it, so I divide 500 by 55, and get 9.09, rounded off to 9. So that means I can image night sky for roughly 9 seconds before I suffer star trails. So you could get, say, 50 x 9 second exposures of night sky, and stack them all in Deep Sky Stacker. Personally, I always knock 1 or 2 seconds off the answer, just to be sure I get nice apparently round stars. 

You could use this easy technique for a while to get some experience in astrophotography, and go from there.

Hope this helps! 

Wes

So I used the NPF rule for calculating this; one online and one in Photopills app. And both of them gave me exposure time of about 2-2.5 according to 100mm lens and that is what I rounded down to 2. I do have another lens which is 15-50mm @ 3.5-6.3 aperture, and this lens' lowest focal point is at 50mm at 4.5 aperture. I'll try both of them next time and see how it goes. Thank you for the suggestion!

 

I have also did the post processing again for the image, did I do it too much this time? I have played around with levels and curves, and added a little bit of saturation.

[jjohnson3803]

That's a pretty darn good image for your first attempt.  I think you should be proud of your accomplishment.

[Charming Potato]

38 minutes ago, jjohnson3803 said:

That's a pretty darn good image for your first attempt.  I think you should be proud of your accomplishment.

Thank you! I'm very happy with the results! 🙈

[Elp]

1 hour ago, Charming Potato said:

haven't been able to find anything used so far for a good price

Astrobuysell UK has a handful of skywatcher and ioptron mounts listed. A good seller will be able to speak with a passion about their equipment, what issues they've had, how they've tried to overcome it. Buy the seller as they say.

Edited June 6, 2023 by Elp

[tomato]

Great result for a first DSO image! As other posters have said the Andromeda Galaxy will be high in the sky in the Autumn with a darker sky and will give you a more pleasing result with the same kit. There will also  be some bright nebulae and star clusters through the winter that will be easier targets than M101. 
Keep looking for a tracking mount, that will be a big step forward for DSO imaging with your existing set up.

[Paul M]

It's a great start. There is much to like about that image. Nice sharp stars, good colour, you got your target plus the bonus prize of a S/N, the background is natural...

Bigger and brighter targets will respond to your "lucky imaging" approach much better than M101, keep at it and hone your skills. And most importantly enjoy this phase of your imaging career! It isn't a contest and it's great that allcomers can share their efforts. 

Find your own niche, this might be it but as already noted by others, a basic tracking mount is almost essential for DSO imaging going forward.

I'm still posting junk, that's my niche! 🤣

Alyn Wallace has done some stunning images with a DSLR and tracking mount: https://www.youtube.com/@AlynWallace

Peter Zelinka has put a lot of time into his tracking mount guides and how his imaging progressed in recent years: 

 

[Charming Potato]

21 hours ago, Paul M said:

It's a great start. There is much to like about that image. Nice sharp stars, good colour, you got your target plus the bonus prize of a S/N, the background is natural...

Bigger and brighter targets will respond to your "lucky imaging" approach much better than M101, keep at it and hone your skills. And most importantly enjoy this phase of your imaging career! It isn't a contest and it's great that allcomers can share their efforts. 

Find your own niche, this might be it but as already noted by others, a basic tracking mount is almost essential for DSO imaging going forward.

I'm still posting junk, that's my niche! 🤣

Alyn Wallace has done some stunning images with a DSLR and tracking mount: https://www.youtube.com/@AlynWallace

Peter Zelinka has put a lot of time into his tracking mount guides and how his imaging progressed in recent years: 

 

I have been looking into trackers, and I was able to identify difference between azimuth and EQ mounts. I'd rather just spend on an EQ mount than a star tracker so I don't have to worry about the mount for an unforeseeable future (I know nothing is future proof).

 

Speaking of which, I found this deal: https://www.astroshop.eu/equatorial-without-goto/omegon-mount-eq-500-x-set-with-tracking-motor-polar-finder/p,78169

Is this a good mount? It is in my budget, and I feel like it is much better priced for all the features it has. It even has a GoTo mechanism. Is it bad for me to use GoTo at this point?

[Franklin]

The above mount doesn't have Goto, it has a dual axis motor drive kit so you still have to locate targets. Also, it looks like a revamped EQ3/2 so the claimed 10kg payload is wishful thinking. An EQ5, Exos2, CG5 or GP would be a much better mount in the long run imo.

