I wanted to keep this years Astrofest to the lowest imaging/frustration level so I took the QHY8 OSC with my new 2nd hand VC200L and 6.4Flattener/reducer on the EQ6 mount.
The first image with this setup was Corona Australia Nebula with the globular NGC6723. The combination of the dust, reflection nebula and the globular are a favourite of mine.
This was a stack of 48x5min exposures at f6.4.
Comments welcomed
Last edited by allan gould; 03-08-2011 at 03:05 PM.
A very nice image. I like it. Lots of detail in the blue areas and sharp.
The only thing that takes my attention is the glob seems a little dull.
Perhaps a lasso, feather and a bit of curves to boost it in Photoshop?
A bit hard to tell with the image but are the stars on the left on average larger in the image than
the ones on the right? Perhaps some tilt in your camera/focuser.
Excellent work Allan. Has a crisp feel to it as though it snap focus sharp. My only negative critque is on the processing and probably what Greg picked up on. The glob looks flat as I think the data could be stretched more, in addition you've slightly black clipped the red and green channels. While this has boosted the blue reflection nebulosity, it hasn't done much to aid in balancing other aspects of the image. Would be worth seeing what more information you could extract from this data set. It should deliver a fantastic result.
A very nice image. I like it. Lots of detail in the blue areas and sharp.
The only thing that takes my attention is the glob seems a little dull.
Perhaps a lasso, feather and a bit of curves to boost it in Photoshop?
A bit hard to tell with the image but are the stars on the left on average larger in the image than
the ones on the right? Perhaps some tilt in your camera/focuser.
Greg.
Quote:
Originally Posted by jase
Excellent work Allan. Has a crisp feel to it as though it snap focus sharp. My only negative critque is on the processing and probably what Greg picked up on. The glob looks flat as I think the data could be stretched more, in addition you've slightly black clipped the red and green channels. While this has boosted the blue reflection nebulosity, it hasn't done much to aid in balancing other aspects of the image. Would be worth seeing what more information you could extract from this data set. It should deliver a fantastic result.
Greg and Jase
Thanks for the kind comments and in relation to the Red and Green clipping and the globular, I did a re-process on the image and I feel that it is now better. Id originally toned down the globular as I felt it was distracting but then realised, Why photograph it in frame if I didnt really want it there?
Greg, in relation to the stars being tighter on the right of the frame I really feel that its due to the dust extinction on the stars making them appear smaller on the right of the frame.
Thans for the comments as its really appreciated and Ive included a reprocessed image.
I hope you don't mind Allan but I did a bit of work to the image. I don't normally repro other peoples work, but thought this would be instructive for you (not that I am any expert). I think this version looks a little better and less flat. I will explain and just show you what I did.
First I did a shadows and highlights around 33%. Then I did a curves adjustment with the medium setting which I boosted on the right hand side. Small amounts are only needed here, large boosts tend to over burden the image.
Then I did a mask and a colour saturation to the stars but did not include the nabula. I used a gaussian blue of aroun 4 pixels on the boundary. The reason I did this is the stars are not fully saturated and I thought need a greater saturation.
After this I did a little smoothing via a double mask with only just a slight amount of guassian to each side of the mask.
It goes to show how much data you did get, but I still think longer subs would have helped.
Edit. it is still a little blue but some adjustment in the blue channel will make this look more natural.
