• Welcome to Orpington Astronomical Society.
 

News:

New version SMF 2.1.4 installed. You may need to clear cookies and login again...

Main Menu

Orion Nebula and lots of dust

Started by MarkS, Jan 17, 2016, 18:56:14

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

MarkS

Another from Friday night.

Modified Sony A7S on Tak Epsilon 180ED.
3 hours of data in 30 second subs at ISO 2000 plus 10 min at ISO 640 and 10 min at ISO 200.



Larger version here:
http://www.markshelley.co.uk/Astronomy/2016/orion20160115large.jpg

There's a lot more I could do to bring out more detail in the brighter areas.  This was created simply by stretching one single HDR image covering the whole (massive) dynamic range.

Mark


Fay

Mark, dont know what you are complaining about with that camera. that is great, you will have gone through the whole universe in 7 days!!!!!

I am wondering if I should get one now!!!!!!!!!
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Carole

Fantastic image Mark, amazing amount of dust.

Carole

MarkS

Oddly, this image didn't seem to have much of a problem with the coloured banding - I don't know why.  Maybe it's more disguised by the dust structures.

Mark

RobertM

Oh what it is to have dark skies ...

If that was mine then I'd be framing it and putting it on the wall !!!

Robert

JohnP

Very nice indeed Mark - super image - the whole nebula looks like it is veiled in dust - Never see this any images I take :-( John

Mac

QuoteOddly, this image didn't seem to have much of a problem with the coloured banding - I don't know why.  Maybe it's more disguised by the dust structures.
Or the dust is not actually dust and you have discovered another banding problem,  ;)

Nice image.

Mac.

MarkS

An adjustment in PixInsight using HDRMultiscaleTransform has improved this image making it more "punchy" and restoring contrast in the very bright areas.  I'm very pleased with the result now - it's a rare thing for me to say.



Larger version here:
http://www.markshelley.co.uk/Astronomy/2016/orion20160115v2.jpg

All it needs now is some noise reduction.

Mark

Carole

QuoteI'm very pleased with the result now
Much better detail in the nebulae.
and so you should be Mark, it's an excellent image.

Carole

RobertM

That's one of the best images I've ever seen of that area !  Yes it may need some NR but that'll be easy - you've already done all the hard work.

Have you used deconvolution on it yet (I'm thinking primarily about resolving the trapezium) ?

That is APOD material.

Robert

MarkS

Quote from: RobertM
That's one of the best images I've ever seen of that area !  Yes it may need some NR but that'll be easy - you've already done all the hard work.

Have you used deconvolution on it yet (I'm thinking primarily about resolving the trapezium) ?

That is APOD material.

Robert

Thanks Robert.   Much appreciated.

I haven't done any deconvolution or sharpening on it, nor any noise reduction.  I'll give both a go when I get the chance.

APOD has recently had an "Orion Nebula with Dust" so I think I'm out of luck on that score:
http://apod.nasa.gov/apod/ap151229.html

Mark

Fay

very nice Mark. have you changed your mind about the banding now? is it easier to sort out than you thought?

Fay
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

MarkS

Quote from: Fay
have you changed your mind about the banding now? is it easier to sort out than you thought?

I hope so.  It looks like I can get around it by exposing the sky fog much further to the right - looking at the back-of-camera histogram that would mean getting the peak 3/4 from the left instead of 1/4 or 1/3 which is the normal recommendation.
Here's the post where I explain it: http://www.cloudynights.com/topic/519941-sony-a7s-split-sensor-and-banding/?p=7015094

I just need to verify this on a real imaging night.

Unfortunately it's too late for the data I have already shot - I'll never be able to calibrate out the banding.  Possibly I can try some kind of manual correction.

Mark

Fay

You have worked very hard to get it right Mark, i bet you slept ok last night!
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

MarkS

I've gone over to the dark side - now that Photoshop is so cheap (£10/month) it seemed a good time to try it out.

So I now have Photoshop, Lightroom and Adobe Camera Raw.

ACR has some nice features e.g. noise reduction that works really well and moe intuitive than the PixInsight equivalent. Despite the name it doesn't only operate on raw files. So my 16bit TIFF could be opened in Photoshop and then Filter| CameraRawFilter takes it back into ACR to adjust exposure, perform noise reduction etc.

So here is the (newly tweaked) version 3 of the Orion Nebula:


Larger version here:
http://www.markshelley.co.uk/Astronomy/2016/orion20160115v3.jpg

Mark

Fay

Really lovely Mark, yes such a lot of dust!

what version of PS do you get for £10 a month?
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Carole

I had forgotten that you never had a full version of Photoshop Mark, I think you used to use Photoshop elements. 

What is ACR I haven't come across it, unless it is only in the more recent versions of Photoshop.
Also what did you do to retain the star colour, something I struggle with.

Fabulous image Mark.

Carole

JohnP

Adobe Camera Raw... Lets you edit Raw files directly before opening in PS...

quote.... Adobe Camera Raw, which lets you import and enhance raw images, has been a must-have tool for professional photographers right since it was first released in 2003. Applications that support Adobe Camera Raw include Photoshop, Photoshop Elements, After Effects, and Bridge. Additionally, Adobe Lightroom is built upon the same powerful raw image processing technology that powers Adobe Camera Raw.

