Canon 700 + gso CC help

[Atreta]

Hi, 

I'm having some difficulties to image with my 700d and a gso CC with my 130pds scope.  Does anyone have it working properly so that could take some pictures to show me how it is setup? 

I'm trying with a 30mm spacer,  a 10mm t ring,   but the stars looked worst than without the cc.  With the 2 inch extension tube that came with the scope i can't get it to focus at all. 

Please,  if anyone could post pictures  and give some advice  will help me a lot. 

Thank you. 

[wxsatuser]

What I gather is the back focus of the CC is supposed to be 70mm but reports suggest this may be in the range 72>75mm.
Anyway, you will need the image train to be at least 70mm, this includes t-ring any spacers and 44mm for the Canon.
It sounds as though you have, 30mm spacer, 10mm t-ring and 44mm for the Canon, so approx 84mm, to long???

[Adam J]

24 minutes ago, wxsatuser said:

What I gather is the back focus of the CC is supposed to be 70mm but reports suggest this may be in the range 72>75mm.
Anyway, you will need the image train to be at least 70mm, this includes t-ring any spacers and 44mm for the Canon.
It sounds as though you have, 30mm spacer, 10mm t-ring and 44mm for the Canon, so approx 84mm, to long???

yep that is about correct it leaves the dslr miles away from the scope and can result in tilt. I hate to say it but this CC is not a great match for your equipment.

[alacant]

Hi. Must be honest with you. From bitter experience, I can't recommend this. The correct spacer is a 20mm m48, giving you 75mm for your 650mm focal length. 2 problems:

- The combination needs 8cm of focus away from the tube

- It increases the focal length giving a -noticeably- narrower field of view whilst at the same time slowing the focal ratio.

Even with a proper r&p focuser, it's unstable and a nightmare to balance. With the flimsy sw Crayford?

Of course YMMV but HTH anyway.

 

[Atreta]

8 hours ago, wxsatuser said:

 Anyway, you will need the image train to be at least 70mm, this includes t-ring any spacers and 44mm for the Canon.
It sounds as though you have, 30mm spacer, 10mm t-ring and 44mm for the Canon, so approx 84mm, to long???

Thanks.

I'have also a low profile t ring,  gonna try with it. 

8 hours ago, Adam J said:

yep that is about correct it leaves the dslr miles away from the scope and can result in tilt. I hate to say it but this CC is not a great match for your equipment.

Thanks,  i bought it a while ago and it is so hard to find good astronomy equipments in here,  our best store has closed down.  Maybe sell it and buy another one from overseas. If you can recommend one. 

6 hours ago, alacant said:

Hi. Must be honest with you. From bitter experience, I can't recommend this. The correct spacer is a 20mm m48, giving you 75mm for your 650mm focal length. 2 problems:

- The combination needs 8cm of focus away from the tube

- It increases the focal length giving a -noticeably- narrower field of view whilst at the same time slowing the focal ratio.

Even with a proper r&p focuser, it's unstable and a nightmare to balance. With the flimsy sw Crayford?

Of course YMMV but HTH anyway.

 

Thanks,  maybe i could sell this one and try to import a better,  do you have any recommendation?  

[alacant]

14 minutes ago, Atreta said:

recommendation

There's this and this. Shop around for import deals. The former needs the focus tube cutting to prevent d shaped stars but gives you an addictive 580mm f4.5. Some use the Baader corrector but IMHO it gives fatter stars. HTH.

*a selling point for the gso cc is that it can save you having to modify tubes of telescopes with insufficient back focus. 

[Atreta]

Thanks everyone for the help,  i'll try to stick with it for a while and see if i can make it work, and later import a better suited one.