Starting to image DSO

[feverdreamer1]

Hi,

After several years in the photography world I decided to take a plunge into astrophotography, haven taken pictures of the moon, I now plan to capture DSO, unfortunately, I live in a bortle 6/7, and was planning to shoot orions nebula but found out it stays below the horizon for the summer. This is why I turn to the forum: are there any DSO that can be easily captured with a DSLR, a tripod and some software like sequator, and that is visible in  summer too? Ideally if it can be near the zenith it would be best, due to the annoying sodium light streets.

Also if you could post some images of DSO taken with a DSLR and a tripod ( and software of course)that would help me make an idea of what I should expect.

The camera I plan on using is an old canon eos 550d, without any modifications.

Thanks in advance,

S

[JoshHopk]

Hi there,

Because DSOs are very dim, you need to use long exposures to bring them out in images. You will be limited to very short exposures on a tripod, as it doesn’t track the constantly moving sky. This will cause your image to be blurred; at low focal lengths however this is not so apparent.

Something like the Sky-Watcher Star Adventurer would allow you to take much longer exposures.

With your current set up, and perhaps a light pollution filter, you may be able to do some wide field images of the Milky Way, but not much else. You can also download a planetarium software, such as Stelllarium, and this will show you what deep sky objects are visible and where they are located in the sky.

HTH, Josh  

[feverdreamer1]

Hi Josh and thanks for the fast reply,

I've seen trackers but they're really expensive 😅.

And after some online research I found that stacking many images might have the same result as a long exposure? I really dont know if this is true.

Thanks in advance,

S

[carastro]

Agree, you need a tracking platform to do DSO, an equatorial mount.  Low budget Sky-Watcher Star Adventurer as had already been suggested.  If you really want to go for it and buy a telescope, a Skywatcher HEQ5 minimum.

There are not many nebulae in the sky at the moment let alone near the Zenith, we are just coming out of what is called galaxy season.  However stuff in Cygnus will be suitable for your camera.  North America nebula.  Butterfly Nebula, but these all needs long exposure and several hours of data.

It is good that you understand your camera (presume it is an unmodified DSLR).  You find find that Astrophotography is quite a different kettle of fish to normal photography with different challenges, but understanding your camera will help for camera lens imaging.  Additionally with an unmodified camera you are cutting out the Ha spectrum, and most people get their DSLRs modified for astro work, or buy an already modified DSLR.

Here are some images I took with a DSLR in my early days of imaging back in 2011 ish, but this was with my modified DSLR .

M27 in Cygnus (just over an hour of data)

NGC6960 Western Veil Nebula in Cygnus 1 1/2 hours of data:

 

North America Nebula in Cygnus 3 hours 10mins.

  

HTH

Carole 

[carastro]

Quote

stacking many images might have the same result as a long exposure? I really dont know if this is true.

I think this only works with CMOS cameras, but don't ask me how.

I am afraid you will have little success without a tracking mount.  Stars will be trailed or not enough data.

Carole 

[feverdreamer1]

48 minutes ago, carastro said:

Agree, you need a tracking platform to do DSO, an equatorial mount.  Low budget Sky-Watcher Star Adventurer as had already been suggested.  If you really want to go for it and buy a telescope, a Skywatcher HEQ5 minimum.

There are not many nebulae in the sky at the moment let alone near the Zenith, we are just coming out of what is called galaxy season.  However stuff in Cygnus will be suitable for your camera.  North America nebula.  Butterfly Nebula, but these all needs long exposure and several hours of data.

It is good that you understand your camera (presume it is an unmodified DSLR).  You find find that Astrophotography is quite a different kettle of fish to normal photography with different challenges, but understanding your camera will help for camera lens imaging.  Additionally with an unmodified camera you are cutting out the Ha spectrum, and most people get their DSLRs modified for astro work, or buy an already modified DSLR.

Here are some images I took with a DSLR in my early days of imaging back in 2011 ish, but this was with my modified DSLR .

