Iris Nebula - issue with bloated blue stars

[Martin-Devon]

Managed to complete the RGB last night to add to the L data I got last weekend. Total now of 31 x 10 min subs L, and 6 x 10 min subs each for RGB, all unbinned. During the processing in photoshop I seem to have several bloated blue stars, this is especially noticeable on the larger ones - any tips from anybody on how to reduce these?

Thanks for looking....

[davy999]

Providing the guiding was spot on you may be saturating the wells of the chip, which can cause bloated stars. Chip saturation occurs at 65535 when you check pixel value. Maybe the 10 minute Lumi. subs were too long and the stars were very bloated because of that.

Best thing to do is to check the subs of all colours and if only certain ones show bloated stars it may be saturation of that particular wavelength of light over a 10 minute exposure?

Or, I could be totally wrong, just a thought!

[Mark72]

It's not a great deal to reduce them with a minimum filter. In PixInsight there is also a script (Masked Stretch) to prevent them form growing in the first place.

SC telescopes normally have fatter stars.

Mark

[ollypenrice]

Big circular selection, well feathered, around the star and then hidden (Ctrl H).

Alt click on the background sky just outside the bloat halo. This pins the background as it is.

Just above the pin drop the curve than restore it higher up.

Repeat as necessary and adjust colour balance if it has drifted.

Where possible it can be a good idea not to apply L to stars, though for those embedded in nebulosity it can be hard or impossible.

This kind of object might respond to RGB only. My own Iris was with our OSC camera.

I would certainly avoid trying to do the image in a single stretch. I'd do a stretch for the dusty faint stuff and a new stretch looking only at the core. Then I'd layer them together. I'd also noise reduce the dusty layer and sharpen the core layer.

Olly

[Martin-Devon]

Thanks to everybody for feedback. Olly your post especially looks like something I can try so I'll have a go at the steps you suggest.

[Gina]

That's a lovely image, Martin

I see you live in Cullompton - I live just outside Upottery, not so far away

[Black Knight]

Definitely is a great looking image. I shall have to file away Olly's suggestion for easy recall as well

Sent from my mobile using Tapatalk, so please excuse the speeling and granma!

[AndyUK]

Definitely is a great looking image. I shall have to file away Olly's suggestion for easy recall as well

I'm now accruing quite a collection myself! (Thanks Olly!)

Martin - Very nice indeed... and you've certainly got a nice lot of dust showing! Looking at your image, I'm beginning to think I might have made an error with my exposure selection for this.... Although I got 10 mins luminance, I plumped for only 240s for RGB, but I've struggled to get any of good quality owing to the poor transparency over the last few nights . (Oh well - I guess I might be able to use them for core data... )