The Rosette again

[RobertM]

Star were a little out of focus and there's a touch of quiffy stars in the corners so will have another try sometime soon.

Sub exposures: 25 x 300s
Filter: Baader UHC-L Luminance booster
Scope: Hyperstar C11
Camera: Starlight-Xpress SXVF-M25C
Sky - not great
Captured in MaximDL
Processed in PixInsight



Link to larger version: http://farm9.staticflickr.com/8061/8204489406_a8fa056429_o.jpg

[Carole]

That's looking really nice Robert.  Is that a one shot camera Robert?  I googled it but couldn;t find the exact model.

Carole

[Ivor]

Great shoot I do like this target, and I'm very jealous as I can only cover half the target in my scope.

[RobertM]

Thanks Carole and Ivor.  Yes Carole it is a one shot colour.  There is a slightly updated version called the SXVR-M25C being made now.

Robert

[MarkS]

Presumably you imaged that from home?

If so, that really is a good result from such a light polluted location!

Mark

[RobertM]

Thanks Mark and yes it's from home. I could have made more of it if the stars were in focus as that also seems to affect star shapes in the corners.  I'm trying to process an M33 but that has worse gradients, even with 'proper' flats it's a real mare.

Robert

[MarkS]

I'm trying to process an M33 but that has worse gradients, even with 'proper' flats it's a real mare.

Robert

I know the problem.

Whenever you have background light pollution, you end up with gradients that are horrible to remove (even when you have a good flat).  It also seems to me that the more complex the optical system, the more complex the structure of the gradients and the more difficult they are to remove.  How I loved the ED80 - nice simple optics!

[RobertM]

I agree, you can certainly understand why refractors are so popular though think that a refractor image of this would have been equally problematic.  My next attempt will involve calibrating and attempting to remove the gradient from each sub individually prior to stacking.  the reason is that I reckon the gradient moves radially around the image as the telescope tracks making removal difficult.

Robert

[MarkS]

My next attempt will involve calibrating and attempting to remove the gradient from each sub individually prior to stacking.  the reason is that I reckon the gradient moves radially around the image as the telescope tracks making removal difficult.

I have already started to do this - gradient removal per sub.  It makes a noticeable difference to the final stack.  Part of the problem with gradient is that the imaging target moves across the sky and the gradients are different in each part of the sky.

Mark

[RobertM]

That's good news.  If you've already had success then that bodes well for my attempt.

Robert

[JohnP]

Very nice result Robert - I'd be haps with that especially from Bromley. John

[Fay]

That is extremely nice Robert. Made me do a reprocess of one of mine, adding colour to mono. will post later

[MarkS]

That is extremely nice Robert.

Yes, sorry I pipped it with my Jupiter for image of the month 

[RobertM]

No worries, there's always next month