Harrys cocoon

[Harryianpage]

Hi
Have not posted a image here before , so I thought I would give you something to abuse ( go on houghy you know you want to )

This was taken with my 14" newt and a new keller reducer , which I have not got set up right yet

1) 14" newt at f3.75
2) rgb with osc sxvfm25 ( 250 mins )
3) lum with sxvf h16 ( 420 mins )
4) all 10 min subs

and of course processed in Pixinsight

High res version at http://www.harrysastroshed.com/Image%20html/Cocoon.html

I am not happy with the star shapes , but are happy with the depth for a short exsposure time


Regards harry

[h0ughy (David)]

looks a lovely image Harry. a 14" f3.75 !!!

my picks - the nebulousity and colours - look great (but i have not seen this object before ) and the dust
my pick on's - you have noise in the form of random blue pixels throughout? and it looks like you have pinched optics with the stars resembling folded triangles?

[Harryianpage]

Originally Posted by h0ughy

looks a lovely image Harry. a 14" f3.75 !!!

my picks - the nebulousity and colours - look great (but i have not seen this object before ) and the dust
my pick on's - you have noise in the form of random blue pixels throughout? and it looks like you have pinched optics with the stars resembling folded triangles?

Hi

Yes there are a few colour hot pixels I need to get rid of
The bad shapped stars are due to the very fussy keller reducer and some optics shift from trying not to pinch the optics
Got to be some happy medium somewhere

Harry

[alan meehan (Alan)]

Nice image Harry the cocoon has a very dense neb cloud i like it and as houghy said have not seen this before
Thanks ALAN

[richardo (Rich)]

Hi Harry,
good to see you post here!

Nice rendition of the Cocoon Neb!

I see what you mean with the stars..

Nice hunk of glass Harry, I guess with experimentation with distance you'll find the sweet spot. All takes time.

How's you colimation? Hope your using a auto collimator! So touchy at these fast F ratios.
But I know you're aware of this.

How have you fixed your primary?? Clips, sling?
Silicone works really well and will eliminate dramas with pinching. Just a thought.

Wow, love your setup.... yes, the mount and scope together certainly is a 'beast'

Good luck with sorting your little issues out... look forward to more.

All the best
Rich

[RobF (Rob)]

Yes, thanks for posting here to show us Harry.
We'd love to follow your progress with the Keller corrector with interest.

Plenty detail and lovely soft overall appearance. I love the star colours you've got there even if you think you can do better. Sounds like a great scope set up.

[Harryianpage]

Hi People

Thanks for looking and taking the time to reply , always very welcome

And as for the idea about using silicone on the primary , not thought of this , do you just silicone the edge supports ? so I can then release the clips a bit


Harry

[richardo (Rich)]

Originally Posted by Harryianpage

And as for the idea about using silicone on the primary , not thought of this , do you just silicone the edge supports ? so I can then release the clips a bit

Harry

Hi Harry,
I guess your primary cell is a floating 9 point or 6 arrangement?? Usually the case for a 12.5" flat mirror.
If so, totally get rid of the side supports (hack saw them off).... and place a dob of neutral cure/ non acidic silicone to each of the 9 support plates/ points. Also when pushing the mirror down on the supports with the dobs of silicone, it pays to have very thin (1mm or there abouts), tiny plastic washers (5mm dia or there abouts) as spacers.. or you could use small nails and remove them after the silicone cures.... this is so when you press the mirror down the little washers/ nails act as spacers so you get a uniform gap. Need this gap as it adds to help cool down.
Leave to cure for 24- 48 hours.

If you still want to leave the side supports on, leave a small space between the edge of the mirror and the side support then add a dob of silicone on each.

Really, the side supports would be over kill imo. Silicone has very strong adhesive properties... many have done this with no dramas.

Here's a step by step view although in french, the pictures tell the story.... hit the arrow to go to next page
http://www.reto.fr/t350/imagepages/image44.html

Here's another link
http://www.scopemaking.net/dobson/finish.htm


Hope this helps.

Rich

[Harryianpage]

Hi

Well I have been glued the mirror down with silicone

So if it all goes wrong its your fault


I will let you how I get on , thanks for the idea


Harry