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Hi all thoughtt i'd capture the OIII data for my Dumbell image tonight. I was very lucky towards the end of the run as cloud came flooding in but for some strange reason didn't invade my ounce of sky, despite most of the rest of the sky being covered.. Lucky me!! :)

So.. Taken through the 127mm Apo, guided by the 102ED and imaged on the Atik 428EX through an Astronomik 12nm OIII filter.

120min of data in 12 x 600s subs, binned 2x2.  


I shall be grabbing much more data in all channels, but i think this is a pretty good start for now, albeit slightly out of focus... Not doing too bad after having about 18 months out. :)



Edited by Dark Horizon
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Hi Rich.

Tons of signal, well done!

Just wanted to commend on the focus, but then saw you already mentioned it :)
I also saw some artefacts (white streaks & dots) i suspect you were already fighting to get rid of those (probably hot pixels?). Did you do full bias & dark subtraction?

Kind regards, Graem

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Hi Graem, thanks for the comments. To be fair this is a very rough image.

, totally uncalibrated; no bias, darks or flats. I'm just learning to crawl again after such a very long time away from imaging.

I intend adding much more data and process in a less haphazard way, but first I need to nail my polar alignment... :)

Edited by Dark Horizon
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9 minutes ago, Dark Horizon said:

Hi Graem, thanks for the comments. To be fair this is a very rough image.

, totally uncalibrated; no bias, darks or flats. I'm just learning to crawl again after such a very long time away from imaging.

I intend adding much more data and process in a less haphazard way, but first I need to nail my polar alignment... :)

Hi Rich

Ah ok, so that then clears it up :) for a preview its already stunning. The result will be magnificent! :)

Kind regards, Graem

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I like your positivity, Graem, I'll give the final piece my best shot. 

One question, would you recommend that I ditch the out of focus data in favour of new data? I'm pretty sure there were about 4 less than ideal frames, which I used because they were there.....

Cheers, Rich.

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Difficult to say.

I would advise you to first get the other channels that you need and then decide at the end if you want to re-do the OIII.

It does seem pretty out of focus to my eye, so it could cause you blue haloes around stars. But it depends what you're going to use from the data. But honestly i'd decide that later. First get the rest, play around with combining the masters and then decide...

Kind regards, Graem

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That sort of out of slight lack of focus responds really well to deconvolution, why not have a try - this is just on your posted image, the original data should respond even better:


Also it's highlighted lots of pairs of small dots, one above the other, that are in your original and look like a registration/stacking error?

Sorry to be the bearer of bad news.


Edited by Stub Mandrel
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