advice with processing colours.....please :)

[Andywilliams]

Greetings to you all,

I am begging some expertise and assistance (again!!)

I managed to get 35 minutes on orion last night and have successfully stacked in DSS. My issues seem to start in processing.

I was hoping to see a 'flame' coloured flame nebula but it stubbornly stays red which may simply be down to not enough time at the camera....dew was the issue (late autumn here) and i haven't figured out how to process images from different nights imaging)

Anyhow, i have posted here my attempt at processing (gimp) and also the original DSS file in the hope that some of you may be able to apply your expertise and see if you can't make it look more pleasing......and also help me by explaining how you did it!

Also, I would really like to know where you think I've gone wrong on my processing.....have I over/under cooked it etc.

As ever I am most grateful for any assistance.......processing is a tough nut to crack!

Thanks in advance all of you and below are the technicals.

Seeing was a bit misty and orion was low to the western horizon.

yes, its upside down.....i'm down under!

canon 40D modified, 135mm, f5, ISO 1600

skywatcher star adventurer

18x120seconds lights

18x120seconds darks

20x8000/sec bias

stacked in DSS

Ok.....strike this one.....after spending an hour and a half uploading 61mb files.....it's somehow totally failed to post them   

permission to swear loudly !! 

 

[bobro]

Some things that might help (what I do with DSS & GIMP) :

As your camera is modified it will produce red biased images. If the RGB histogram peaks are aligned in DSS before saving the 16 bit TIF file the colour balance will be better. Saving the file with a saturation of around 20 also helps with correct colour balance.

Use a file sharing site such as dropbox to share large files.

If it takes too long to upload large files, convert them to jpeg. They can then be posted on this site. jpeg files are often all that is required in order to obtain useful comments.

HTH

[Andywilliams]

Many thanks Bobro for these suggestions. I am heartened to see that your tips for DSS are what I am doing !

Thanks for the top tip re dropbox.

I was thinking that I could convert these pics to jpeg but could someone process the DSS image as a jpeg? I would have thought a lot of the info would have been lost? but i'm a fair technophobe so its outside my knowledge.

 

[Andywilliams]

Here is my processed image that I refer to above.

As you can see.....a good collection of vignetting and gradient.

Any suggestions on how to improve it would be gratefully received.

Despite my whinging......this is my best image to date and gives me a little smile every time I open it

[Davey-T]

Nothing like your first recognisable astro image to inspire you, some of mine are really awful but I think they gave me more of a buzz than many later "better" ones.

Have a browse through some Y'Tube videos, there's lots of useful stuff on there much of it specific to M42 it being a popular target.

Dave

[bobro]

That's not bad at all. jpeg images can be processed to help show what is possible, but of course shouldn't be used in processing a final image. It looks like your image hasn't been processed with flats - these make a real difference - see below for roughly what flats could do by removing vignetting and gradients.

 

[ollypenrice]

Without doubt the programme to sort out colour is Pixinsight. It does many more things besides but I would buy it just for Dynamic Background Extraction, which can take out vignetting, colour gradients and colour imbalance with almost supernatural efficiency. I run it on absolutely every colour layer I produce, despite living at an extremely dark site.

Olly

 

[Andywilliams]

thanks Bobro.....I haven't quite made the leap to flats yet.....better get learning pronto !!......that's a massive improvement though.....thanks heaps

[Andywilliams]

Bobro....how did you manage to remove all the faults in my picture?....was that with pixinsight?

[bobro]

I used Gimp. Have a look at Doug German's YouTube videos - excellent ! There is one on gradient removal. Better to take flats though to start off with the best image.

 

[wimvb]

Nice widefield from limited time on target. Getting a good orion neb and a good flame/horsehead in the same pic is a remarkable feat, even for an experienced astrophotographer, simple because of the huge dynamic range. I think you've done well here.

To get the best out of a pic like this, I would probably create a copy. Process one for the orion neb, and the other for the flame/hh. Then blend as layers in gimp/photoshop. (Wow, can hardly believe I write this, as I use PixInsight exclusively. )

Imaging over several nights isn't dufficult. If you can, leave the rig untouched between night. If you can't/won't, try to leave the mount or tripod untouched. Align the imaging camera with RA and DEC. Expose a single frame for 30 seconds and slew the RA+ during exposure. This will create a straight star trail. Then loosen your camera and turn it. Repeat until the star trail lines up with either the long or short side of the sensor/image. Do this every imaging session.

The only thing left is to do an accurate star alignment each session. Use a high power (barlowed) eyepiece for this.

Take flat frames after each session. 15 or so is usually enough. It's not absolutely necessary to take flats at the same iso as light frames, as long as you calibrate them correctly.

Good luck