The "No EQ" DSO Challenge!

[Heskyyyyy]

Thanks for your responses, I'll totally keep that in mind when I get back to experimenting.

[Heskyyyyy]

 

 

My take on the Messier 3 globular, with 65, 15 second subs at iso 1600.

Edited July 4, 2020 by Heskyyyyy

[Stub Mandrel]

A play with curves could brighten that up and keep the sky background dark and make it look even nicer.

[Heskyyyyy]

11 hours ago, Stub Mandrel said:

A play with curves could brighten that up and keep the sky background dark and make it look even nicer.

Ok, I'll keep that in mind. Thanks

[Heskyyyyy]

So it seems like the most my telescope can handle is 15 seconds consistently. What are some targets y'all suggest, or how can I use this the the best of my abilites?

[happy-kat]

Is that 15 seconds in all directions?

Or are you working with a very long focal length

[The Admiral]

58 minutes ago, Heskyyyyy said:

So it seems like the most my telescope can handle is 15 seconds consistently.

What mount are you using to track the heavens? The maximum exposure I've used with my NexStar Alt-Az is 30 seconds without getting too many streaky subs, though others have managed to use a little longer. At the end of the day though you will be limited by physics, in that you will get field rotation. Lowest towards the East and West, and worse as you increase altitude towards the zenith. I used to limit it to 60°.

Ian

[groth12345]

4 hours ago, The Admiral said:

What mount are you using to track the heavens? The maximum exposure I've used with my NexStar Alt-Az is 30 seconds without getting too many streaky subs, though others have managed to use a little longer. At the end of the day though you will be limited by physics, in that you will get field rotation. Lowest towards the East and West, and worse as you increase altitude towards the zenith. I used to limit it to 60°.

Ian

That's pretty good with the Nexstar.  Mine would be good in the east/west for about 20-30 sec but I'd still have to toss about 50% of the subs out.  Now using an Evo mount and it's much better.  Probably 80% usable subs as long as close to the east/west horizons.

 

[Heskyyyyy]

22 hours ago, happy-kat said:

Is that 15 seconds in all directions?

Or are you working with a very long focal length

From what I've done so far, yes 15 seconds, and still a bit of trailing in some frames. Might try 10 seconds instead. I have a 6se, 1500mm

[Heskyyyyy]

23 hours ago, The Admiral said:

What mount are you using to track the heavens? The maximum exposure I've used with my NexStar Alt-Az is 30 seconds without getting too many streaky subs, though others have managed to use a little longer. At the end of the day though you will be limited by physics, in that you will get field rotation. Lowest towards the East and West, and worse as you increase altitude towards the zenith. I used to limit it to 60°.

Ian

Which stars did you use to align the nexstar normally? I'm thinking the reason my subs are so short are because I usually use Polaris as an alignment star.

 

Thanks

[The Admiral]

8 minutes ago, Heskyyyyy said:

Which stars did you use to align the nexstar normally? I'm thinking the reason my subs are so short are because I usually use Polaris as an alignment star.

 

Thanks

My, possibly spurious, understanding is that when you perform an alignment what you are doing is getting a fix on where stars are at a point in time, so that the 'model' is calibrated. But Polaris doesn't change position with time, and so is rather less than helpful in getting a 'fix'. I would not recommend using Polaris for alignment. I also try to align on stars which are approximately 90° apart in azimuth, as it strikes me that using orthogonal axes would improve the precision. I choose bright stars between 40° and 60° altitude as well as separated by about 90° in azimuth. In addition I always level the mount so as to minimize the corrections that have to be made to get the model 'fixed'. I normally just used a 2-star alignment.

Ian

[Heskyyyyy]

1 hour ago, The Admiral said:

My, possibly spurious, understanding is that when you perform an alignment what you are doing is getting a fix on where stars are at a point in time, so that the 'model' is calibrated. But Polaris doesn't change position with time, and so is rather less than helpful in getting a 'fix'. I would not recommend using Polaris for alignment. I also try to align on stars which are approximately 90° apart in azimuth, as it strikes me that using orthogonal axes would improve the precision. I choose bright stars between 40° and 60° altitude as well as separated by about 90° in azimuth. In addition I always level the mount so as to minimize the corrections that have to be made to get the model 'fixed'. I normally just used a 2-star alignment.

Ian

Thanks a lot for the helpful advice. I'll try to avoid Polaris next time I can get out. I'll also keep playing around with exposure times to try to find the ultimate limit for my telescope.

[Nerf_Caching]

22 hours ago, Heskyyyyy said:

Thanks a lot for the helpful advice. I'll try to avoid Polaris next time I can get out. I'll also keep playing around with exposure times to try to find the ultimate limit for my telescope.

