NGC6188 widefield

[gregbradley]

I took this one a while ago.

I finished the processing of it today.

The lovely AP130GT with Quad TCC at F4.5 and QHY600M on a PME mount.

Ha S11 O111 RGB 90 60 60 12 12 12 minutes in narrowband mode on the camera.

https://pbase.com/image/172004719/large regular size

https://pbase.com/image/172004719/original large size go for a swim around.

Greg.

[The_bluester]

Nice, I did an image of the area recently but cropped out the dragons egg as it was too close to the edge in my framing so it was a distraction rather than adding to the image. I am wondering if the Oiii is stretched a bit too hard and making the fainter areas more noisy? And perhaps similar on the stars? not noisy as such but there are so many in the area, a lighter stretch on the RGB might make them a little less punchy?

Interesting factoid. There is a tiny little planetary nebula in there, in your image it is about three quarters left, three quarters down, a titchy red smudge below the triangle of bright stars. It is ESO 226-15. You have it more clearly in this image than I had in mine, it really only shows in my RGB image, in my RGB-HA-Oiii version it is nearly invisible. I saw it when trawling my RGB image for obvious defects and had to go hunting online to work out what it was.

[PKay]

Like it Greg.

Lots of detail to see.

Good one :thumbsup:

[gregbradley]

Thanks Paul. every image seems to have its challenges. Yeah there is a bit of fine noise in the O111 area but I don't mind it personally. I do like the stars as they are and its one of the strengths of the APO to produce such tiny stars so that must be a matter of taste.

I saw that little red spot as well. At first I wondered if it was an artifact and then looking again it looked real. Interesting.

[The_bluester]

I am personally not against lots of stars. One of the reasons I am tending at the moment to do RGB-NB images is so there are more stars in context than you generally see in an NB only image, as well as natural star colours.

It is interesting that your wider framing here brings so much more of a starfield to it than mine, which was not a much smaller FOV than yours.

[gregbradley]

Yeah some objects the Ha has a relatively definite border. I also used 120 second subs for the RGB stars and that seems to have been a good strategy as sometimes even just 5 minute subs can blow the colour somewhat in the stars.

Greg.

[The_bluester]

I suspect the star colours in my helix might have been slightly better with 2 or 2.5 minute subs, I was using 5 minutes which makes the stretch easier but each sub had several hundred saturated pixels, obviously the brightest bits of the brightest stars. If the weather improves I might try the RGB again using shorter subs to see if the colour of brighter stars improves.

[gregbradley]

Yes I think that would be a good strategy. I have been using 300 seconds for colour and sometimes that is too long. Fast optics and around 90% QE makes for rapid imaging.

Greg.

[graham.hobart]

That is a superb image Greg, I absolutely love it. It reminds me of a crested cockatoo. Bravo
Graz

[gregbradley]

Thanks Graham. I like the images I am getting out of the AP130/QHY600. The AP scope is living up to its reputation.

Greg.