Corona Australis - now with MORE DATA

[rmuhlack (Richard)]

A good run of clear weather has meant that I've really been able to crank out the images over the last few weeks. Leaving the scope set up in the backyard (protected during the day by ye olde camp shower tent) as well the extra features of my new rig have really helped reduce the wasted time seting everything up before an imaging run. This must be what it's like to have a permanent obs

Anyway, this is my first attempt at this target. Lots of faint dust is pushing the uncooled DSLR to the noise limit. Perhaps I've pushed it too far (??) and so an additional night of imaging it may required to bring the noise under control whilst still retaining extended detail. Any advice here would be appreciated Have been trialling ISO400 for my last few image runs as well, and am finding a lot more star colour is being recorded, but maybe this has been at the expense of noise in the extended regions of the image?

Details: 43 x 5min dithered subs, collected over two nights. Processed in Pixinsight. Hi res version here: http://www.astrobin.com/full/39410/B/?

Comments welcome I am really feeling like the quality of my images has improved a lot recently, and a big part of that is having lots of quality images from the experts amongst us here on IIS to emulate and strive towards.

[rustigsmed (Russell)]

Hi Richard,

You've got some wonderful detail / colour in there.
Hopefully you can iron out the smokey sections.

Cheers

Rusty

[Larryp (Laurie)]

Looks like its coming up well, Richard.

[h0ughy (David)]

yeah you have pushed it but a repro on the data should produce the goods. drop it back a notch

[rmuhlack (Richard)]

Thanks guys - its good to get some feedback to know I'm heading in the right direction. If the weather is clear and still again tonight I think i'll collect some more data. That, plus a repro, should hopefully do the trick.

Originally Posted by h0ughy

yeah you have pushed it but a repro on the data should produce the goods. drop it back a notch

its that preview window in pixinsight when Im using curves As soon as I apply the process, it shows me what i would look like if I applied the same again. I see the preview and go "wow - look at all those features and colours that are starting to come through" - so I apply again, and again etc. I need to learn to balance the "wow - that looks cool" with the "ouch noise". LOL - too trigger happy

To compare my progress I now have Marco's APOD rendition of this object up in PI now too. Nothing like setting myself a challenging goal

[Ross G]

Great looking capture Richard.


Ross.

[rmuhlack (Richard)]

Well I've been working on this one for the last few night. I now have this up to 125 x 5min dithered subs.

I have been able to reveal significantly more detail in the darker dust lanes. Still a little bit of noise visible in the darker areas, but at 125 subs i'm not sure if there is much more SNR that my camera (a modded but uncooled DSLR) will realistically record, and so any further improvements from here will most likely come from more skilled processing. I have used Pixinsight to process, but as I said before Im still learning so any advice on how to improve this image from a processing side is welcome Nowhere even remotely close to Marco's magnificent APOD image of course (which has been my processing reference), but I am still quite happy with what I have been able to produce, and it has definitely been fun to use Marco's image as the yardstick to aim for

Hi res image here: http://www.astrobin.com/full/39678/?mod=none

[multiweb (Marc)]

The latest version with added data is really very nice. Well done.

[strongmanmike (Michael)]

I agree with Marc ...keep going

Mike

[LewisM]

Beauty Richard - I tried this last year from my site with the EOS, and it was a failure. Will try it again sometime soon, maybe when I finish p-Ophiuchi

[tilbrook@rbe.ne (Justin Tilbrook)]

Wow Richard!

Looking great with more data, and like your processing.

Cheers,

Justin.

[IanP]

Richard, this is really nicely processed !!!


Btw, do you use (master)BIAS frame for callibration?

[rmuhlack (Richard)]

Thanks for the kind words everyone. The extra data and feedback on the first version certainly was helpful when processing this new version.

Ian - I used the Pixinsight batch preprocessing script to calibrate my lights. That script requires the use of darks, flats and bias frames/masters. I believe the bias frames are used to scale the darks to the exposure time for the flats and if necessary the light frames as well (although in my case the dark exposure time is the same as the light frames)

So yes, a bias master was used. Why do you ask?

[IanP]

I thought you did.
Just looked the other day at the stretched bias file of my 60Da and it’s incredible how much of “bad” stuff it adds to darker images, where the SNR is low …

Once again, congratulations, brilliant afford and brilliant result !!!