Problems Screwing Adapter into 9x50 Finder Scope

[PhotoGav]

Morning all,

I hope you enjoyed a clear night last night, well it was clear in Wiltshire anyway. I was able to get out with a new (to me) 8" Celestron. My plan was to start trying to get guiding going.

However, my plan was scuppered when I failed to focus the finder scope with my QHY5-II. I have the Modern Astronomy adapter and have used it successfully with my Skywatcher 9x50 finder, which is the same as the Celestron 9x50, allegedly. The problem is that it only screws a small way into the Celestron finder, not the whole way as it does with the Skywatcher finder. So, any ideas how I can solve this one? My thoughts are:

1. There must be some problem with the thread in the Celestron Finder - can that be sorted?

2. The adapter is not right for the Celestron - I don't think that is the case?

3. I could mount the Skywatcher finder, that works perfectly, on to the Celestron tube - what is the best method to do that so that I can easily swap from 8" to 80ED when I need to?

4. Just spend even more money and buy an OAG for the Celestron and ditch the finder (or leave it on to use as a finder scope) - expensive option, but which would be the best one to go for?

So, please, all thoughts, advice and help gratefully received.

[Tinker1947]

I have the Skywatcher and the Celestron finder scopes my Adapter fits the Skywatcher ok the Celestron it goes in maybe 2-3 turns so i would think its a different thread pitch.......Modern Astronomy sell the Adapters a phone call to Bernard might be the way to go.....

[redfox1971]

Yep 2 differnt types of adapters for the celestron cpc800 finderscope the first I had from bern was wroung one mine was not the common 1 so returned and was sent correct one.

[knobby]

Could you not screw it in as far as it goes and then try adjusting the front element to focus ... I think it moves ?

[redfox1971]

Also I have tried the off axis guider route with the Orion delux off axis guider and qhy5 and could never find a star in the area of imageing.

[Tinker1947]

This guider has a large prism, i have one but not had the chance to test it.......

http://www.firstlightoptics.com/off-axis-guiders-oag/celestron-off-axis-guider-sct.html

[PhotoGav]

Thank you all very much for your speedy and helpful replies. I tried moving the front element, but it doesn't move far enough. Looks like it is a different adapter that is needed. I have emailed Bernard and will speak with him tomorrow. Also looks like I will manage to avoid the tricky OAG route for now. Hopefully the solution will be implemented before the clear, dark skies return... Should give me a while!