Centaurus A now with colour repro and added time

[gregbradley]

I got quite a bit of colour and some Ha for the luminance I posted.
32 x 5 minutes gain 53, -10C blue
23 x 5 mins red, 22 x 5mins green, 12 x 5 minutes Ha

The camera is very sensitive and very low noise.

I got more exposure time last night. I added this to the image plus reprocessed it from scratch using flats as well.

It looks a little yellowish but I believe that is the correct colour as the data wants to go that way and also elliptical galaxies are often yellowish.
The image is also starting to show a hint of the shell structure and some odd shaped extended star halos at both ends.

Same links:


https://pbase.com/image/170640292/large regular size

https://pbase.com/image/170640292/original very large size

I think this makes the Honders a galaxy imaging machine.

Greg.

[Camelopardalis (Dunk)]

What's not to love about high QE, lots of tiny pixels and fast f-ratio?!?

[gregbradley]

Originally Posted by Camelopardalis

What's not to love about high QE, lots of tiny pixels and fast f-ratio?!?

Yes its a pretty ideal combo. Focusing though seems to be a lot harder. Less so now that it should close to focused when I turn everything on.

Greg.

[topheart]

Well done Greg!!
What's the critical focus zone for the setup with the Honders?
Cheers,
Tim

[gregbradley]

Originally Posted by topheart

Well done Greg!!
What's the critical focus zone for the setup with the Honders?
Cheers,
Tim

Thanks Tim.
With an Atlas focuser and a 9 micron pixel camera usually I get it to within .2% of the travel of the focuser which is 10mm.
Not sure what it is with the smaller pixels, perhaps nearly 1/4 of that.

Greg.

[Placidus (Mike and Trish)]

Superb!

[Atmos (Colin)]

My RH200 has a CFZ around 30 microns under my usual seeing being an 8" F/3.

Your Honders is a 12" F/3.8?
That should have a CFZ around 75 microns under 2" seeing.

You have captured some pretty nice detail too btw

[gregbradley]

Originally Posted by Placidus

Superb!

Thanks M and T.

Originally Posted by Atmos

My RH200 has a CFZ around 30 microns under my usual seeing being an 8" F/3.

Your Honders is a 12" F/3.8?
That should have a CFZ around 75 microns under 2" seeing.

You have captured some pretty nice detail too btw

Thanks Colin. The CFZ is pretty tight. I used @focus 2 (in the Sky X) tonight and it
worked quite well.

Greg.

[Atmos (Colin)]

I’ve heard @focus3 is a significant improvement, I haven’t used it myself though. I find FocusMax to be really good once calibrated.

[gregbradley]

Originally Posted by Camelopardalis

What's not to love about high QE, lots of tiny pixels and fast f-ratio?!?

Originally Posted by Atmos

I’ve heard @focus3 is a significant improvement, I haven’t used it myself though. I find FocusMax to be really good once calibrated.

Thanks Colin. I'll see if I can get @focus3 otherwise I'll try FocusMax again.

Greg.

[multiweb (Marc)]

That looks excellent Greg. Nice image scale with that combo.

[gregbradley]

Originally Posted by multiweb

That looks excellent Greg. Nice image scale with that combo.

Thanks Marc. Still learning how to get the best out of this camera.

Good imaging weather this week eh?

Greg.

[Phil Hart]

Impressive scale and detail for sure Greg - you would be happy with that setup. I reckon this online version has ended up a little black-clipped. You might be able share a bit more detail with us than what's in that version?

Phil

[gregbradley]

Originally Posted by philiphart

Impressive scale and detail for sure Greg - you would be happy with that setup. I reckon this online version has ended up a little black-clipped. You might be able share a bit more detail with us than what's in that version?

Phil

Yes I see what you are referring to. I'll do a repro on this one.

I might use flats on this as well as whilst there was no appreciable vignetting there was a slight reddish gradient that I tried to remove and probably black clipped a little there. Thanks for the suggestion.

Greg.

[Retrograde (Pete)]

Looks great already Greg. Will be interested to see the reprocess.

[gregbradley]

Originally Posted by Retrograde

Looks great already Greg. Will be interested to see the reprocess.

I think I will use some flats and see what they look like. Perhaps some background Pixinsight magic.

Greg

[gregbradley]

I added some extra exposures I took last night and reprocessed it from scratch and used flats.

https://pbase.com/image/170640292/large

Greg.

[peter_4059 (Peter)]

The galaxy details are amazing but there is something about the large stars that doesn't look quite right to me - perhaps it's my monitor or failing eyesight

[codemonkey (Lee)]

Lovely colour and contrast, Greg! Well done.

I do agree with Peter though, the stars look a bit funky. Looks a bit like something I see on stars when I use too much decon?

[gregbradley]

Originally Posted by peter_4059

The galaxy details are amazing but there is something about the large stars that doesn't look quite right to me - perhaps it's my monitor or failing eyesight

Thanks. I think I have corrected the halo effect around brighter stars. I was so concentrated on the centre details I didn't really check the brighter stars. Thanks.

Originally Posted by codemonkey

Lovely colour and contrast, Greg! Well done.

I do agree with Peter though, the stars look a bit funky. Looks a bit like something I see on stars when I use too much decon?

No a bit of an artefact entered in. Corrected now.

If I get another clear night tomorrow I might add even more exposure or start combining with earlier data.

Greg.