Star bloat with 294mc pro

[AstroNebulee]

6 hours ago, Budgie1 said:

I've just noticed the field flattener you're using, is it a Stella Mira FF?

If it is,  I got one so I could use it with my Evostar 100ED DS Pro to allow me to use the full 900mm focal length and I never get good sharp images with it. I tried it once with my 80ED DS Pro and that was the same, so I now only use the SkyWatcher 0.85 RF/FF for each scope.

It may be worth trying an imaging session on a target you've previously imaged with the FF, only try it without the FF to see if there's any difference with the star bloating. You won't get the flat field but concentrate on the centre of the image and see if there's an improvement or not.

It's the ovl FF so basically the same as the Stella mira one. 

I will try it without the FF at some stage when I get clear skies and especially at weekends with it dark so late and work early in mornings. 

I did try a dedicated sw FF before but couldn't achieve focus with it as not enough inward travel. This is because my 72ed is the slightly older 'long' tube version. So I'm stuck as regards to FF. 

Edited April 20, 2022 by AstroNebulee
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[ollypenrice]

10 hours ago, AstroNebulee said:

So am I correct in thinking, say I use the remove blue/purple halo action tool in a new layer (as I normally do) then I can reduce the opacity to actually bring some of the blue/purple fringing back in to try to offset some of the hard grey halo left behind? Excuse if I sound like a doofus. 

Yes, that's it. A refinement I'd be inclined to try would be doing the blue-purple halo reduction to a bottom copy layer and then activating the top layer and a feathered, bloat-sized eraser set to a partial opacity - say 50% - which I'd apply over the stars in question. You could then increase or decrease that opacity in the light of experience or use repeat iterations at 50%. This would guarantee that your bloat reduction be strictly limited to the stars you wish to alter.

I make endless use of layers and opacity in Photoshop to select where, and by how much, to apply a modification.  The opacity can be adjusted in several ways. 1) The global opacity of the upper layer using the layers palette slider. 2) The opacity of the eraser used to remove an unmodified top layer. 3) The Edit-Fade Eraser slider on the toolbar.  A friend once said that she expected my processing to be very complicated but that all I ever did was 'use the bloody eraser!'  Quite a lot of truth in that!

Olly

[AstroNebulee]

4 hours ago, ollypenrice said:

Yes, that's it. A refinement I'd be inclined to try would be doing the blue-purple halo reduction to a bottom copy layer and then activating the top layer and a feathered, bloat-sized eraser set to a partial opacity - say 50% - which I'd apply over the stars in question. You could then increase or decrease that opacity in the light of experience or use repeat iterations at 50%. This would guarantee that your bloat reduction be strictly limited to the stars you wish to alter.

I make endless use of layers and opacity in Photoshop to select where, and by how much, to apply a modification.  The opacity can be adjusted in several ways. 1) The global opacity of the upper layer using the layers palette slider. 2) The opacity of the eraser used to remove an unmodified top layer. 3) The Edit-Fade Eraser slider on the toolbar.  A friend once said that she expected my processing to be very complicated but that all I ever did was 'use the bloody eraser!'  Quite a lot of truth in that!

Olly

Thank you Olly, lots to go on there and try out on my processing. The eraser is something I've never used before in my processing workflow. 

Cheers 

Lee 

[scotty38]

On 19/04/2022 at 22:00, AstroNebulee said:

Thank you, the L3 seems to be the one for my set up as suggested👍

Also so it doesn't matter that my 2 inch filter is where it is in my imaging train eg scope - rotator with filter screwed in - FF - extension tubes - 294mc pro combined with tilt adjuster? 

Apologies for going OT here but what is the tilt adjuster you have there?

[AstroNebulee]

4 hours ago, scotty38 said:

Apologies for going OT here but what is the tilt adjuster you have there?

No problems, it's the zwo tilt adjuster bought from FLO 

https://www.firstlightoptics.com/zwo-accessories/zwo-t2-camera-tilt-adjuster-ii.html

Cheers 

Lee 

[scotty38]

35 minutes ago, AstroNebulee said:

No problems, it's the zwo tilt adjuster bought from FLO 

https://www.firstlightoptics.com/zwo-accessories/zwo-t2-camera-tilt-adjuster-ii.html

Cheers 

Lee 

Brilliant, thank you I didn't realise that was available....

[AstroNebulee]

Hi

I've been hard at work trying to take on board your suggestions and trying to bumble some sort of consistent workflow for my astrophotography processing and believe I've made sone progress today. Just using the new graxpert gradient software on my linear data then just processing in photoshop cs4, using starnett 2 to stretch the starless version and pasting and merging back in ps. I'm really pleased with how this looks compared to earlier processes. 

Just finalising the workflow now so I know it well. The blue channel has all the bloat so will figure out how to sort that. I'm fighting the bloat with my zwo ir uv cut filter until I've enough money for the L3. 

Hopefully you can see the improvement. 

Cheers 

Lee 

 

Edited May 1, 2022 by AstroNebulee
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