Combining and/or stacking Newton with Refractor Data

andrea tasselli:
More like the triple of the light with the 6", more likely a little over the 3:1 ratio. Being a fast newtonian it requires careful collimation at least intially so this is a given. And a coma corrector and a good one too. Otherwise, if the mount can handle a side-by-side arrangement, you are good to go. As for the data, if you are careful about what you are doing yes, that shouldn't be a problem other than for the choice of stars with spike or no spikes.

Thanks, Andrea.

The two scopes are 1 stop in difference (f4 to f5.5), so the newtonian should be twice as fast as the Esprit. If it is just as sharp, then I would be very happy.

My remaining concerns are about the collimation and how well the scope can hold it. I am planning on goinf remote for this summer and ideally, the parallel scopes would be installed there.

Does anyone know if ONTC lose collimation easily if they are not carried around and installed on a pier?

The other issue would be the mount, which would need an upgrade to somethinf with more load capacities.

A lot of unknown factors, the project sounds appealing as I could gather more light and maximize the time going remote.

Hi David,

I have already put your idea into practice, even with an more different combination:

• Luminance: 34 x 300‘’ > G2-8300 + Newton 250/1000mm
• RGB: 33 x 300‘’ > ASI2600MC-Pro + SkyWatcher 80/600mm, with reducer 510mm

My intention was to get an object finished in one night. I already had the two telescopes independently of each other and had not purchased them separately for this experiment. The Skywatcher refractor was piggybacked onto the Newtonian. 

Here you can see the result:
https://www.astrobin.com/i7ezdq/K/




I was positively surprised that such a good result could be achieved despite the physical differences. The stars were not blended in, but the RGB information was processed into the luminance using LRGB in PI.  It was already clear in advance that the spikes would not contain any colour information, but in the end this prevented me from continuing with this setup. Beautiful starcolours and spikes with the coloured diffraction are too important to me, as here in the single-variety setup:

Messier 39 with G2-8300 + Newton 250/1000mm

• Luminance 8 * 300"
• RGB 5 * 300" each

https://www.astrobin.com/356817/K/


I hope this information helps you!

CS Daniel

Thank you @Dunk  and @astrodan for the insight. I just actually got a master file with 2.5hrs on the north american nebula.

Yes, the stars are not perfect, but to me it seems more like a problem with spacing and maybe some tilt. What do the experts think?

Without Bluxexterminator




With Blurexterminator:




Having dealt with a Samyang lens, these problems seems solveable, right?

Thanks for the help.

andrea tasselli:
I'd venture to say that it looks more  like a spacing issue rather than tilt, I can definitely see some field curvature there and not much tilt. What CC was used with the scope?

Yes, my thought exactly, too. And I guess the guy that is selling the scope just didnt realize that and was correcting collimation issues when there were also obviously some spacing issue. He replaced also the secondary mirror spiders etc.

I think it is the TS Superflat 1x corrector.