My setup is similar to yours but I'm using a Celestron Nexstar 5SE and a stock Canon 650d. This is 15 minutes on M4 using 30-second exposures. Try to photograph stuff due east or west for better tracking.

[Heskyyyyy]

4 hours ago, Nerf_Caching said:

My setup is similar to yours but I'm using a Celestron Nexstar 5SE and a stock Canon 650d. This is 15 minutes on M4 using 30-second exposures. Try to photograph stuff due east or west for better tracking.

Very nice capture. Alright, thanks

[JonCarleton]

I usually shoot 10 second exposures, but I get lots and lots and lots of subs.  While I do recognize that 100 10 second subs does not equal 10 10 minute subs, it probably comes close to half the light of a long exposure collection.  After stacking, I get pretty good light density....and all but eliminate the shortcomings of my Alt/Az tracking.

Edited July 11, 2020 by JonCarleton

[Heskyyyyy]

1 hour ago, JonCarleton said:

I usually shoot 10 second exposures, but I get lots and lots and lots of subs.  While I do recognize that 100 10 second subs does not equal 10 10 minute subs, it probably comes close to half the light of a long exposure collection.  After stacking, I get pretty good light density....and all but eliminate the shortcomings of my Alt/Az tracking.

Very encouraging. I think if possible I'll get data of the same target over multiple clear nights.

[Stub Mandrel]

On 09/07/2020 at 17:08, Heskyyyyy said:

From what I've done so far, yes 15 seconds, and still a bit of trailing in some frames. Might try 10 seconds instead. I have a 6se, 1500mm

That's a very long focal length for Alt-Az imaging... might be some sort of record!

[Heskyyyyy]

Bode's Galaxy. Avoiding Polaris as an alignment star was extremely wise, as I was able to get all 15 second exposures (ISO 1600) with minimal to zero trailing. 71 subs. Target was to the North, so I couldn't really get rid of the blue background, or maybe I'm just bad at processing 😛

Edited July 17, 2020 by Heskyyyyy

[Nerf_Caching]

33 minutes ago, Heskyyyyy said:

Bode's Galaxy. Avoiding Polaris as an alignment star was extremely wise, as I was able to get all 15 second exposures (ISO 1600) with minimal to zero trailing. 71 subs. Target was to the North, so I couldn't really get rid of the blue background, or maybe I'm just bad at processing 😛

Do you have the unprocessed stacked file? Maybe we can help you out with processing. What was the total integration time?

[Heskyyyyy]

2 hours ago, Nerf_Caching said:

Do you have the unprocessed stacked file? Maybe we can help you out with processing. What was the total integration time?

About 18 mins. I use GIMP to process. For all of y'all too, y'all have any tips for better results? I live far up north such that it never gets completely dark at night in the summer, and a target in the North really shows that blue.

 

bodes galaxy.TIF

[Heskyyyyy]

Cigar Galaxy, with 17 minutes worth of exposures.

[gaz81]

Love this thread 🙂

[gaz81]

Recent go at Neowise

[Stub Mandrel]

On 17/07/2020 at 16:48, Heskyyyyy said:

Bode's Galaxy. Avoiding Polaris as an alignment star was extremely wise, as I was able to get all 15 second exposures (ISO 1600) with minimal to zero trailing. 71 subs. Target was to the North, so I couldn't really get rid of the blue background, or maybe I'm just bad at processing 😛

Hi, hope you don't mind, I took a screen grab of your image and pasted it as an image in Photoshop.

I cropped off the dotted line, created a mask to exclude the galaxy and ran gradient exterminator. This balanced the background colour to a neutral dark grey.

Then I applied a flattened S-shaped curve to brighten the faint parts fo the galaxy (but not the very darkest bits) while not blowing out the stars. You need to experiment.

Then I ran an 'increase star colour' action 2 or 3 times.

It coudl do with noise reduction and tweaking to smooth the background, but you get the idea.

It's worth you persevering with your original data, 99% of the hard work is processing!

 

[Heskyyyyy]

4 hours ago, Stub Mandrel said:

Hi, hope you don't mind, I took a screen grab of your image and pasted it as an image in Photoshop.

I cropped off the dotted line, created a mask to exclude the galaxy and ran gradient exterminator. This balanced the background colour to a neutral dark grey.

Then I applied a flattened S-shaped curve to brighten the faint parts fo the galaxy (but not the very darkest bits) while not blowing out the stars. You need to experiment.

Then I ran an 'increase star colour' action 2 or 3 times.

It coudl do with noise reduction and tweaking to smooth the background, but you get the idea.

It's worth you persevering with your original data, 99% of the hard work is processing!

Wow that looks beautiful, and thanks for the tips!