Sky-Watcher EQ3-2 Deluxe Astronomy Mount | First Light Optics

Edited June 7, 2023 by Franklin

[imakebeer]

@Charming Potato

I'm still new to AP only having started in Oct 2022 so feel free to take this with a large pinch of salt, but I have a slightly different view..... When I was starting out I asked for advice which you can read in this thread here.....

To sum up, I don't think you need longer individual light frames - what you need is longer TOTAL integration time, i.e. the TOTAL time the shutter is open, summed up over ALL your exposures (as well as light frames you'll also need to take a smaller number of dark, bias and flat frames, explained here http://deepskystacker.free.fr/english/faq.htm )

To a first approximation at least, and as far as I've understood it, whether you do 1 x 600s exposure or 600 x 1s exposures it doesn't really matter. Longer exposures save disk space, but it's 2023 not 1993 and storage is cheap. I do have a tracking mount now but so far I'm still only using 60s exposures.

A tracking mount is desirable, but no reason you shouldn't continue to work with the gear you already have and improve on your current (and not bad at all!) image while you consider upgrades. For one thing there's plenty you can learn about the post-processing side along the way. However, one thing a static mount won't deal with is field rotation, i.e. your target appears to rotate as it moves across the sky. To some degree your stacking software might be able to deal with this.

I started off with a Nikon D5500 + 18-300mm Nikkor zoom lens, all mounted on my wobbly 20 quid Amazon tripod, and using a manual remote shutter release. I think I was using a FL around 100-200mm, individual exposures up to about 5s long and ISO 1000. Since my tripod doesn't track I recall nudging it round every so often to keep my target centred in the view! I had another play along these lines just recently actually, wide angle at 18mm FL, ISO 400 and 15s exposures.

You can certainly use the 500 rule as a guide, but it is just a guide. You'll need to experiment in practice to figure out what exposure length you can get away with in practice for a given FL.

Once you've done that you can play around with the ISO to get the histogram in the right place - you want the peak around 1/4 to 1/3 of the way from the left hand end. As long as it's not bunched up all the way to the left (or right) then you should have enough wiggle room left when it comes to post-processing in GIMP. Remember higher ISO = more noise so lower ISO is better in this regard.

Something else useful is having something to control your camera to take all these multiple pictures. Your Nikon might have something built-in - mine does but it seems a bit hit and miss. An alternative is a programmable intervalometer remote shutter release, or a laptop running some software such as BackYard Nikon. At minimum you need someway to trigger the camera without touching it, otherwise it'll wobble.

For stacking, you mentioned DSS - I've never used it but it seems popular. Siril is also free and very powerful but as long as you have light, dark, bias and flat frames it's quite easy to use the pre-supplied script for stacking and then follow the tutorial and do some initial post-processing.

For further tweaking, you mentioned GIMP - I haven't needed to go much beyond this yet. I found this video very helpful to get me started:

 

 

[FunkyKoval35]

18 hours ago, imakebeer said:

To a first approximation at least, and as far as I've understood it, whether you do 1 x 600s exposure or 600 x 1s exposures it doesn't really matter. Longer exposures save disk space, but it's 2023 not 1993 and storage is cheap. I do have a tracking mount now but so far I'm still only using 60s exposures.

I disagree. There is a reason why companies are making tracking mounts for astrophotography, and peoples are buying them   10x30s image will be much noiser and will have much less detiails than 1x300s image.

Edited June 9, 2023 by FunkyKoval35

[carastro]

 

23 hours ago, imakebeer said:

@Charming Potato

To sum up, I don't think you need longer individual light frames - what you need is longer TOTAL integration time, i.e. the TOTAL time the shutter is open, summed up over ALL your exposures (as well as light frames you'll also need to take a smaller number of dark, bias and flat frames, explained here http://deepskystacker.free.fr/english/faq.htm )

To a first approximation at least, and as far as I've understood it, whether you do 1 x 600s exposure or 600 x 1s exposures it doesn't really matter. Longer exposures save disk space, but it's 2023 not 1993 and storage is cheap. I do have a tracking mount now but so far I'm still only using 60s exposures.

A tracking mount is desirable, but no reason you shouldn't continue to work with the gear you already have and improve on your current (and not bad at all!) image while you consider upgrades. For one thing there's plenty you can learn about the post-processing side along the way. However, one thing a static mount won't deal with is field rotation, i.e. your target appears to rotate as it moves across the sky. To some degree your stacking software might be able to deal with this.

