M7 Ptolemy’s Cluster ( Star test new 8” f5 KH Carbon fibre Newt )

[Startrek (Martin)]

Finished building my new carbon fibre newt last week with last night presenting a clear night with good seeing ( late dew not so good ) to test the optics.
The scope wouldn’t come to focus due to the TSGPU coma corrector changing the focus plane by around 20mm. I had an old Bintel 2” x 35mm eye piece extender so cut the nose off it , filed it flat and level ( checked with digital calliper) it did the trick , not pretty but effective.
Spider vanes were adjusted to within 0.40mm of each other , again using the digital calliper which has accuracy of 2 decimal points.
Scope was rebalanced, re collimated and set up a new profile for PHD2 ( new dark library, new calibration which I auto restored)
Chose M7 Ptolemy’s Cluster as a test target but had no idea that its background Star field was so bloody dense. The last time I imaged it was with a DSLR about 5 years ago and didn’t have the capability of my current 2600MC , wow what a Star field.

Captured 55 x 30 sec subs
40 x Flats
60 x Bias
Image calibrated out well
PHD2 Multistar guiding was running beautifully at 0.50 to 0.60 arc sec total )
Stacked in DSS
Processed in Startools V1.8 OSC linear data set

Pretty happy for a first light and Star test on this new 8” Carbon fibre Newt , stars in on axis region are round and tight , only some coma evident in the corner areas which I will adjust and re test using some 0.50mm shims hopefully tonight as rain is imminent.

Astrobin link below for more detail and better resolution ……

https://www.astrobin.com/aihe3n/

Original frame version ( 200KB )
Crop version (200KB)

Comments welcome

Thanks
Martin

[Dave882 (David)]

Wow Martin that’s an incredible image! And with the moon up whats even more impressive is the good colour and flat background. A gobsmacking starfield - simply jaw dropping yet very well resolved. Your attention to detail is really showing through in your images. Great first light!!

[AstroViking (Steve)]

Holy cow... That's a lot of stars.

Beautiful image, Martin.

[strongmanmike (Michael)]

Scope looks like a keeper Martone!

Fabulous field this, looks great, millions of stars! Just out of interest though, do you have version with less shrunk main stars? In such a scene I recon bigger and less worked on, stars, do look good, kinda accentuates/showcases the cluster more then, just a thought to try..?

Mike

[Startrek (Martin)]

Thanks Dave, Steve and Mike,
Much appreciated
Yep pretty happy with the bigger scope , still some spacing issues with my CC to sort out. This 8” carbon fibre newt only weighed 1.5kg heavier than my old 6” metal tube newt which does help. Light weight , strong and no flexure
Guiding has been brilliant with just over 2 runs , 0.45 to 0.60 total , spent time on balancing too.
So far so good and nice looking rig too
Mike, I applied SV Decon at default values which tightened up everything, could have backed off a bit , but I’m tragic for tight stars , always have been , don’t like soft stars (sorry if I offended the refractor folk )

Cheers
Martin

[strongmanmike (Michael)]

Originally Posted by Startrek

don’t like soft stars (sorry if I offended the refractor folk )

...or SCT

You wouldn't be a Newt'aphile...would you?

Mike