RobertM

That's also a great image, the PS'd version seems to have more definition and show fainter stars; is that the processing in PS giving you extra control ?

Must admit looking at PS myself for NB combination only a couple of weeks ago as its a bit fiddly in PI.

Robert

MarkS

Quote from: Fay on Feb 15, 2016, 10:13:13
Really lovely Mark, yes such a lot of dust!

what version of PS do you get for £10 a month?

Photoshop Creative Cloud


Quote from: Carole
I had forgotten that you never had a full version of Photoshop Mark, I think you used to use Photoshop elements. 

What is ACR I haven't come across it, unless it is only in the more recent versions of Photoshop.
Also what did you do to retain the star colour, something I struggle with.

Fabulous image Mark.

Carole

With Photoshop CC (and some other versions), if you open a raw file e.g. a CR2 file from Photoshop then it takes you into ACR to perform the raw conversion first.  But with Photoshop CC you can then go back into ACR to use the various sliders e.g. noise control that it provides.

Star colour is all about how you perform the main initial stretch.  If you use Photoshop curves to stretch your linear data you'll end up washing the colours out of the stars.  It's worth learning enough of IRIS to perform an arcsinh stretch. You just need to open your 16bit TIFF, stretch it and save it back.  Then open in Photoshop for the rest of whatever you do.

Quote from: RobertM
That's also a great image, the PS'd version seems to have more definition and show fainter stars; is that the processing in PS giving you extra control ?

Must admit looking at PS myself for NB combination only a couple of weeks ago as its a bit fiddly in PI.

I performed some deconvolution (which increased noise) then loaded it in Photoshop for final tweaking of the stretch and for noise reduction.  The deconvolution brought out the fainter stars.

MarkS

#20
More on star colour (for Carole) ...

The main problem for astro-data is that it has a very high dynamic range - effectively it is HDR (high dynamic range) data rather than a photo of the children and the dog playing in the woods.  Photoshop is excellent for tweaking photos of the children and the dog playing in the woods.  But for astro data you really need Photoshop's HDR tool suite.  So try Image|Adjustments|HDRToning - this allows you to stretch the data without losing star colour.  Not many folk know this  ;)

Quick tip - make sure you've carefully subtracted the light pollution background level and white balanced before you do the HDR Toning.  The  HDR Toning will automatically flatten the image (i.e. it will apply the previous adjustment layers) before it can proceed.

Mark


Carole

QuoteImage|Adjustments|HDRToning
I don't have this in CS3.

Carole



MarkS

Quote from: Carole
QuoteImage|Adjustments|HDRToning
I don't have this in CS3.


IRIS it is then!

Carole

#23
QuoteIRIS it is then!
I have installed it again but don;t have a clue what to do.

Carole

MarkS

Quote from: Carole
QuoteIRIS it is then!
I have installed it again but don;t have a clue what to do.

Carole

Here's a quick tutorial:
http://forum.orpington-astronomy.org.uk/index.php?topic=10675

Fay

Do you get Lightroom and Camera raw as well for that price? i thought it looked more like £17
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

Fay

I wonder what CC has that CS5 does not.
It is healthier to be mutton dressed as lamb, than mutton dressed as mutton!

MarkS

#27
Quote from: Fay
Do you get Lightroom and Camera raw as well for that price? i thought it looked more like £17

I'm on the Photoshop/Camera Raw/Lightroom package for £8.57/month.
http://www.adobe.com/uk/products/photoshop-lightroom.html

I'm quite interested in trying out the techniques here:
http://www.clarkvision.com/articles/astrophotography.image.processing2/

It has raised lots of controversy on the DPReview forum but the more I look at the maths behind it, the more I'm convinced Roger Clark is actually correct.

Mark


RobertM

Thanks for pointing that out Mark, it was a useful read; I think Don Goldman (astrodon) uses similar techniques.  I also think Adobe lens correction would be of great benefit and likely more useable than PI DBE.

Robert

MarkS

Quote from: RobertM
Thanks for pointing that out Mark, it was a useful read; I think Don Goldman (astrodon) uses similar techniques.  I also think Adobe lens correction would be of great benefit and likely more useable than PI DBE.

Robert

The main problem is that you can't apply flat frames.  So although it might work quite well for cameras with lenses, I wouldn't be able to use it for images from my scope - the flat frame is too complex.

Mark

RobertM

Likewise with my RH200.  I'm going to give the trial of CC a go, I still think it's quite expensive for what it is but compared with the money that goes on kit and in the scheme of things...

I think I might stick to PI for deconvolution and NR as I'm getting very good results and no artifacts though I'll defer to PS if it works out better.

Robert

MarkS

This is an interesting article regarding the colour of the area around the Trapezium:
http://www.clarkvision.com/articles/astrophotography.m42-trapezium.true.color/

However, mine came out whitish because the H-alpha mod introduces a lot more red.

Mark