The Southern Cross, Coal Sack and Dark Doodad

nebulosity. (Jo) · #1 29-01-2014, 03:54 PM

G’day,

It was looking like it might clear last night so I thought I’d try out some wide fields with the 1100D, I had to quickly nock up a bracket to attach the camera to the iEQ45, and was able to set up the mount in the paddock before dark, and then with a quick polar alignment I was away imaging

I’ve got a Canon/Nikon adapter so I used my Nikon 85mm with an IR/UV cut filter and paper aperture mask to stop it down to around F4.

On fiddling around with different exposure times and ISO’s I found 3 minute exposures at ISO 1600 was pretty sweet so I went with that.

The first thing I imaged was the California Nebula as there seems to be some sort of big molecular cloud around that area, it came up pretty well, I’ll post a pic once I’ve finished processing it.
Next I thought I’d like to do a bit of a mosaic around the Southern Cross as my last attempt didn’t turn out very well, so yeah, here it is,

Four images, 3 minutes each, ISO 1600, Canon 1100D with Nikon 85mm lens at F4. Stitched in Hugin, with further processing done in Nebulosity and Aperture.

I’m pretty chuffed with how it turned out, hope you like it. As always, any tips or criticisms appreciated.

Check out a larger version Here.

Cheers
Jo

gregbradley · #2 29-01-2014, 03:59 PM

Beautiful fine resolution and round stars. Good choice for exposure.
Seeing as your tracking is good you could even go 15 minutes ISO400 and go even deeper. Its worth a try.

Was that auto white balance? It could be taste but white balance seems a tad warm. On a Nikon 4800 kelvin worked well. Canon's seem to be a bit browner in hue so perhaps some experimentation there in Lightroom?

The Nikon 85mm F1.8G is one of Nikon's sharpest lenses but can have some colour fringing wide open. I don't see any there so F4 is good. I noticed with my copy CA went around F2.8.

Greg.

cometcatcher (Kevin) · #3 29-01-2014, 04:42 PM

Blimey that's nice.

Is that 1100D a modified one?

Regulus (Trevor) · #4 29-01-2014, 05:25 PM

They're very nice pics.
Greg's probably right re Colour Temp and it would be interesting to see how it looks after a fiddle in your graphics program.
They are fine photo's as they are but if u do change it please re-post.
Anyone know off-hand what the ID of the small globular near the Doodad is?

Trevor

MrB (Simon) · #5 29-01-2014, 05:48 PM

Very nice Jo.
I think I prefer the warmer one, but that's personal taste.
I thought I could see some strange artefacts on the right side of the image which changed between the warmer/cooler images, but have just noticed it`s not there on the Astrobin version.

cometcatcher (Kevin) · #6 29-01-2014, 06:16 PM

Quote:

Originally Posted by Regulus

Anyone know off-hand what the ID of the small globular near the Doodad is?

Trevor

I believe that is NGC4372. There's another below it, NGC 4833.

tilbrook@rbe.ne (Justin Tilbrook) · #7 29-01-2014, 06:29 PM

Both Excellent Jo!

The 1100D is a good camera huh!!

Cheers,

Justin.

nebulosity. (Jo) · #8 29-01-2014, 06:29 PM

Quote:

Originally Posted by gregbradley

Beautiful fine resolution and round stars. Good choice for exposure.
Seeing as your tracking is good you could even go 15 minutes ISO400 and go even deeper. Its worth a try.

Was that auto white balance? It could be taste but white balance seems a tad warm. On a Nikon 4800 kelvin worked well. Canon's seem to be a bit browner in hue so perhaps some experimentation there in Lightroom?

The Nikon 85mm F1.8G is one of Nikon's sharpest lenses but can have some colour fringing wide open. I don't see any there so F4 is good. I noticed with my copy CA went around F2.8.

Greg.

Thanks Greg!

It probably is a bit warm, I had a bit more of a fiddle with the blues and cooled it down some, maybe a little to much?

Yes the 85mm is very sharp

there is still a slight amount of CA T F4 but quite manageable.

The white balance was on auto, but I had shifted it towards the reds a bit as my nebulae were coming out bright green and blue

if its clear tonight I'll have a go with your recommended colour temperature.

If long subs are an advantage well I will certainly give them a go, I did try a 5 min exposure last night and the stars were still perfect so I should easily be able to go longer.

Cheers
Jo

nebulosity. (Jo) · #9 29-01-2014, 06:32 PM

Quote:

Originally Posted by cometcatcher

Blimey that's nice.

Is that 1100D a modified one?

Thanks Kevin,

Nah, its a stock standard 1100d.

nebulosity. (Jo) · #10 29-01-2014, 06:37 PM

Quote:

Originally Posted by Regulus

They're very nice pics.
Greg's probably right re Colour Temp and it would be interesting to see how it looks after a fiddle in your graphics program.
They are fine photo's as they are but if u do change it please re-post.
Anyone know off-hand what the ID of the small globular near the Doodad is?

Trevor

Thanks Trevor

I'll certainly post the updated versions, I think Kevin's on a winner with the globs.

Cheers
Jo

nebulosity. (Jo) · #11 29-01-2014, 06:48 PM

Quote:

Originally Posted by MrB

Very nice Jo.
I think I prefer the warmer one, but that's personal taste.
I thought I could see some strange artefacts on the right side of the image which changed between the warmer/cooler images, but have just noticed it`s not there on the Astrobin version.

Cheers Simon, it's good to have your opinion, the small Jpegs do contain a lot of artefacts as they are massively compressed to to fit in the 200 kb limit, the astrobin one shouldn't have this problem.

Jo

nebulosity. (Jo) · #12 29-01-2014, 06:56 PM

Quote:

Originally Posted by tilbrook@rbe.ne

Both Excellent Jo!

The 1100D is a good camera huh!!

Cheers,

Justin.

Thanks Justin

The 1100d is an Awesome camera!!!

. Sure know what I'll be buying when I have the money

nebulosity. (Jo) · #13 29-01-2014, 08:18 PM

Here is an image of the Dark Doodad itself, same camera, lens and settings as the previous image but this one has 18 subs, also darks and flats applied.

Check out the larger version Here.

Cheers
Jo