M27 in Cygnus (just over an hour of data)

NGC6960 Western Veil Nebula in Cygnus 1 1/2 hours of data:

 

North America Nebula in Cygnus 3 hours 10mins.

  

HTH

Carole 

Wow. The pictures are breathtaking but I guess you used a tracker. That's really a pity, was hoping to capture some DSO now that I'm free. Also you mention the milky way, and this may be a dumb question, but if I can't see the milky way with my eyes, can I get it from stacking multiple exposures? (Without a tracker).

And also you mention that with a modified DSLR I can't get Ha, but if I were to modify it:

1) Could I do it myself?

2)How much would it cost? (Tools, etc.)

3)I plan on using the DSLR for daylight photography too, so would this be altered with the modifications?

Thank you so much,

S

[MarkAR]

6 minutes ago, feverdreamer1 said:

1) Could I do it myself?

There are a few tutorials online, not for the faint hearted though.

7 minutes ago, feverdreamer1 said:

2)How much would it cost? (Tools, etc.)

There's a few companies that can do it for you, average price maybe £100.

8 minutes ago, feverdreamer1 said:

3)I plan on using the DSLR for daylight photography too, so would this be altered with the modifications?

You would need a clip in filter and probably have to play with the white balance.

 

9 minutes ago, feverdreamer1 said:

if I can't see the milky way with my eyes, can I get it from stacking multiple exposures?

Yes to some extent. If you stack untracked images you will have to crop quite a bit.

One method is to centre on a star, take an image or two of maybe 15 to 30 seconds, re-align on the star, take another shot or two and so on. That way you wont have to crop the edges so much.

[carastro]

Quote

The pictures are breathtaking but I guess you used a tracker.

Yes all long exposure not only with a tracking mount but guided too (guiding tweaks the tracking to keep it more accurate).

Nothing is cheap in Astrophotography unfortunately.

Carole 

[feverdreamer1]

2 hours ago, MarkAR said:

There are a few tutorials online, not for the faint hearted though.

There's a few companies that can do it for you, average price maybe £100.

You would need a clip in filter and probably have to play with the white balance.

 

Yes to some extent. If you stack untracked images you will have to crop quite a bit.

One method is to centre on a star, take an image or two of maybe 15 to 30 seconds, re-align on the star, take another shot or two and so on. That way you wont have to crop the edges so much.

The information your provide is very helpful. And I will try out the method you suggest. Thank you.

S

[feverdreamer1]

2 hours ago, carastro said:

Yes all long exposure not only with a tracking mount but guided too (guiding tweaks the tracking to keep it more accurate).

Nothing is cheap in Astrophotography unfortunately.

Carole 

Yeah after a few hours searching online I found out how expensive it is 🤣🤣.

But thank you for pointing me in the right direction!

S

[feverdreamer1]

I have also read about untrakced astrophotography. And I've seen some excellent results. Are they true? Can I get the same results?

Thank you in advance,

S

[carastro]

Can't imagine it, can you post up some links and examples.

Carole 

[feverdreamer1]

Links to the pages and videos:

YouTube video.

WebPage

There are many more, but these are the ones I have had time to read.

Thanks in advance

S

[x6gas]

There is quite a lot you can image with a camera and a tripod.  You said you've imaged the moon, you can also do nice nightscapes that will show the moon and bright stars, and another popular thing is to record the trailing of the stars as the Earth rotates - this is particularly effective if you point your camera lens at the pole star as the trails will appear to be circular.

Digitally stacking images together is sort of equivalent to taking a longer exposure, but there are physical characteristics of digital camera sensors that means it's not quite so...  For instance read noise is introduced each time a frame is taken so you would have 100 times more read noise in a stack of 100, 6 second exposures that you would in one 600 second exposure.  Depending on the focal length of the lens you could take a number of shortish exposures and stack them, but you would probably be limited to a fairly wide field.  I have tried this in the past with pretty poor results and in any event I don't think that approach would allow you to replicate Carole's images...

