Tarantula Widefield from dark Wee Jasper

[iceman (Mike)]

Hi all

My family and I went camping at Wee Jasper (west of canberra) for 3 nights, and met up with Rod and his kids, and John (xstream) and Anna. We had a fantastic time - great company, great camping site and great dark skies.

Cloud ruined any chance for all-night imaging, and on the first night, the longest length of clear dark skies was spent drift aligning. I finally got around to taking subs, but was cut short due to clouds.

So with this Tarantula widefield, I only managed 4 x 180s subs (ICNR used for dark subtraction) @ ISO1600 - therefore the image is much noisier than I would've liked.

- Scope + Camera: ED80 + WO 0.8x reducer + unmodded Canon 350D.
- Mount: EQ6
- Guiding: Guided through 400mm f/5 refractor, using DMK21AU04 + PHD software
- Lights: 4x 180s, flats calibrated.
- Darks: ICNR used
- Flats: 15x 1/3s median combined
- Processing: Images Plus for calibration and registration/stacking. Photoshop for everything else.

I tried to present the tarantula with less cyan, but increasing the red only served to redden the whole starfield as well. I would've had to do selective processing on the spider - maybe next time.

I'm happy with the image for the short amount of data I was able to capture - I love the knots of red nebulosity to the left. The dark skies really help to get a nice histogram right off the camera.

I'm not happy with the noise, due to the low number of exposures and high ISO.

I'm not happy with the composition. I had difficulty finding a guide star and the only one I could find resulted in this framing. I needed more time and more clear skies!

I'm not happy with the rotation in the corners. I didn't spend the time to drift align as accurately as I should have, and as a result ended up with some field rotation. I cropped the image slightly to reduce it, but it's still there.

I'm not happy with the overexposed core of the tarantula, but didn't get time to take any shorter exposures to mask it out.

Anyway, thanks for looking. Comments/criticism most welcome.

I've got some Eta Carinae and a bit of Omega Centauri from the next 2 nights that I still need to process.

[EzyStyles (Eric)]

nicee one iceman! alot of small nebs around the spider and good widefield view. how did u find ICNR compared to without?

[iceman (Mike)]

Thanks Eric.
I like the results ICNR gives me, but don't like that I lose half the night without capturing lights.

My results with darks weren't good, but was probably due to temperature differences.

I will go back to taking darks, just need to keep a closer eye on the temps, and scatter some darks in-between the run of lights - rather than wait until the end of the session.

[[1ponders] (Paul)]

Nice Mike. I like the way you have offset the image. How are you finding the 0.8 FR now?

[xstream (John)]

Mike, I reckon it's a pretty good effort considering the conditions on that night.

[Garyh]

Not bad at all Mike for the amount of exposure given! The main thing is you didn`t get totally clouded out and and a great camp out. I used to live down around this area years ago and brings back memories of my camping adventures..
cheers