 

I also disagree with the comment above:   You cannot get decent DSLR images with short exposures, getting lots of them will only give less noise, not increase the signal captured.   Maybe you can with CMOS but the OP is using a DSLR. 
 

GOTO will certainly make life easier for you.  But the main thing you need if you cannot afford a proper imaging mount is tracking in order to increase the exposure length.  This will still be limited without guiding but a big step forward from where you are now.    

Guiding would be even better but will add to the expense. 

Edited June 9, 2023 by carastro

[Charming Potato]

22 hours ago, imakebeer said:

@Charming Potato

I'm still new to AP only having started in Oct 2022 so feel free to take this with a large pinch of salt, but I have a slightly different view..... When I was starting out I asked for advice which you can read in this thread here.....

To sum up, I don't think you need longer individual light frames - what you need is longer TOTAL integration time, i.e. the TOTAL time the shutter is open, summed up over ALL your exposures (as well as light frames you'll also need to take a smaller number of dark, bias and flat frames, explained here http://deepskystacker.free.fr/english/faq.htm )

To a first approximation at least, and as far as I've understood it, whether you do 1 x 600s exposure or 600 x 1s exposures it doesn't really matter. Longer exposures save disk space, but it's 2023 not 1993 and storage is cheap. I do have a tracking mount now but so far I'm still only using 60s exposures.

A tracking mount is desirable, but no reason you shouldn't continue to work with the gear you already have and improve on your current (and not bad at all!) image while you consider upgrades. For one thing there's plenty you can learn about the post-processing side along the way. However, one thing a static mount won't deal with is field rotation, i.e. your target appears to rotate as it moves across the sky. To some degree your stacking software might be able to deal with this.

I started off with a Nikon D5500 + 18-300mm Nikkor zoom lens, all mounted on my wobbly 20 quid Amazon tripod, and using a manual remote shutter release. I think I was using a FL around 100-200mm, individual exposures up to about 5s long and ISO 1000. Since my tripod doesn't track I recall nudging it round every so often to keep my target centred in the view! I had another play along these lines just recently actually, wide angle at 18mm FL, ISO 400 and 15s exposures.

You can certainly use the 500 rule as a guide, but it is just a guide. You'll need to experiment in practice to figure out what exposure length you can get away with in practice for a given FL.

Once you've done that you can play around with the ISO to get the histogram in the right place - you want the peak around 1/4 to 1/3 of the way from the left hand end. As long as it's not bunched up all the way to the left (or right) then you should have enough wiggle room left when it comes to post-processing in GIMP. Remember higher ISO = more noise so lower ISO is better in this regard.

Something else useful is having something to control your camera to take all these multiple pictures. Your Nikon might have something built-in - mine does but it seems a bit hit and miss. An alternative is a programmable intervalometer remote shutter release, or a laptop running some software such as BackYard Nikon. At minimum you need someway to trigger the camera without touching it, otherwise it'll wobble.

For stacking, you mentioned DSS - I've never used it but it seems popular. Siril is also free and very powerful but as long as you have light, dark, bias and flat frames it's quite easy to use the pre-supplied script for stacking and then follow the tutorial and do some initial post-processing.

For further tweaking, you mentioned GIMP - I haven't needed to go much beyond this yet. I found this video very helpful to get me started:

 

 

Thank you for your input! The skies are clear tonight so I'm planning to go to a nearby park to get something easy to capture. Andromeda is in a really bad spot to catch, so I'll refrain from that, but I'll try a star cluster or a nebula. I'll play around with the settings as you mentioned. Z50 does have a built in intervalometer and that's what I used, as using an external one isn't as simple as plug and play for this camera.

I really want to have a mount, but being a student, no job and 2 terminally sick cats who have very high vet bills, I have decided not to go through with the mount for now. I'll keep doing what I can with what I have, and I really enjoyed doing it. Once I hit the limit of what I can do with this equipment, hopefully I'll have a job by then 😂. 

Thank you for the tip for choosing the ISO. I did not know that was possible (I'm not very familiar with my camera, or any sort of cameras). I'm planning to go out tonight as it seems like it will be a clear sky tonight. Hopefully I'll have good luck again 🤞.