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.



IC1396, Elephant’s Trunk

Recommended Posts

My fourth (I think) narrowband image, more lessons learned on this one

First, meridian flips go in two steps! I told EQMod to force a flip then went scurrying out to the dome to see it in action, I found it merrily swinging over as planned and it stopped just a few inches from the mount. All was good until a second later it started moving again! I quickly switched off the power to the mount and (I thought) avoided a catastrophic smashing of telescope into pier. I then went through the very painful process of setting the home position before trying it again, this time I went out with a laptop and VNC’d to the PC inside to try again – lo and behold, we flip to the meridian then stop before finally moving to the target (which was just off the meridian). So if I had just waited 1-2 seconds it would have been perfectly positioned. Another one chalked up to experience!

The next lesson was to remember your filter order!! I spent 2 nights imaging in Hb which I didn't want! I thought I was on the OIII filter and wasted two clear nights

On the plus side I am now able to get back to the same spot in Cartes Du Ciel when there are no stars to use as a reference and I have a dome which works properly with new infra red sensors rather than a timer

The imaging went like this:

5.5 hours of Ha (+6hrs darks + 50 bias)
6 hours of Hb (+8hrs darks + 50 bias)
4.5 hours of OIII (+8hrs darks + 50 bias)
3 hours of SII (+8hrs darks + 50 bias)

I really found the benefit of getting several hours of data for noise removal, previous efforts of 1-3 hours were nowhere near as clean.  I'll spend a while playing with the image now but fairly happy with it so far


  • Like 7

Share this post

Link to post
Share on other sites

Looks good.  Yes, the mount (at least mine) will move slowly, stop then move at accelerated rate--or vice versa.  I think its a safety feature.  Doesn't your acquisition software label your filter positions?  That helps if you forget what is where.   Did you actually collect darks for every channel?  If your subs are teh same length and the same temperature, you can use the same darks. 


Share this post

Link to post
Share on other sites

Exactly right, every night is a new lesson!

Yes I've labelled the filters in both Artemis and Nebulosity but both seem to forget them for some reason

I collected darks on each filter because the focus was slightly different for each so I thought it would have an effect but not sure? With hindsight that doesn't make much sense so maybe wasted a few dozen hours!!

Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • 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.