Can't achieve focus on Lunt 50 with 2x Powermate

Lunt LS50THa Help Needed Troubleshooting
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Paul Larkin avatar
Paul Larkin avatar
Hi, folks.
I have a Lunt 50 with 600 BF and Saturn-M SQR camera.  It works a treat.

I've tried attaching my Televue 2x Powermate (2" version) but cannot achieve focus.  It seems I need to be closer in than I can manage.  I have read that the 50 is not ideal for imaging, but one must have a go.
It makes no difference which side of the BF I place it.  I have also used a female-to-female adaptor to get the BF snug against the focuser, but it is still not enough.  The Powermate has the T2 adaptor to which the camera is screwed directly and the Powermate is screwed to the BF.  Everything is as short as possible.  I’ve also tried going longer (in case I was misreading things) but that is not the solution.

I see that others have used Barlows and Powermates succesfully (e.g. @rigel123 who uses a 'short Barlow' on his Lunt 60).  I wonder if it is just that I am using the 2" Powermate instead of a 1.25" and that there is something different in the focusing?  Struggling to find anything on the various forums.  Does so-called ‘short Barlow’ address this issue? I am surely missing a trick here somewhere.

​​​​​​​Any help will be most appreciated.
Cheers.
Paul
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rigel123 avatar
rigel123 avatar
I can use pretty much any barlow with my 60 mm.  The Powermate always introduced a reflection which is why I don’t use one.  Those that I have seen have success imaging with the 50 remove the nosepiece of the camera and screw it onto the barlow which sounds like you have already tried.  Hopefully someone that has had success with the same equipment will help you out.  The other option is to replace the focuser.
andrea tasselli avatar
andrea tasselli avatar
THe body of the 2x PM is just too long. You should try with the Celestron 2x Ultima Barlow, if you can find one or otherwise the X-Cell one. Taka's is also good.
Paul Larkin avatar
Paul Larkin avatar
Many thanks, Andrea and Warren.
Andrea, I'll check out your suggestions for Barlows.
You have both been super helpful.
All the best.
Paul
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rigel123 avatar
rigel123 avatar
I don't know if you are on Solar Chat but Brendant is taking wonderful images with his 50mm Lunt with a Neptune One camera.  You might want to contact him to see how he sets up.

https://solarchatforum.com/viewtopic.php?t=47230
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Eddie Bagwell avatar
Eddie Bagwell avatar
A shorter barlow is the answer as stated above. I use the Celestron X-Cel 2x and 3x on my setup but with a larger Lunt. Finding focus the first time with new accessories can be a challenge working with Solar.
Bob Lockwood avatar
Bob Lockwood avatar
Paul Larkin:
I wonder if it is just that I am using the 2" Powermate instead of a 1.25" and that there is something different in the focusing?


I think you have the answer hear with the 2" version, the 2" 2x PM is almost 1.5" longer then the 1.25" version. Not sure if there is that much difference in the 50 and 60, but 
I've used the 1.25" version of the 2.5x and 5x PM when I had my Lunt 60.
Paul Larkin avatar
Paul Larkin avatar
Thanks, Eddie and Bob.
I think the 50 presents a different challenge, having a shorter focus than the 60 but this is very helpful.
Cheers.
Paul
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