Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Orion Nebula at SGL6

G2EWS

By G2EWS
in Imaging - Deep Sky

Recommended Posts

G2EWS

G2EWS

Posted
Posted

Hi All,

Be gentle with me, this is my first attempt. Well not quite true as I did one other and put it on facebook, but the camera was out of focus!

This was 19 x 30 second shots on the telescope using the Nikon D3X. I spent a lot of time trying to get the image in focus and without a shield that goes on the front of the telescope this was the best I could do.

The images are stacked using Deep Sky Stacker which was a complete minefield for a novice, but after about 20 attempts I got something remotely resembling the Orion Nebula!

I then worked in Photoshop with many sharpen, noise reduction, curves, levels, back ground copies and finally Nik Viveza to get the black correct. It was again an act of jumbling with the various settings to get the colour out, remove the horrendous marks on my D3X sensor - Thanks to my photography mate Peter for coming over yesterday and getting rid of them! - and making the blacks, black.

Nonetheless I am very pleased with it and look forward to getting the future ones in better focus to start with.

Best regards

Chris

post-23987-133877565617_thumb.jpg

Link to comment
Share on other sites
  • Replies 57
  • Created
  • Last Reply
NickK

NickK

Posted
Posted
sorry to rain on your parade but the bit you have as bright blue should be various shades of red. Also there is virtually never any black in an astro picture.

Artistic license! :)

Good amount of detail for 30 second subs (I had a look by playing with the curves).

Link to comment
Share on other sites
saturn5

saturn5

Posted
Posted
sorry to rain on your parade but the bit you have as bright blue should be various shades of red. Also there is virtually never any black in an astro picture.

Dennis

Yep,the sky aint black so your photography mate got that wrong for you.

Link to comment
Share on other sites
malc-c

malc-c

Posted
Posted

I guess that the argument over post processing will go on and on... what is normal anyway, we all see what's around us slightly different to the next person.... I bet if you looked at 100 images of M42 you would be hard pushed to find two identical... Having said that the majority of them would tend to be towards the red end of the spectrum rather than blue... but the image is very well focused and has a lot of detail.

Link to comment
Share on other sites
malc-c

malc-c

Posted
Posted
The one I posted from SGL6 was a very subtle salmon pinkish. I didn't muck about with the colours at all, it's just what my camera picked it up on the night.

And very nice it looks too... but who's to say that that colour is the true colour, and not just the way a particular CCD is sensitive or tuned to.. if you follow my drift. To me it is the most natural and given the human eye's ability to pick up colours, probably what it would look like if doing a fly pass in a space ship :)

Link to comment
Share on other sites
G2EWS

G2EWS

Posted
  • Author
Posted

Hi All,

Many thanks for the comments and encouragement.

Hi Dennis, interesting comment! Fortunately it did not rain on my parade just made me realise that not only do we see differently but as I found out DSS has many different ways of processing the same image. I came up with mono to red, purple, blue and all colours in between which included green!

As to there not being any black in an Astro Image that one does surprise me! I have in my newbieness seen many photographs of this type. My feeling is that those that appear to be very grey and noisy appear to be taken by those who have not used a good quality camera. Then there are those that appear very good but still appear grey. Then there are the images I see in quality books and magazines. Now they all appear to have a good dark sky, but not necessarily black.

So why is this I wonder? It is my opinion that the photographer processes their images in the way they feel suits them best. In my newbieness I really like black skies! Oh and it hides the horrendous marks that were on my sensor of course :)

Hi Stewart, fortunately my photography mate just cleaned the sensor on my camera as I had made a pigs ear of it. It was me who did the processing. As mentioned above I liked the black , but guess as I learn more I won't! So many things to learn in this new hobby of mine. I guess I will get there in the end. Problem is of course, when will the end be :(

Best regards

Chris

Link to comment
Share on other sites
roundycat

roundycat

Posted
Posted

Chris, as you said at the beginning 'be gentle with me' so I will.

In the first place you have a sharp result with some genuine depth to it. That alone puts you well up the pecking order. What I do have a problem with is that when beginners post something that is completely the wrong colour so many people come along and say it is brilliant when it is not.

