Camera and spacers

[capability darwin]

Hi. Apologies for the complete newb question - I’ve just ordered an Altair 0.8 reducer for the 60EDF telescope which the specs say requires 55mm spacing. I have a Altair GPCAM3 290c camera which I believe has 12.5mm back focus. Am I correct in thinking I just need 42.5mm worth of spacers to reach focus? 

Plus, does the camera just screw into the final spacer and is this a specific diameter? Thanks. 

 

[pipnina]

Hi and welcome to the forum!

The reducer has a male M48 thread, but the camera is C-mount which has a 1 inch imperial thread, so they won't mesh together without some sort of adapter.

You will need this adapter to thread the camera into: https://www.firstlightoptics.com/adapters/astro-essentials-low-profile-female-t-thread-to-male-c-thread-adapter.html

And this adapter to step the first adapter's thread size up from M42 to M48. https://www.firstlightoptics.com/adapters/astro-essentials-m48-to-m42-t2-adapter.html

These add 8+6.5mm to the spacing between camera and corrector, and since the camera itself has 12.5mm that brings us up to 27mm, but needing 55.

So we need this set of extension pieces: https://www.firstlightoptics.com/adapters/astro-essentials-m48-extension-tube-set-4mm-5mm-6mm-7mm-8mm-9mm.html

9mm, plus 8mm plus 7mm plus 4mm on top of our 27mm = 55mm back focus!

Hope this helps! Won't hurt to throw the people at firstlight optics an email to check and make sure those are definitely the right parts for the job, but it all makes sense to me as-is!

Hope you get the best from your kit!

 

[capability darwin]

That’s great. Thank you! 

[AstroMuni]

On 27/10/2022 at 16:51, capability darwin said:

I have a Altair GPCAM3 290c camera which I believe has 12.5mm back focus. Am I correct in thinking I just need 42.5mm worth of spacers to reach focus?

Does the camera come with spacers? Some of the ASI cooled cameras tend to come with spacers, hence my question.