PDA

View Full Version here: : M75 GSO 10" f/4 first *corrected* light


furgle
11-09-2017, 12:52 PM
Messier 75 is a dense globular cluster 65000 light years away. This test shot is the first published photo from my new 10" f/4 Newtonian telescope, and it's been quite a journey to get a nice field corrected image from it. Now I wait for the new moon and a suitable target.

**Image:**
* 25x 120s Light pollution filter as luminance
* 12 : 12 : 13 x 120s R : G : B
Total exposure 2 hours 4 minutes.

**Hardware:**
* GSO 10" f/4 newtonian
* SkyWatcher EQ8 Pro Mount
* QSI 683-ws8 Camera @ -15°C
* Teleview Paracorr II field flattener
* Astronomik Typ2 LP & RGB filters
* Starlight Xpress Lodestar X2 Autoguider
* Starlight Instruments Focus Boss II

**Location:**
* Orange zone in Brisbane, Australia. (Bortle 7)
* Imaged during full moon.

Better resolution here (http://adam.lundie.com.au/astrophotography/Messier_75_Globular_Cluster/Messier_75_Globular_Cluster_2017091 0.html)

strongmanmike
11-09-2017, 12:59 PM
That's a small image to critically judge by but...looks pretty good :thumbsup: glad you sound like you have everything working satisfactorily...that's a capable setup you have Adam, so bring on the new Moon! :2thumbs:

Mike

Placidus
11-09-2017, 03:49 PM
Success! Field looks very well corrected. Colours are nice too.

Flugel88
12-09-2017, 11:54 AM
Looking good mate.
Field looks flat stars looking coma free from what i can see.
Dark point looks nice free from gradient problems.
I like how you break down your image processes on your website under software used.

peter_4059
12-09-2017, 06:10 PM
Hi Adam

I see on your website you have AO. Are you using that with the QSI?

Nice flat field in your image.

Peter

furgle
12-09-2017, 06:27 PM
Eventually I would like to, but I'd need to work out what adapters I'd need to make it fit the imaging train. Right now I only use it one my 11" c11 edge.

There's also a the matter of finding enough that inward focus, and making sure the focuser tube doesn't appear as a shadow in the image.

Paul Haese
13-09-2017, 02:51 PM
Looks not bad Adam (I like the colour), but agree with Mike that it is a little hard to assess with the current size on your site.

How did you go with tilt on the paracorr? I have found the GPU quite difficult to sort out and there is still a bit more to address. Which focuser did you go with? The Moonlite I bought has a little slop in it too which is not helping.

furgle
13-09-2017, 05:28 PM
Due to the weight of the camera & paracorr I have some issues with tilt, especially at the meridian. I also had to rotate the secondary cage so the camera is under slung due to all the extra counterweights I had to put all over the scope. I have a 24" dovetail on the way so hopefully I can move the scope back a bit further to remove some more counterweights.

I also have a hella expensive Gerd Neumann Camera Tilting Unit but I don't have the right adapters to fit it in to my imaging train yet. I used them all just to get the paracorr spacing right.

For focusing I use a feathertouch posi drive. Very happy with it since it has no discernible backlash so far.

This thing has been a major pain in the ass. Don't chase aperture! I just hope it's all worth it in the end.

furgle
13-09-2017, 07:19 PM
The setup with all the counterweights :/

multiweb
14-09-2017, 07:40 AM
Nice scope. Looks like you've got that field sorted out. :thumbsup: