Sword and Flame 180mm Leitz apo

[DaveS]

Added up some data from last night, together with data from a few nights ago.

30 mins each Luminance, 42 mins each HII, Red, Green, Blue in 60 sec subs. Heavily cropped to remove alignment edges due to having to align by eye and RDF HII added to Red, all stacking and post in AA5. DDP, two rounds of histogram stretch, and a further DDP.

I don't know where the Blue Bloat has come from, possibly the dodgy ZWO RGB filters, or perhaps the lens isn't quite as apo as I supposed. Next time I will do individual R, G, B captures and refocus between filters, rather than just going RGB, RGB etc.

Oh bother, the JPEG shows a residual edge that I hadn't spotted.

[DaveS]

Captured 42 mins of new Blue subs last night, plus a new set of 30 mins HII. Looking at the filter curves for the ZWO filters, the blue goes deeper than the Baader, possibly pushing the correction of the lens. Left the Luminance out, as I found it was captured with an Astronomik CLS-CCD rather than the ZWO IR-UV cut that I thought was in the wheel. Did a histo stretch before DDP this time.

What do people think? Better? At least I think I've got the blue bloat under control now.

[simmo39]

Looks better to me. V nice.

[DaveS]

Thanks Simmo

Not too sure about the red centre, not convinced it's really HII, maybe residual vignetting. I'll try and get some twilight flats this evening.