M33, imaged with an achro through LP and murk...

[Amaranthus (Barry)]

M33 is a classic northern hemisphere DSO. However, I thought I'd take a challenge and capture it low on the horizon from the south (it never rose above 22 degrees altitude). There was also substantial light pollution and a hazy atmosphere to peer through, and it was imaged through an achromat (at f/4), which meant that it was impossible to gather focused Luminance frames (so the Lum was synthetic, based on a weighted blend of the R, G and B channels and Ha data).

The overall result is not great (the R and B channels bloat badly with the achromat - this is really only good as a narrowband astrograph), but at least I can say I tried!

Ha = 16 x 900 sec
R = 48 x 100 sec
G = 44 x 114 sec
B = 47 x 92 sec

(RGB sub-length determined for optimal colour balance). Ha-R was used for the R chrominance channel. Post-processed using Startools.

For now, I think I'll keep the achromat for exclusively NB imaging!

Full capture details and higher rez images here:
http://www.astrobin.com/126583/B/

[RickS (Rick)]

Definitely a serious challenge you took on there, Barry! And you got something of a result

[LightningNZ (Cam)]

Very impressive considering you had the odds stacked against you. Well done!

[cometcatcher (Kevin)]

It's not too bad for an achro. Was the ED80 too slow for the task at F6 with the reducer?

[Amaranthus (Barry)]

Thanks Rick, Cam and Kevin for the feedback!

Kevin, funny, the ED80T was packed up already for the move to Tassie, so I made do with what I had. (The ED80T with the 0.8 reducer is still quite fast, at f/4.8)

I wanted a last shot of M33 from Adelaide, before it vanished below my northern horizon forever. I'm now at Lat 43S in beautiful dark skies (Bortle 2 rating), but waiting for my gear to arrive But M33, and anything more northerly than about DEC +30 is forever hidden (there are some trees and hills that block the far northern skies). Still, everything else is going to be glorious...

[Camelopardalis (Dunk)]

Nice one Barry lots of colour in there and the spiral arms are nicely pronounced.

Good luck with the move, maybe you'll join us up on the mainland for some more subs some day?

[atalas]

Good effort Barry.

[Ross G]

Hi Barry,

Another nice capture.

A good memory to have before you migrate south!

Good luck.

Ross.

[Amaranthus (Barry)]

Thanks Dunk, Louie, Ross.

I'm all done with imaging in light-polluted skies - goodbye and good riddance... The only form of LP I now have to cope with is moonlight, gegenschein and aurora!