[feverdreamer1]

1 hour ago, x6gas said:

There is quite a lot you can image with a camera and a tripod.  You said you've imaged the moon, you can also do nice nightscapes that will show the moon and bright stars, and another popular thing is to record the trailing of the stars as the Earth rotates - this is particularly effective if you point your camera lens at the pole star as the trails will appear to be circular.

Digitally stacking images together is sort of equivalent to taking a longer exposure, but there are physical characteristics of digital camera sensors that means it's not quite so...  For instance read noise is introduced each time a frame is taken so you would have 100 times more read noise in a stack of 100, 6 second exposures that you would in one 600 second exposure.  Depending on the focal length of the lens you could take a number of shortish exposures and stack them, but you would probably be limited to a fairly wide field.  I have tried this in the past with pretty poor results and in any event I don't think that approach would allow you to replicate Carole's images...

Thank you for all the information you provide, but I have a question, when doing star trails, is it better to stack multiple exposure of about 30 seconds, or to take a single shot of about 30 minutes?

Thanks in advance,

S

[x6gas]

Well, the longer the exposure the more thermal noise you get but since you want to capture the apparent movement of the stars you'll want to find a happy medium and this will depend on many factors including your camera and the ambient temperature.  As with lots of things in astrophotography the best thing to do is experiment.  People on here are usually good at explaining what they have done so search for star trails in the wide-field imaging section and see if you can find some images you like taken with similar kit to yours... if they list the ISO, f-ratio, and exposure setting then that will give you a starting point (and if they don't, you can always ask!)

[JonCarleton]

OK...one word for a starter in DSOs: Globular Clusters!

Mmm..ok..two words.  But seriously, these are the brightest and easiest to spot even in highly light-polluted environments.  There are several up this time of year (summer 2020).  I particularly like M13.

I threw this image of M92 together to give you an idea of a rough image.  This is a single 2 second exposure without stacking or stretching and only sizing in GIMP for processing (read that as just making a small png file for posting).  

Edited June 27, 2020 by JonCarleton
Added IMage

[feverdreamer1]

5 hours ago, JonCarleton said:

OK...one word for a starter in DSOs: Globular Clusters!

Mmm..ok..two words.  But seriously, these are the brightest and easiest to spot even in highly light-polluted environments.  There are several up this time of year (summer 2020).  I particularly like M13.

I threw this image of M92 together to give you an idea of a rough image.  This is a single 2 second exposure without stacking or stretching and only sizing in GIMP for processing (read that as just making a small png file for posting).  

Is this without a tracker? If it isnt, then this is way more than what I had expected.

[feverdreamer1]

5 hours ago, x6gas said:

Well, the longer the exposure the more thermal noise you get but since you want to capture the apparent movement of the stars you'll want to find a happy medium and this will depend on many factors including your camera and the ambient temperature.  As with lots of things in astrophotography the best thing to do is experiment.  People on here are usually good at explaining what they have done so search for star trails in the wide-field imaging section and see if you can find some images you like taken with similar kit to yours... if they list the ISO, f-ratio, and exposure setting then that will give you a starting point (and if they don't, you can always ask!)

Thank you very much for the information. I will read and study more. AP has shown me that behind those beautiful images there are hours and hours not only of working on them but researching and experimenting.

Thanks

[JonCarleton]

The image I posted was without tracking.  I have an Alt/Az mount with tracking, but it was not on for this particular image.  2 seconds is about all I can do without star trails with tracking off.  I can manage 10-15 seconds with tracking on, but not much more without a guide scope with my mount.  Some folks would say that deep sky is impractical without an equatorial mount.  Still, using stacking, I can get some good results with lots and lots of small-duration images.

It wouldn't hurt to download some of the free image processing and stacking software packages and play a bit with that end of it.  Lots of folks here and on other forums have some of their image data online for download so people can gain experience.  That way, you can see the results that can be had from many dim single images put together and processed.

