Spacing of the Borg 77ED

[alan potts]

Is it possible for any of you eagle eyed members to tell me which way the  spacing is out from this shot of the Soul Neb, is it too short or too long.

I am not totally sure it is focused spot on, a task i have to say I fine very difficult with this new to me type of focus ring, seems as if you need to move it a millionth of a millimeter. To get this close took me 25mins

I need to achieve a spacing of 37.5mm and at the moment I feel I am close using a slimmer than required spacing ring and some tape wrapped round as getting the correct equipment at this time of year is risky with post, and in any case I haven't found anyone that sells it other than TS.  I am even considering taking 1mm off the 21mm ZWO sleeve as I have two.

This is an hour I grabbed last night with the 183MC at 20x3min subs with darks and flats.

 

Alan

[spillage]

I'm certainly not an expert but I would say it needs to increase just a little.

cheers

[alan potts]

2 hours ago, spillage said:

I'm certainly not an expert but I would say it needs to increase just a little.

cheers

Thank you for that, I fully see it is not easy to see the elongation as I also feel I have induced a very small tilt into the image plain with my half baked idea. Seems to me with this scope everything is the tiniest adjustment, not easy at all.

Alan

[spillage]

Might be worth running some subs through ccd inspector or maxpilote. This should help show any tilt.

[alan potts]

14 hours ago, spillage said:

Might be worth running some subs through ccd inspector or maxpilote. This should help show any tilt.

I will after Christmas seek the correct sleeve to give me the 37.5mm. As it stands I have the Zwo 21mm sleeve in the mix so finding a 20mm one should not be so difficult, it's just with it being a difficult time for the Post. I find it difficult to understand that even maybe 0.1-0.2mm can make so much difference.

Thanks for you help.  Alan

[spillage]

I am sure you will find the sweet spot. I have found that going over in both directions has given me a better idea on which way to go. I am sure my baader mpcc is no way near the manufacturers spacing but by going a good few mm under and over got me moving the right way and packet of delrin spacers helped me out in the end. 

I understand you reason for waiting and also the time it takes up to get it right. As I do not have a proper observatory I found working outside and due to the UK weather it took longer than it should have.

[alan potts]

4 hours ago, spillage said:

I am sure you will find the sweet spot. I have found that going over in both directions has given me a better idea on which way to go. I am sure my baader mpcc is no way near the manufacturers spacing but by going a good few mm under and over got me moving the right way and packet of delrin spacers helped me out in the end. 

I understand you reason for waiting and also the time it takes up to get it right. As I do not have a proper observatory I found working outside and due to the UK weather it took longer than it should have.

The only thing I would say is Borg do have a very good name and if the say a back focus is 37.5mm then I guess it will be. Can't say I have had that much luck with the large TS Red reducer on my APO. It is stated at 55mm and seems a tad out, then I can't get a IR UV filter into the light path without spending rather a lot for what it is. The Borg is with it's own reducer not a 3rd party so it should just be a case of getting it right. Still finding focus a pain though. At least mine is in an observatory, though this scope looks rather silly on the CEM 60, it was a good job I didn't get the 120 version that i almost did. I feel the Borg has a good scope in it though, just a case of digging it out.

Alan