NGC 6960 - From New Mexico to Newcastle

[Paxo]

A while back, I, and a few others, decided to have a bit of a dabble with the GRAS remote telescope system, and those with a good memory will remember the post I made of the Veil nebula taken with GRAS in New Mexico:

(click to enlarge)

The purpose of using the GRAS system for me was to get more experience of data processing (as well as the chance to image objects unavailable from my Northern reaches). Well a month later and a lot of water under the bridge and a lot of processing, new camera, upgraded set-ups etc, I decided to go back and revisit NGC 6960 from my own garden just outside Newcastle to see how I am doing. Now, please bear in mind the difference between the image above taken from dark skies and the image below taken from heavily polluted skies I am really happy with the result.

Now the usual details. To take some of the light pollution issues away, I decided to image in narrowband (the way to go I think for deep sky from my home location), so imaged in Ha, OIII and then added a standard green channel. Limited opportunity limited me to 5x5 minutes for Ha and OIII and 5 x 3 mins for the green channel. Equipment: Imaging scope WO FLT110 camera Atik 314L, Guidescope WO Megrez 72 guide camera Meade DSI III Pro, guided with PhD, processed in Maxim DL and Photoshop.

(click to enlarge)

I was surprised how much detail came through in the green channel given the LP here. Hopefully as the nights get darker I will concentrate on building up the number of subs for a given image, I think this is the way forward (but I am prepared to be contradicted).

As a side issue, I think I prefer the image from my back garden over the GRAS one, not even taking the immotive issue of the rights and wrongs of remote imaging, there is still that deep down satisfaction of it being all down to you, which (eating humble pie :oops: ) I have not really felt before. Will I keep the GRAS subscription; probably for the reasons given above.

Please enjoy and all comments welcome

Steve..

[steppenwolf]

Steve, this is a fascinating comparison and I prefer your 'own' image to the GRAS one especially after a little bit of a stretch - you have collected a remarkable amount of data from your location - well done! Hope you don't mind but this is my stretched version of your image.

[SteveL]

That stretched version looks much better, I believe there is a lot of data in there that can be pulled out. The fact that you took it from a light polluted sky that isnt really dark at the moment says alot about the system and determination.

I agree wholeheartedly with your thoughts about "doing it yourself" versus "doing it remotely". I have just had to let my GRAS subscription slide for a month or two due to a couple of tight monetary months (a huge vets bill hasnt helped!). will I continue with GRAS (and lightbuckets.com)... unsure right now.

[Paxo]

Thanks Steve and SteveL. I din't want to stretch the data too far in a fear of the green gradient appearing, but looking at it some more work can be done. Thanks for the comments and encouragement, it is much appreciated.

Steve..

[Cloudwatcher]

Thanks Steve and SteveL. I din't want to stretch the data too far in a fear of the green gradient appearing, but looking at it some more work can be done................

Steve..

Oh go on! Stretch it......... you know you want to!

Perhaps not quite as far as this though............

Cheers

CW

Click as usual.

[Paxo]

While you were on I had a stretch, a tweak, a pull, a cup of tea (decaffeinated) and came out with this:

(click to enlarge)

Getting better, I need to get more supple so I can stretch more!

Steve..

[algol]

all amazing given what was there to begin with just seems to magically improve each time.

[Starflyer]

Well done Steve you must be very satisfied to have captured so much detail at this time of year, lovely image.

Ian

[RobH]

Great job Steve, especially with so little imaging time available.

I too prefer your home image :hello1:

Cheers

Rob

[Cloudwatcher]

While you were on I had a stretch, a tweak, a pull, a cup of tea (decaffeinated) and came out with this:

Getting better, I need to get more supple so I can stretch more!

Steve..

Hehe! Great stuff............. He who dares,wins!

I agree with Rob and others........... three cheers for the home side!

Cheers

CW

[LostNSpace]

Great job Steve on the Veil.......Lots of detail there on your image......

Well done

Mark

[Kaptain Klevtsov]

Going great guns Steve, its a great image.

Couple of things for you to try:-

If you have Noel's tools, you can synthesise a green channel from the two narrow band channels.

If you don't, layer the OIII on top of the Ha at 50% opacity, flatten and call that your green channel.

Either method should get rid of the LP problem altogether.

Kaptain Klevtsov

[Paxo]

Thanks KK, I do have Noel's tools, and may give it a go. I actually used a standard 'broadband' green filter to get the green channel so there is one there. I have since got an SII filter (thanks to Anthony) so I can do the three narrow band subs in the future, but I can see how synthesising the green from the two narrowband images may help, thanks for the advice.

Done a quick synthesis of the green channel from the Ha and OIII data and got:

(click to enlarge)

Certainly brings out more detail, and looks very interesting and more vibrant, thanks for the tip KK.

Steve..

[RobH]

Hello Steve,

A thing I always do is get my red and blue subs first (or whatever narrowband filter I'm going to use for these). This way, you can always synthesise the green if the clouds roll in and cut your session short.

Unheard of for the weather to do that over here I know

Here's the technique I use...

http://www.starrywonders.com/bicolortechniquenew.html

Cheers

Rob

[Paxo]

Hello Steve,

A thing I always do is get my red and blue subs first (or whatever narrowband filter I'm going to use for these). This way, you can always synthesise the green if the clouds roll in and cut your session short.

Unheard of for the weather to do that over here I know

Here's the technique I use...

http://www.starrywonders.com/bicolortechniquenew.html

Cheers

Rob

Thanks Rob that looks very interesting and when I get a free moment I'll have a bit of a play around with this technique.

Steve..

[MartinB]

Lovely image Steve. I like your first edit much more than any of the others. When you have short overall exposure time you can't get away with stretching much without the image looking forced. Your first image looks so natural, the others have pulled out detail but they look like they've been dragged through a mangle. With poor S/N less is definitely more when it comes to processing. You do need a good monitor to see it though, I could make out very little on my work monitor.

[Paxo]

Thanks for those comments Martin. My suspicions have been that you are right for a while now and I need to get SN ratio up by taking considerably more subs, unfortunately the light pollution limits to relatively short sub 120- 180 seconds, but that's the prevailing conditions and half the fun is learning to overcome these. A lot of my images post a little 'dim'. I have a beautiful 22@ monitor specificcaly made for graphic design which is calibrated both in colour and in Gamma, and gives a very bright vivid image. Processing on this monitor gives a good image to me but often causes problems with the likes of CW (no criticism meant and please keep up the good work) who always pstretch the image more. I guess it's what please the author the most that matters, and I tend to agree, I prefer the first edit the most, its most natural looking.

Steve..

[MartinB]

The difference in monitors is a nuisance. Yfronto did a nice investigation into this and his signature is very interesting, I'm guessing you can read number 1.

The postings being a bit dim is also a pest. I gather this can be sorted by altering the colour profile used so that it matches that used by web. Don't know anything about this and need to look into it some more.