NGC6723 in Corona Australis - a scope comparison

[cometcatcher]

I've seen some pretty spectacular images of this region on the forum, mine ain't one of them. :lol: However I thought I would post these two comparison images for a bit of fun. This is a comparison of a 6 inch F5 Newtonian to my new Skywatcher ED100 F9 refractor. Kind of like comparing apples to oranges, but then that's the point. ;)

There's a little globular cluster (NGC6723) some blue reflection nebula and dark nebula in this region. Here I have just short of half an hour for each scope, both with 1 minute subs at ISO 1600 on the Pentax K-x. For a shot I would be happy with, I'm thinking about 5 to 10 hours would make for a nice end result. Yeah like that's ever going to happen here in the tropics. :rolleyes: There is some mirror flex on the Newt, looks like I will either have to redesign the mirror cell or use shorter subs. I'm surprised the refractor is nearly able to keep up, but the F5 Newt is definitely in the lead, but not by that much.

What do you guys reckon?

[raymo]

The bright objects are pretty much the same, but if you flick back and forth between them, you will see that there are far more stars visible
in the 6" pic, which is to be expected.
raymo

[kosh]

Interesting stuff Kevin.

I actually find to my eye that the globular seems sharper, and better resolved in the ED100, but that is just me. Although, you can tell (just) that there is a bit more data in the newts subs.

Goran.

[raymo]

You are right Goran; I hadn't noticed; probably too busy looking at the stars. You can see individual stars resolved in the globular.
raymo

[cometcatcher]

The better tracking with the refractor may help resolve the stars better, and the longer focal length too even though the 6" goes deeper.

I can't imagine doing 10 hour total time with 30 second subs though. That would kill a DSLR after a few DSO's. Even 1 minute subs are a bit short. But then, I need a new camera anyway. May as well wear out what I've got first.