Eta Carina 8 hours 25 minutes

[gregbradley]

I took this one in my recent trip to my dark site.

Quite windy during the LRGB component so I used 5 minute subexposures instead of 10 minutes ( I find them sharper and smaller star sizes as well on faster scopes due to the small wells on the 8300 chip).

I used a MMOAG with this one and it is the way to go for guiding. It did a good job despite the wind. I threw out the bad subexposures (about 1/3rd of the images).

AP140 with 155TCC (reducer/corrector) FLI ML8300, MMOAG, Lodestar guider, PMX mount.

8 hours and 25 minutes HaLRGB.

http://www.pbase.com/gregbradley/image/142203219/large regular size

http://www.pbase.com/gregbradley/image/142203219/original large size

Greg.

[Stevec35]

A nice image Greg although the stars seem to "get in the way" a bit. perhaps a faded minimum might be worth trying.

Cheers

Steve

[gregbradley]

Thanks Steve. I did some star reduction and you're right it improves the overall look of the image.

Greg.

[Octane]

Wow, that is one dramatic Eta Carinae!

I quite like your judicious use of tasteful contrast in this rendition.

Nice one, mate!

H

[gregbradley]

Thanks H. I thought it turned out better using the 8300 camera rather than the 16803 camera. I used both at first and didn't like the overall look of the 16803 chip.

I've been wanting to use the 8300 camera on the AP for a while now. On paper its a better match for the fast optics. Downside of course is the FOV is smaller. Hmmm perhaps a Microline 29050 is back on the wish list!

Cheers,

Greg.

[allan gould]

A really impressive image of my favourite nebula. Where in the world did you find over 8 hr + of imaging time? Even sacrificing virgins in Brisbane won't get you more than 40 minutes!

[gregbradley]

LOL:lol:

Yes in Sydney clear skies are rare as. Over the mountains though the skies are different and tend to be drier. I was away for 4 nights and 2 1/2 were clear. As long as the weather comes from the west it tends to clear up at night (I assume low humidity and being on a ridge).

Greg.

[midnight]

Hi Greg,

That is a very detailed image but may I ask what are those small roundish looking contrasts (darker centre) in that centre 10% of the image there? I can only really see it at the orginal size.

Please excuse my ignorance but I am very interested. I haven't quite seen this before and looks like a lot of very small roundish darker sections there that have a noticeable contrast between light and dark.

Cheers,
Darrin...

[gregbradley]

I think those are just dust areas. Others may know more.

Greg.

[Paul Haese]

Hmmm,

good contrast, loads of detail but I just don't like the colour. Not sure about the key hole area really. Loads of magneta and maybe that is what is putting me off.

Dealers choice though.

[avandonk]

Looks good to me Greg.

Have you tried adding up to 30% of the HA to the blue channel to make up for the 'lost' Hbeta? The amount of course depends on the local extinction. This will make the reds more 'normal'.

The dust is showing up very nicely. You only need to see a Spitzer image to see how much is really there.

Bert

[gregbradley]

Thanks Paul. I'll have another look at this one from a colour balance perspective.



Thanks Bert. I do add some Ha in the blue channel. In this case probably more like 12%. The amount I add varies image to image but usually 12-20%.

Greg.

[alpal]

It's a truly magnificent image but I feel it needs to be reprocessed
to make it even better.
Greg - I think you'll have another go at it some time when
there are cloudy nights as the data is just so good.

[gregbradley]

Thanks for the encouragement.

I will do another repro shortly. After seeing Marcus's image I think my colour is a bit too brown.

Greg.

[alpal]

Greg,
I think you'll surprise yourself at what you can achieve.

Imagine what a guy like Ken Crawford could do with that data?

[strongmanmike]

Good, I've looked at this a few times but wasn't sure what to say :question:... so I'll reserve my comments till after the repro :thumbsup:

You need to make it individual, especially the colour, it's in the eye of the beholder, like M42, Eta it is like a chamelon :)

Mike

[wysiwyg]

Greg,

Its a pleasing image although I have to agree with the crowd above.
Its has that bombers logo look to it, far too constrasty IMO. Eta has many faint and fuzzy attributes, and those really need a softer touch.

Chers
Mark

[Peter Ward]

The stars look a little ablated, did you apply a minimum filter? I suspect (if so) it wasn't required

Otherwise the high-key processing is an interesting twist. :thumbsup:

[marco]

Quote Peter, I also see some kind of artifacts on the tiny details.. It may be the microlens affects of the 8300 though, not sure, heard a lot of things about this ccd..

Overall a pretty dramatic image Greg, surely the impact is there, but I would go for a less contrasted version (and I am one who usually like strong contrasts, in particular on colors ;))

Marco

[prokyon]

Details and colors are great!

[gregbradley]

Yes it needs a rework. When I grow up I want to be just like Ken! Sorry only kidding. Thanks for your input.



Its due for a repro. I actually liked the LRGB only version a lot. Perhaps I'll start there. Part of it is the data wasn't that great (I mean it still has a lot of detail but the wind pushed the autoguider around a bit).

Colours aren't quite right, contrast too harsh.



Yes its a bit too hard. A repro is in order.



The stars are originally too large. Even though the autoguider did a good job the averaging of the buffeting over 10 minutes left enlarged round stars. So decon is there and I did after Steve's post run some min filter which is in a plugin. Your take on the star rework not being required is probably spot on. Cheers.

It needs a rework. The image isn't there yet. Thanks for your input.



Interesting. Which artifacts do you see? The only issue with this chip has been small wells and overblowing bright stars occassionally otherwise its a near perfect chip. I haven't seen microlense artifacts. What are you seeing there?

I agree too contrasty.

Thanks for your input Marco, much appreciated.




Thanks for that. I hope you like the repro when done too.

Greg.

[Ross G]

A great photo Greg.

The colours are great

I love the dramaric effect of the higher contrast.

Ross.