If you image with a mono CCD camera the first thing you need to do is to characterise the spectral response of the camera and filters. With a DSLR you can still do that but you have much less control over the finished result. The DSLR should give you a reasonable colour result straight out of the box provided your white balance is somewhere near white.

What is not really acceptable is to present an emission nebula as bright blue. You may as well photograph a traditional London bus and make it green! It doesn't help for people to say that your picture is good when it is totally the wrong colour. All that does is to confuse the true beginner who then doesn't really know what colour things should be.

M42 is mainly an emission nebula, that is to say, it is made up of ionised hydrogen and the emission line is at 656.3nm or deep red. You have also recorded the Running Man nebula (to the top left in my re-work); not only is that a real success but the running man is a reflection nebula and should be blue! Judge the colour by looking at the work of renowned experts, the variations there are minimal.

Correct colour is not a question of how we, as individuals, see it. What I suggest we should be doing in our astro pictures is to show the objects as close to natural as possible. Most of this stuff is invisible to the naked eye but we know what colour it should be from the type of object.

I took the liberty of re-working your picture by selecting M42 and using colour balance in Photoshop, not a tool I normally ever use. That allowed me to put some red in M42 without affecting the Running Man which remained blue.

If you should decide to re-process try not to saturate the core, keep it a more natural colour and do not (ever) set the background to black. A neutral background should read about 25:30:35 in RGB in Photoshop, that is a dark blue. There is a lot of faint nebulosity around M42 which is reddish. Actually Ha emission seen through a lot of dust. So the figures above ought to be almost reversed for M42 background. If you set the Info Palette second readout to HSB you can use the B reading (Brightness) to give you numbers from 0-100%. Backgrounds should be somewhere around 10-15%.

Hope this helps.

Dennis

PS, I turned it around to show it the right way up!

post-15519-133877565813_thumb.jpg

Link to comment
Share on other sites
G2EWS

G2EWS

Posted
  • Author
Posted

Hi Dennis,

Many thanks for not only 'being gentle' with me, but for a superb explanation of what I should have done and will indeed go back to do.

Just love the work you have done on it, makes me realise that I may have had the right data there already.

Once again many thanks for your help.

Best regards

Chris

Link to comment
Share on other sites
S.A.M

S.A.M

Posted
Posted

Nice effort for your first go at pubishing a picture. I have still to do that, so you are one up on me. I did manage to get a couple of pictures on Spaceweather.com so there is hope for me yet!

Peter

Link to comment
Share on other sites
Beyond_Vision

Beyond_Vision

Posted
Posted

Tracking and focus look good Chris so the data should be reasonable. Dennis is right about the colour balance and it's well worth going over the processing again. It might be worth hosting the files on a suitable site and letting others have a play with your data. This will then give you a good idea if the data set you have gathered is ok and it's potential.

Regards

Kevin

Link to comment
Share on other sites
G2EWS

G2EWS

Posted
  • Author
Posted

Hi Peter and Dave, many thanks for the comments.

Hi Dave, if I could get a web site going I would happily upload. Have been without a web site in my business for nearly two years because I am so rubbish at it! Grrr.

Best regards

Chris

Link to comment
Share on other sites
Psychobilly

Psychobilly

Posted
Posted

Hi Chris...

have a look at dropbox.. free file hosting

www.dropbox.com

Once you have it installed copy the files to the public folder... right click on it and copy the public link and post it on here...

I could invite you... that way we both get extra free space...

Always have your stuff when you need it with @Dropbox. 2GB account is free! http://db.tt/xKCGM61

Peter...

Link to comment
Share on other sites
G2EWS

G2EWS

Posted
  • Author
Posted

Hi Peter,

Many thanks for the info and link.

Set up an account, dropped the 19 RAW files into the public folder, but when I get a link there only appears to be one file in there! Any ideas?

Best regards

Chris

Link to comment
Share on other sites
G2EWS

G2EWS

Posted
  • Author
Posted

Hi Peter,

I think I get it! They are slowly uploading. I spot a second one is now green in my folder.

Will upload the link once they are all uploaded.

Best regards

Chris

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.