Suggestions for a longer refractor for my next imaging scope

[Elp]

Newtonians are very easy to collimate with a simple collimation cap, it helps greatly if the primary is centre dotted.

[Spile]

Collimation is very easy just difficult to write about. Think about the physics behind riding a bike , yet we learn to do it as kids. https://astro.catshill.com/collimation-guide/

[900SL]

superceded

Edited October 3, 2022 by 900SL

[900SL]

Well, I've done the usual all round the houses twice on this one. Which is a good thing, as I think I had aperture fever combined with a case of keeping up with the Jones's.

On reflection (or should that be refraction), and after carefully considering my set up, preferences and having a good look at telescopius framing, the scope that seems to make the most sense is a 90mm f6 TS CF APO 

This seems to be a good match to the 533MC and D5600, in terms of resolution and FOV.  

It also has the advantage that I can use my existing WO 6Aiii 0.8 flattener/reducer, or use a Barlow for lunar etc

It won't overload my SXD2 mount, should give me a reasonably portable set up, and guiding should be a breeze.

Its not a big step up from the GT71 but I'll probably sell that, as the TS 90 is a better match I think.

My primary interest is widefield nebula, the usual suspects. I've still got a long way to go with imaging and processing, so don't intend to go much deeper for quite a while.

That will leave me with a Samyang 135 wide field, a Redcat 51 wide field (both for portable travel use with a Fornax LT)  and a 90mm for getting in closer on the SXD2

[raadoo]

1 hour ago, 900SL said:

Well, I've done the usual all round the houses twice on this one. Which is a good thing, as I think I had aperture fever combined with a case of keeping up with the Jones's.

On reflection (or should that be refraction), and after carefully considering my set up, preferences and having a good look at telescopius framing, the scope that seems to make the most sense is a 90mm f6 TS CF APO 

This seems to be a good match to the 533MC and D5600, in terms of resolution and FOV.  

It also has the advantage that I can use my existing WO 6Aiii 0.8 flattener/reducer, or use a Barlow for lunar etc

It won't overload my SXD2 mount, should give me a reasonably portable set up, and guiding should be a breeze.

Its not a big step up from the GT71 but I'll probably sell that, as the TS 90 is a better match I think.

My primary interest is widefield nebula, the usual suspects. I've still got a long way to go with imaging and processing, so don't intend to go much deeper for quite a while.

That will leave me with a Samyang 135 wide field, a Redcat 51 wide field (both for portable travel use with a Fornax LT)  and a 90mm for getting in closer on the SXD2

I think you went about it the best way possible, by building an arsenal that [almost] doubles focal length with each step. Camera and sampling notwithstanding, this is likely the best way to grow into ever more magnification without hitting that proverbial learning curve too hard.

You've now got:

• 135mm (Samy)
• 250mm (Redcat)
• 540mm (TS)

Looking into my crystal ball, your next additions should be something like:

• 1000mm (8" f/5 Newt)
• 2032mm (8" SCT)
• 3910mm (14" SCT)

Looking forward to seeing if my predictions turn out. 😊

[900SL]

😂 thanks Raadoo

Well .. the max load out is 14kilo on the SXD2 and I don't really want to push it to the max...