M83

[Jon]

Here's another M83. 5 hours total data (150:50:50:50) from the suburbs in Canberra, Atrik 383L+ on the Meade 10" SCT at f/6.3.

Full resolution image here (http://astrob.in/88166/0/)

Cheers

Jonathan

[atalas]

Nice work Jonathan.

[strongmanmike]

That's an excellent M83 Jon, you have structure showing in the two small galaxies on the right and you can make out the faint arm that reaches out to them below M83, a very good result, you must be happy with that :thumbsup: I like M83 presented at this orientation too ;)

Mike

[alpal]

Hi Jonathan,
That's a great M83 with lots of detail.
I hope you don't mind - I made some small changes?
The core has been sharpened slightly & I've
worked on the stars to make them smaller, softer & increased their colour.
Do you like that better?

cheers
Allan

[Jon]

Hi Alan,

Yes, that's great! How did you sharpen the core to make it clearer but not harsh?

Cheers

Jonathan

[alpal]

Hi Jonathon,
I am glad you like those small changes.
The core was the easy part.
I sharpened the whole picture at about 2 pixels on another layer.
I then placed a hide all mask on it. (black)
I then used the brush to paint over the core in the areas
I wanted sharpened using white on the mask but painting on the pic.
I then blurred the mask at about 12 pixels & adjusted opacity to suit.

cheers
Allan

[Jon]

Ah, ok. Sharpen at a small value then blur again at a lager value. I can see how that brings out detail but prevents the harshness I get with sharpening on its own.

Now, making the stars smaller and softer ... Tell me about thst one. Whenever I've tried it it's left rings around the stars.

[Astroman]

Very nice work Jonathan, and nice processing Allan.

[alpal]

Hi Jonathon & thanks Andrew,
That's much harder & from memory:

New layer
Select colour range highlights.
Select modify - expand by 4 pixels -feather by 2 pixels.
Alt lasso to deselect the galaxy.
Ctrl M to get curves.
Ctrl H to hide.
Adjust right had side much lower.
Left hand side close to center line but slightly lower.
That will make the stars smaller.
Blur by 2 to 3 pixels - that will stop rings & soften the stars.

Flatten.
New layer
Reselect stars
Switch to LAB mode.
Increase colour with a & b sliders to equal values.
Place a show all mask on & then paint over some stars with black
to stop the brighter ones getting too much colour.
Adjust opacity.

Flatten & switch back to RGB mode.


I hope that helps?

I think I need to make some videos to add to Louie's ones here:

https://www.youtube.com/channel/UCJ5b6pFHBGe66vsuSaXb-0A

All of that comes from variations of Louie's work.

cheers
Allan

[Rigel003]

Very nice image, Jonathon. Good detail and nice colour differentiation between the blue arms, pink HII regions, and yellow core. Interestingly the astrobin site lists a wealth of detail for every aspect of the image train and capture parameters but no mention of the scope used.

[Jon]

Really? I'll fix that. It is a Meade 10" SCT classic with an f/6.3 focal reducer. Perhaps not the ideal scope for this sort of stuff, but I mainly use it for photometry and spectra these days, at which it performs well. I still like to grab the odd pretty picture on clear moonless nights :-)