Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep28_banner.thumb.jpg.b94278254f44dd38f3f7ee896fe45525.jpg

Sign in to follow this  
Crackabarrel

NGC6960

Recommended Posts

Seeing as its Halloween season I decided to go for NGC6960 this weekend.

First attempt at guiding, trying not to stress too much over the graph as long as subs come out alright.

Moon definitely didn't help contrast though.

Also first experience using PS and the Carboni Astronomy toolset.

Any suggestions or criticism would be appreciated, thanks.

EDIT: Kit List:
WO ZS 73 + 50mm Guidescope w/ ASI120mm , HEQ5 Pro, Nikon D5300, IDAS LPS D2

NGC6960Finished.jpg

Edited by Crackabarrel
  • Like 2

Share this post


Link to post
Share on other sites

Very good, maybe more data would help and also star reduction. There also seems to be a magenta caste to the background, easy to fix by inverting the image and removing green then re-invert.

  • Thanks 1

Share this post


Link to post
Share on other sites
4 minutes ago, MarkAR said:

Very good, maybe more data would help and also star reduction. There also seems to be a magenta caste to the background, easy to fix by inverting the image and removing green then re-invert.

Cheers Mark,

I'll give that a try and see how I get on.

Share this post


Link to post
Share on other sites
3 hours ago, Crackabarrel said:

First attempt at guiding, trying not to stress too much over the graph as long as subs come out alright.

The stars look good and sharp so it seems to be fine.

I've not been guiding very long and but I remember, while researching PHD2, seeing/watching someone who said that as a long as the total error is less than 1 arc second then you should be fine, even if the graph looks a mess. :D

My EQ5 mount is normally between 0.45 & 0.75 for the total and it seems to work fine. ;)

  • Thanks 1

Share this post


Link to post
Share on other sites
10 minutes ago, Budgie1 said:

The stars look good and sharp so it seems to be fine.

I've not been guiding very long and but I remember, while researching PHD2, seeing/watching someone who said that as a long as the total error is less than 1 arc second then you should be fine, even if the graph looks a mess. :D

My EQ5 mount is normally between 0.45 & 0.75 for the total and it seems to work fine. ;)

Cheers, I'd seen that recommendation before yeh, once the guiding had settled down initially I was getting values under 1arc/sec, however it seemed to creep up into the 3s and 4s over the session, but the majority of subs were coming out fine which had me scratching my head.

  • Like 1

Share this post


Link to post
Share on other sites

Good Polar Alignment and mount levelling seems to be key. 

I always used to use the polar scope but now I have the guide camera attached and it's linked up to the laptop, I went for the SharpCap Pro and use the Polar Alignment tool on that. It's easy to use and saves getting your knee wet! :D

Share this post


Link to post
Share on other sites

Sharpcap Pro is next on the list once I work out how to use EQMod properly.

Was reading you need to rotate on RA 90deg for Sharpcap to work, is this set in stone or is there some leeway? 

My backyard observing site would preclude me from going the full 90deg due to neighbor's houses

Share this post


Link to post
Share on other sites

Nice image. No feedback regarding that because I don't use photoshop to edit. Maybe more data (you don't say how much you have?) will help clean things up a bit.

Regarding the guiding, my understanding is that the amount of error that is permissible is based on the resolution of your system. For example if you're using something like an ASI533 with a 135mm lens then your resolution is going to be somewhere around 5.7"/pixel. So as long as your guiding is less than that, your stars will be round.

If, however you're using the 533 with a Celestron 8SE with a focal length of over 2meters, then your resolution is going to be closer to 0.4"/pixel and your guiding needs to be bang on or you'll see eggy stars. To be honest, at that resolution you're likely to be more limited by the sky conditions like seeing and clarity than anything else.

That's my understanding anyway! Someone may come along and correct me :)

Phil

  • Thanks 1

Share this post


Link to post
Share on other sites
12 minutes ago, Phillyo said:

Nice image. No feedback regarding that because I don't use photoshop to edit. Maybe more data (you don't say how much you have?) will help clean things up a bit.

Regarding the guiding, my understanding is that the amount of error that is permissible is based on the resolution of your system. For example if you're using something like an ASI533 with a 135mm lens then your resolution is going to be somewhere around 5.7"/pixel. So as long as your guiding is less than that, your stars will be round.

If, however you're using the 533 with a Celestron 8SE with a focal length of over 2meters, then your resolution is going to be closer to 0.4"/pixel and your guiding needs to be bang on or you'll see eggy stars. To be honest, at that resolution you're likely to be more limited by the sky conditions like seeing and clarity than anything else.

That's my understanding anyway! Someone may come along and correct me :)

Phil

Ah thank you, that makes sense regarding why I was seeing round stars with the error values I was seeing.

Capture data was as follows:

55 x 120sec exposure @ IS0400
25 x Dark

40 x Flat

40 x Bias

  • Like 1

Share this post


Link to post
Share on other sites
10 minutes ago, City9Town0 said:

Sharpcap uses 'about 90 degrees' but manages with less....

Cheers that clears up any potential issues

Share this post


Link to post
Share on other sites
8 minutes ago, Crackabarrel said:

Ah thank you, that makes sense regarding why I was seeing round stars with the error values I was seeing.

Capture data was as follows:

55 x 120sec exposure @ IS0400
25 x Dark

40 x Flat

40 x Bias

If you're using a DSLR, unless it's cooled, I wouldn't bother with dark frames either. Temperature variances can often mean that using darks as part of the calibration and integration frames can cause more problems than not.

  • Thanks 1

Share this post


Link to post
Share on other sites
56 minutes ago, Phillyo said:

If you're using a DSLR, unless it's cooled, I wouldn't bother with dark frames either. Temperature variances can often mean that using darks as part of the calibration and integration frames can cause more problems than not.

Its just a stock D5300.

I'll see if stacking without the darks makes a difference so, thanks.

Share this post


Link to post
Share on other sites
3 hours ago, Phillyo said:

Nice image. No feedback regarding that because I don't use photoshop to edit. Maybe more data (you don't say how much you have?) will help clean things up a bit.

Regarding the guiding, my understanding is that the amount of error that is permissible is based on the resolution of your system. For example if you're using something like an ASI533 with a 135mm lens then your resolution is going to be somewhere around 5.7"/pixel. So as long as your guiding is less than that, your stars will be round.

If, however you're using the 533 with a Celestron 8SE with a focal length of over 2meters, then your resolution is going to be closer to 0.4"/pixel and your guiding needs to be bang on or you'll see eggy stars. To be honest, at that resolution you're likely to be more limited by the sky conditions like seeing and clarity than anything else.

That's my understanding anyway! Someone may come along and correct me :)

Phil

Problem with that is the value of error corresponds with the guidescope/ camera and often referred in pixels.. so a short fl guidescope will be sampling far differently to the image scale of the imaging scope/ camera

Edited by newbie alert
Added info

Share this post


Link to post
Share on other sites

Great job on imaging and a big tick off the list for first time guiding.. onwards and upwards 

  • Thanks 1

Share this post


Link to post
Share on other sites
20 minutes ago, newbie alert said:

Problem with that is the value of error corresponds with the guidescope/ camera and often referred in pixels.. so a short fl guidescope will be sampling far differently to the image scale of the imaging scope/ camera

That's true. I always used OAG so my guiding was done at the same focal length as the imaging.

Share this post


Link to post
Share on other sites
7 minutes ago, Phillyo said:

That's true. I always used OAG so my guiding was done at the same focal length as the imaging.

Yeah that's true.. 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.