LDN 673 - more data!

[RickS]

We had a lovely clear night at Ten Chain Hill last Friday and I managed to collect another three hours of data before LDN 673 slipped below the roof of Peter's shed.

Scope: Tak FSQ-106ED
Mount: AP900
Camera: SX H-18, Astrodon E-series filters
LRGB: 240, 40, 40, 40 mins
Processed in PixInsight.

Larger version here: http://rickstevenson.smugmug.com/Astro-Photography/2011-09/19119853_LDGbrK#1515454494_WBv4DVZ-O-LB

Thanks for looking. Any useful processing hints for dark nebulae will be gratefully received ;)

Cheers,
Rick.

[ozstronomer]

Great shot Rick, The dark neb shows up nicely against that golden star field.

Well processed:thumbsup:

[gregbradley]

A good image Rick. But I feel in your effort to emphasise the dark dust areas you've overblown the main background washing it out a bit.

Greg.

[RickS]

Thanks, Geoff!



Thanks for the feedback, Greg. I should learn to sit on images for a day or two after I finish processing them. Sometimes they look different with a bit of distance and improvements are more obvious.

Cheers,
Rick.

[strongmanmike]

Hi Ricki

Have you updated it since Greg looked at it?

These dusty areas are tricky to process and as a result various final results come of that processing (is that stating the obvious :question:)...anyway, this looks pretty good to me :thumbsup:

Mike

[RickS]

G'day Mike,

No, that's still the original version. I haven't changed it.

I did concentrate more on the dark bits when I processed it and I will definitely have another go and see if I can do better.

Thanks for the comments...

Cheers,
Rick.

[jase]

A solid image Rick. I can see where Greg is coming from but the result does accentuate the main features. Its easy to fall into the trap of raising the blackpoint too high to increase contrast of the dark nebulae. A trick I sometimes use is to have two layers of the same image in photoshop. Stretch the data so they are similar in illumination. On the bottom layer (blend: normal mode), establish an S curve predominatly focused on constrast between the shadows and midtones. Keep the highlights flat or just give them a little bit of a push but not much. On the top layer (blend: lighten mode). This layer counteracts any clipping of the shadows assuming your bottom layer contrast is quite steep. I then adjust the opacity slider to taste. The muliply blend mode is also good for providing more contrast as is the shadow/highlights tool if not overly done. Of course, the above is all Photoshop related. I notice you are using PixInsight. In this case, I can't really help too much. I'm still learning many of its features myself. HDRWavelets are good and probably the only real function I know enough about to understand what it is doing to the data. Experimenting is the key. Keep at it. Looking forward to more in the future.

[RickS]

Thanks, Jase. I've been meaning to add some Photoshop to my workflow. I can do similar stuff in PI using PixelMath but it's not as easy to play around and tweak to taste. The PI authors are aware of this and apparently do intend to add layers one day. I'll give your suggestions a try!

Cheers,
Rick.

[Paul Haese]

Looks good to me Rick. I like the smokey feel to the image.

[TrevorW]

Seeing some real beauties on IIS of late and not the usual run of the mill targets either which is great to see

[RickS]

Thanks, Paul.



Thanks, Trevor. I'm new to astro imaging and this was my first attempt to get a better quality image after spending a couple of months taking the equivalent of quick holiday snaps. I thought I'd have a go at something a bit different and fortunately it didn't turn out too badly!

Cheers,
Rick.

[RickS]

Greg,

I went back to revisit this and noticed that the jpeg version of the image is a bit flatter and less saturated than the FITS version on the same (high quality, well calibrated) monitor. It is very noticeable when displaying them side by side. Interestingly, if I load the jpeg file into PI it looks the same as the FITS file. It's only when viewed in other applications that it looks different. Simple tinkering with colour settings in PI hasn't produced an instant fix so it looks like I have another opportunity to exercise my troubleshooting skills ;)

Cheers,
Rick.

[Stevec35]

Nice image Rick. It does look slightly washed out though.

Cheers

Steve

[Ross G]

Great photo Rick,

Very sharp and I like the contrast of the black against the background sky.

Thanks.

Ross.

[RickS]

Thanks, Steve. I have been playing with colour management in PixInsight and I think I have figured out why the jpeg file is less saturated than it should have been.



Thanks very much, Ross.