Starlight xpress SXVF-M25C backfocus distance?

[bendiddley]

Does anyone know the distance from the chip to the outer edge of an SXVF-M25c? Is this called the back focus? I’m trying to get the spacing right with my skywatcher coma corrector. Cheers. 

[mikeyj1]

I am sure someone has one here and can help you, but i also recommend you go to/join the SX forum, Terry will answer you very quickly...it's a good resource also for any other issue

[WanderingEye]

4 minutes ago, mikeyj1 said:

I am sure someone has one here and can help you, but i also recommend you go to/join the SX forum, Terry will answer you very quickly...it's a good resource also for any other issue

Can you send me a link to that forum, as I would like to join, but can’t find... 👍

[mikeyj1]

groups.yahoo.com

and search for 'Starlightxpress'

its 'restricted group' so you have to apply to join, but easy enough

you can also get to it from sxccd.com 'message board' section

Mike

[bendiddley]

11 minutes ago, mikeyj1 said:

groups.yahoo.com

and search for 'Starlightxpress'

its 'restricted group' so you have to apply to join, but easy enough

you can also get to it from sxccd.com 'message board' section

Mike

Thanks guys. I’ll go and check this place out. 

[Bantam]

Acording to the SX website, the latest version of the M25C has a back focal length of 17mm +/- 1mm

If you join the SX usergroup, Terry Platt will be able to confirm that. From my experience, he is always really helpful

HTH

Edited September 28, 2019 by Bantam

[bendiddley]

6 minutes ago, Bantam said:

Acording to the SX website, the latest version of the M25C has a back focal length of 17mm +/- 1mm

If you join the SX usergroup, Terry Platt will be able to confirm that. From my experience, he is always really helpful

HTH

Many thanks. I’ve just joined, approval pending. 

[DougM43]

Dose that help any?  It’s how I worked it out with mine 

Doug.

[bendiddley]

8 minutes ago, DougM43 said:

Dose that help any?  It’s how I worked it out with mine 

Doug.

Brilliant! As it happens I have all those parts too. 

[bendiddley]

I'll take that back, I don't have the 6mm t2 extension, only a 7.5mm, but I guess if I make the varilock 1.5mm shorter, so 22.5mm instead, that should sort it.

[bendiddley]

I've just had a reply from Terry on the starlight xpress yahoo group and he says it's approx 17mm. I'm going to set my baader varilock to allow for this and see how it goes. I will report back my findings.