Standing on The Edge of the Lagoon

[dylan_odonnell (Dylan)]

I'm quite surprised at how well this turned out for a mere 35 minutes (7 subs) of data. It's a nice bright target like that, but I was even shooting at F10 with the full focal length of my c9.25 EdgeHD SCT (2350mm).

The coma in the corners bothers me a lot and I did notice some drift even though my tracking was perfect and locked on steady, so I believe I have some flexure between the OTA and the guidescope. I'm hoping an OAG helps that somewhat.. the field should be flatter than this with the Edge HD series shouldn't it?

Taken with QHY12 OSC CCD and processing in Pixinsight and Photoshop.

[g__day (Matthew)]

Beautiful - really has atmospheric effect on the viewer!

[Ryderscope (Rodney)]

Nice detail in the nebulosity Dylan. There is some small elongation of stars in the corners that may be due to the camera not sitting square. Still a beautiful shot with nice detail and colour. Thanks for sharing.

[pluto (Hugh)]

Very nice!
Love the colours

[dylan_odonnell (Dylan)]

Originally Posted by Ryderscope

Nice detail in the nebulosity Dylan. There is some small elongation of stars in the corners that may be due to the camera not sitting square. Still a beautiful shot with nice detail and colour. Thanks for sharing.

Thanks guys! If the camera wasn't sitting square wouldn't the elongation be in one or two corners? It seems to be in all four.

[Ryderscope (Rodney)]

Originally Posted by dylan_odonnell

If the camera wasn't sitting square wouldn't the elongation be in one or two corners? It seems to be in all four.

Hmmm - good point. Wouldn't be tracking though me thinks given the direction the stars are pointing.

[RickS (Rick)]

Nice colours and I like the "transparent" look.

[DJScotty (Scott)]

I like the colours too. Very atmospheric

My 5 cents is it is coma. Don't know a lot about the OTA you are using but the camera appears to be slightly off centre and/or tilted. That would explain the stars pointing in towards the centre.

But very nice image

[Ken]

Nice image shame about the coma, these scts have a very good corrected field with a corrector in the baffle tube. I believe Celestron have a long adapter to space the camera too the proper distance, at a guess the camera is too far forward.
Clear skies Ken.

[dylan_odonnell (Dylan)]

Originally Posted by Ken

Nice image shame about the coma, these scts have a very good corrected field with a corrector in the baffle tube. I believe Celestron have a long adapter to space the camera too the proper distance, at a guess the camera is too far forward.
Clear skies Ken.

Ah ha.. now that makes more sense to me. The CCD is bang on the rear cell with the T-adapter.. there's nothing else in the train so I can't more it closer but I could use a spacer to put it further back. I'll give that a shot next time, thanks!

The Edge HD OTA has been really great with the Hyperstar lens at the front. Field is flat as a pancake. It's just shooting at the rear cell it's cropped up for me.