7 panel Mosaic of Eta Carina Nebula in Narrowband.

a few numbers...

1 Massive Nebula

2 Telescopes

3 Attempts to get this right

4 Months data collection

5 Days processing

6 Filters

7 Apps

8 Gb file

15min subs

16 Gig of Ram barely copes

250 + NB subs

270 RGB subs

42 Data sets

80+ hrs data

188,000+ stars

several dozen drinks!

My most ambitious project to date - NGC 3372 - Eta Carina in Narrowband with RGB stars.

Taken in it's entirety to give context of where it begins & ends in space.

This project began six months ago when I thought it would be pretty cool to get the whole nebula. Three attempts later, it ultimately it took 6 panels to get it all in frame, very tricky object to balance and compose with asymetric elements - Gabrielle Mistral/gem cluster at one end and the smoking man at the other, so I've kept the core pretty close to the centre so the other bits can radiate outwards.

I also wanted more resolution in the core, so I brought out my William Optics FLT 110 to get more detail there.

Took forever to get all the data, and Melbourne's inclement weather didn't co-operate oftenso some were taken under a full moon, resulting in a trip to gradient city with the RGB & O3!

Totally a processing challenge, but perseverance and sheer force of will kept me going though, not sure I'd recommend attempting this for the feint hearted.

Registar is incredible, worth every penny of the US$250 odd I paid - it registered over 188,000 stars! Gobsmakkingly clever software.

Photoshop photomerge worked well with these registered files to build the mosaic.

I've used a different technique here to overlay RGB stars over the NB ones. Basically removing the colour from them & shrinking them a bit, then overlaying the RGB.

There are way too many (did I mention Registar counted over 188,000?) to use star removal technique on this image.

I made a lot of mistakes along the way, and kept going back and re-doing elements and processes, learned a great deal about what to do and not to do for next time, but if you don't pixel peep too closely - it seems to have turned out ok overall. Time to move on at last!

For what it's worth, I'd like to thank the following IIS'ers, Bert for inspiration, Marc for his forum tips on mosaics, and Mike, M&T & Fred for constructive criticism along the way.

C&C always welcome

Cheers

Andy