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My 'Happy Christmas' dataset's here.


ollypenrice

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Hi All, once again it's been a great pleasure to share this passion with SGL friends so I'd like to say a small thanks to everyone by posting a link to some data we shot here this year. It's all yours to have a play with - just try not to show me up! :icon_mrgreen:

It's from the TEC140 Triplet Apo/Mesu 200/Atik 460 mono rig working at about 0.9 arcseconds per pixel, cropped to reduce file sizes and aligned to fit together in Registar. You'll find LRGB and Ha in the link, though the Ha is a bit of a token gesture at 2X40 minutes. However, I found I could use it to give a hint of the star forming regions.  There are no short subs for the central core but I found I could use the RGB layer as a substitute since the core was quite subdued in that set.

I hope this Dropbox link will work for you. 

https://www.dropbox.com/sh/pxrxxtkr6khwvsf/AADNDoXJZh4t7zjI3LdIirjea?dl=0

Have a great Christmas wherever you are and let's look forward to all those incoming photons in 2019...

Olly

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1 minute ago, FLO said:

That is a nice gesture ?

A Merry Christmas to you too, Olly. 

Steve 

Thanks Steve. Yours is the firm for nice gestures if ever there was one. Have a good break yourselves though I guess you must be just a bit busy at the moment!

Olly

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27 minutes ago, Davey-T said:

Thanks for the early Christmas present Olly, it will give a reason to use DropBox as they keep threatening to cut me off from lack of use.

Merry Christmas :icon_rendeer:

Dave :icon_santa:

Yer not supposed to open it till Christmas day!

Olly

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Well, by no means up there with the best, but here's one I've produced today.

I'm still on the learning curve, but I would be extremely happy with this if I had produced it from scratch.

Still have lots to learn.

LRGB_Combined_PS.thumb.png.fc6927b8a1cee191412ccc1215ecb88a.png

 

 

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3 minutes ago, newbie alert said:

Thanks Olly..very kind gesture of you...

Most of us are about to have cabin fever and the weather's not been helping much lately..

Merry Christmas to you too

Honesty compels me to admit that it isn't helping me either!!!

Olly

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That is lovely clean data, Olly.

 

I used CCDStack to make an L HaR G B, and did a bit of sharpening on the brighter areas in the Gimp with GMIC.

 

I'd be chuffed to bits if I could acquire such data myself.

 

 

OllysM51.jpg

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11 hours ago, Laurin Dave said:

Thanks Olly, very kind, it'll give us in the UK something to do until the cloud clears... (partly my fault I know) Is that the same data you used in your Astronomy Now article? 

Merry Christmas to you

Dave

Yes, exactly the same for the refractor part of the article.

Olly 

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11 hours ago, michael.h.f.wilkinson said:

Thanks Olly! Lovely data to work with.

Bit too noisy in the background, will handle that later

On this camera's data, Michael, I've evolved a technique for NR in the background. There seem to be a lot of dark background pixels for some reason so I find a brighter one and pin the curve at that point and above it, then lift the curve below it. This avoids pixel to pixel communication and so dodges the smoothed look of blurring alogorithms. This won't work on images containing darker-than-background dusty features, of course.

Olly

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1 hour ago, ollypenrice said:

On this camera's data, Michael, I've evolved a technique for NR in the background. There seem to be a lot of dark background pixels for some reason so I find a brighter one and pin the curve at that point and above it, then lift the curve below it. This avoids pixel to pixel communication and so dodges the smoothed look of blurring alogorithms. This won't work on images containing darker-than-background dusty features, of course.

Olly

I had been experimenting with curves a bit in a similar way, but wasn't that satisfied with the results. I think I will apply some filters we have developed at work for this. They can readily remove small speckle structures without affecting larger ones

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1 hour ago, ollypenrice said:

On this camera's data, Michael, I've evolved a technique for NR in the background. There seem to be a lot of dark background pixels for some reason so I find a brighter one and pin the curve at that point and above it, then lift the curve below it. This avoids pixel to pixel communication and so dodges the smoothed look of blurring alogorithms. This won't work on images containing darker-than-background dusty features, of course.

Olly

I've just tried that, and it works brilliantly!

Do you use this early in processing, or at the final stages?

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24 minutes ago, don4l said:

I've just tried that, and it works brilliantly!

Do you use this early in processing, or at the final stages?

Fairly early. I stretch luminance in a conventional way in Levels  until I've got the background up to about 19 or 20 as measured in Photoshop. (I would far rather stretch to a higher background like the 23 I can easily reach with my Atik 11000 data but this camera just won't get there without being blown out eleswhere.) At this point the fainter details and even middle range brightnesses will still have more to give but I stop and do the procedure I outlined above. Thereafter I continue to stretch but with the curve pinned at the 19 or 20 and below so that  the background never gets any more stretching. There is no point in lifting further up above the noise floor.

I'm glad the trick worked for you. I do a number of custom noise reduction procedures based on zooming in to pixel scale to see what's going on. The colour select tool is good for picking up similar rogue pixels which can then be fixed using other tools like saturation, colour balance or the Median filter. This can be less invasive then generic noise reduction but it assumes you can spot a noise pattern at pixel scale. Sometimes you can, sometimes not.

Olly

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Many thanks from me as well, ?lly.

I wish I could say that I've put your present with all other presents underneath the Christmas tree. But it's actually sitting on my harddrive, waiting for Christmas morning.

All the best wishes to you, and hopefully many clear nights in 2019.

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