First light test shot with new 8" newt

[Garyh]

Hi everyone,
Has been awhile since I have posted any images as I have been busy getting the bugs out of my new setup. With lots of bad weather and only a little clear skies with mainly horrid seeing its taking longer than I first thought.
But I am getting close to doing a full imaging run as soon as weather permits..
Guiding is now very solid and all is tracking well even with the GM-8 loaded to capacity.....13.5kg total weight.
Replaced the Astigmatic secondary which was a real headache with a nice 1/8 Pyrex secondary, Thanks Phil.
Only one thing left to sort out now and that is I am getting some coma in the corners still with the MPCC...
Collimation looks good with the GSO collimator? so I am a bit stumped why it is still showing? the coma looks quiet even without the coma corrector..
Any advice on this would be very appreciated!..

Anyway here is a picture of new setup and a guided 4min shot of good old M42...Straight from the camera with nothing done other than resizing/converting for posting..
Seeing was a bit crappy but can`t do much about that..
cheers and thanks for looking!
Gary

[RB (Andrew)]

here is a picture of new setup and a guided 4min shot of good old M42...Straight from the camera with nothing done other than resizing/converting for posting

Wow Gary !
For a shot that's straight out of the camera that's terrific.
I've seen processed shots that don't even come close.

Onya mate, hope you sort out the corner coma issue and I'm hanging to see what you'll produce with the new setup in good conditions.

[Ric]

That's a great looking setup Gary, I reckon you'll produce some great images with that.

That's a great first light of M42 as well.

Cheers

[multiweb (Marc)]

Nice picture and nice rig. That's a lot on your GM8! I have a baader MPCC on my 5" newtonian. I do get a bit of coma still. I spaced the MPCC with the recommended 55mm from the CCD sensor but I've noticed that I get different star shapes in the corners still and it seems to depend on the filter I use on top of the MPCC too. So I guess depending on the light path and how many lenses you have to go through the distance slightly vary?

[rogerg (Roger)]

Nice pic of the setup and nice pic from the setup!

I've put a lot on to my GM8 in the past and it's handled it no problem, it doesn't surprise me that you can have what you have there on the GM8 and it still handle the situation. Mind you, I've had other issues with my GM8, but capacity hasn't been one

[AlexN]

Nice Gary, Very nice infact... single shot, straight out of the camera, that is brilliant.

Now, get 15 of them, stack them and post back!!

I'm keen to see what you can get out of your setup.


Alex.

[redsquash]

phenomanal

[Satchmo]

Is this full frame ? I can only see something coma-like in the bottom left hand corner whuch suggests something odd about the alignment of the MPCC ?

[Garyh]

Thanks everyone,..
Yes the GM-8 is still quiet sturdy with all the weight and I reckon it could handle some more! I tried to keep things as light as possible but still took it to the max!
Shall adjust the secondary mirror some more and see if it improves the coma.
Yeap the telescope is a collection of homemade, bits and pieces from IIS members and some other secondhand parts..
Only new part that was bought were the rings! Still cost maybe $600 all up.
cheers Gary

[AlexN]

Not considering selling the 6" F/5.6 any time soon are we??

Raises hand for first dibbs!!

[ozstockman (Mike)]

Gary,
I like your M42 more than mine. Considering that it's a single shot while mine is a stack of 9 yours looks much better,

P.S. I cannot see any serious coma problem at the corners you should worry about. It seems to be a great OTA.

cheers,

Mike

[Jen]

Very nice pic Gary nice looking gear you have too

[Deeno]

One 4 minute exposure!!!
Real potential in your new rig

[atalas]

One 4 minute shot ! impressive.

[dcalleja]

Its a nice looking setup Gary. You'd have to be happy with that rig.

[Kevnool (Kev)]

Impressive image and a Top shelf rig perfect combination....cheers Kev.

[Alchemy (Clive)]

finished at last, this is the 8 inch mirror you did yourself i take it ? the only suggestion for the coma is try to adjust the mpcc a couple mm either way and check the results.

if it is as good as the 6 inch for performance you have an outstanding setup. Will watch to see the results.

[Garyh]

Originally Posted by Satchmo

Is this full frame ? I can only see something coma-like in the bottom left hand corner whuch suggests something odd about the alignment of the MPCC ?

Full frame Mark, yes coma in the bottom corner but its a bit worse when I rotate the camera 90 degrees...Strange as the coma looks pretty concentric without the corrector? maybe it is the MPCC?

Originally Posted by AlexN

Not considering selling the 6" F/5.6 any time soon are we??

Raises hand for first dibbs!!

LoL yes might be up for sale shortly!
No focuser supplied but!
cheers

Originally Posted by Alchemy

finished at last, this is the 8 inch mirror you did yourself i take it ? the only suggestion for the coma is try to adjust the mpcc a couple mm either way and check the results.

if it is as good as the 6 inch for performance you have an outstanding setup. Will watch to see the results.

Thanks Clive, yes this is the 8" mirror I have made and I don`t think the figure is too bad on it.. Readings say nearly 1/12 PV but I think in real life it would be more 1/6 - 1/8 PV at best...
Tried your suggestion last night but can only pull it away a few mm and try it without much difference. I think If I can get it out 5mm it might help some? More experiments to come..

Thanks everyone for your comments and tips.
Much appreciated!...
cheers Gary

[AlexN]

cool it would require motor focus for me any way. Let me know when its for sale!

[jase (Jason)]

Whoa! No holding you back now Gary. For a "kick the tires" type image, I can't wait to see the new developments as you acquire more data. Enjoy the fruits of your labour.