[feverdreamer1]

18 minutes ago, JonCarleton said:

The image I posted was without tracking.  I have an Alt/Az mount with tracking, but it was not on for this particular image.  2 seconds is about all I can do without star trails with tracking off.  I can manage 10-15 seconds with tracking on, but not much more without a guide scope with my mount.  Some folks would say that deep sky is impractical without an equatorial mount.  Still, using stacking, I can get some good results with lots and lots of small-duration images.

It wouldn't hurt to download some of the free image processing and stacking software packages and play a bit with that end of it.  Lots of folks here and on other forums have some of their image data online for download so people can gain experience.  That way, you can see the results that can be had from many dim single images put together and processed.

I have heard of software like Sequator, DSS and other,but for some reason DSS appears as a virus to my computer (really weird).

Anyways, if I'm being honest your picture does give me some hope that I can get some decent AP pictures this summer. In what bortle class did you shoot it?

Also, do you recall the settings you used?

Thanks,

s

Edited June 27, 2020 by feverdreamer1

[JonCarleton]

I am in Bortel 6.  I am not using a DSLR, so all I can say is 2 second exposure with gain set to about 30%.  This was not a stacked image, but one basically untouched, unprocessed shot.  I provided it as a reference.  There are some easy targets.  Simply put, the bright ones are easy.  Start with the bright ones.

What you actually see in your camera or telescope, even with a bright target, may just be a fuzzy blob (my image was not a fuzzy blob....because it was REALLY bright).  Look at some videos on YouTube about stretching an image, such as this one:

As to your computer thinking DSS is a virus...I operate in Linux.  What is a virus? 

 

Edited June 28, 2020 by JonCarleton

[iapa]

one POSSIBILITY is to

1. find a DSO that is going to be accessible during night time hours. Stellarium is a good free tool.
2. narrow that list down to this were there is a visible, or near visible, star that the camera will "see"
3. work out best exposure (I think that's roughly 400/focal length of lens) you are probably going to be 1s exposures with a 400mm lens
4. take some images of the sky with the "visible" star in centre
5. shift the image centre to include the DSO of interest
6. take as many images as you can in time available

you can stack these (Deep Sky Stacker is free) to see how things come out.

 

PS - it's Sunday Dinner so, a few libations have now been consumed

 

You can PM me tomorrow is you want.

[rickwayne]

There are also several deep sky objects that don't need a ton of magnification. In the winter the Orion Molecular Cloud Complex can be imaged with a 50mm; the North America and Pelican Nebulae are also pretty big (one of Carole's shots is of the NA). The Andromeda Galaxy won't fill the frame by any means at 135mm, but it will certainly dominate the image.

The big advantage of compositing short exposures together for star trails is that no single event can ruin your image. E.g. kicking the tripod, vehicle driving by with headlights, firefly landing on the lens...if you have one super-long exposure, any of those can tank it. If you're putting together short ones, you shrug and throw that one away. I use Photoshop and a "Maximum" stacking mode on Smart Objects, for what that's worth. You do have to be careful about the downtime between exposures, if you look carefully at this image the trails look sort of "dotted":
 

[feverdreamer1]

On 28/06/2020 at 18:27, JonCarleton said:

I am in Bortel 6.  I am not using a DSLR, so all I can say is 2 second exposure with gain set to about 30%.  This was not a stacked image, but one basically untouched, unprocessed shot.  I provided it as a reference.  There are some easy targets.  Simply put, the bright ones are easy.  Start with the bright ones.

What you actually see in your camera or telescope, even with a bright target, may just be a fuzzy blob (my image was not a fuzzy blob....because it was REALLY bright).  Look at some videos on YouTube about stretching an image, such as this one:

As to your computer thinking DSS is a virus...I operate in Linux.  What is a virus? 

 

Wow then if im being honest I feel better now. I was thinking that I wouldn't be able to capture any pictures of any DSO's due to light pollution 

Thank you very much!

S