NGC6744 my longest image yet 38hours 50 minutes

[gregbradley]

This is one of the most beautiful southern galaxies and I have always had a fascination with it since Brad Moore posted a luminance image of this several years ago.

It is also quite faint. Very faint really.

This image is the longest image I have taken to date. It is a total of 38:50 hours. It is HaLRGB 40 1295 295 255 235. 10 minute subs each and 7 hours worth were at 15 minute subs.

This image was taken over 3 years. The first 7 hours of the image was taken at my dark site in Bigga NSW with an RCOS 12.5 inch telescope. The next several hours was a Takahashi BRC250 and a FLI Microline 8300 camera with Baader filters. The last section
of about 14 hours is Planewave CDK17 with reducer at F4.45 and a Proline 16803 and taken at my home observatory. There is also TEC180FL and Microline 8300 several hours as well also at my dark site.

The BRC data was quite good. The RCOS data was good. So was the TEC180FL. The Planewave data not bad. Dark skies count for a lot when imaging.

It quite clearly shows the distorted spiral arm that reaches up to the small satellite galaxy and there is another galaxy down low in the image as well. I am not sure if that one is close to the main galaxy. It appears as though it might be.

http://upload.pbase.com/gregbradley/image/137118175/large regular

http://upload.pbase.com/gregbradley/image/137118175/original large

Greg.

[DavidU]

Fabulous image Greg.Good to see the exposure measured an days:lol:

[Octane]

Wowowow!

Can I make a suggestion of upping the saturation a bit?

Outstanding, Greg!

H

[gregbradley]

That's funny, yes it is in days.

I have an even longer version I'll post a link to.

Greg.

[SkyViking]

Wow that's outstanding, what an effort.
Good to see such a massively long exposure. I wonder what is the magnitudes of the faintest stars in that image...?

[gregbradley]

Since the first post I found another 7 hours of 12.5 inch RCOS data I added.

I also upped the saturation. Thanks.

I probably have another 6 or 7 hours of CDK17 data at F6.8 if I look.
That would put it over 40 hours.

There's something to be said for keeping your data over the years secure.

Greg.

[gregbradley]

Good point. How do you check?

Greg.

[allan gould]

Greg
Fabulous photo but please stop doing this as I've just retired and I don't have the years left to do this sort of astrophotography.

[jjjnettie]

Stunning work. An inspiration!

[marco]

Very beautiful subject Greg! It is an amazing collage of exposures/scopes/cameras, it had to take lots of time to process :) Congratulation also for the dept you reach.

I would consider to reduce a bit the luminosity of the center, it makes the colors (saturation) suffer a bit there.

Clear Skies
Marco

[swannies1983]

Talk about dedication...well done :thumbsup:

[h0ughy]

^^^^^^ what they said but with cherry's on top. Awesome but there are some dark halos around some stars where they may have been processed?

[atalas]

Great work Greg! a marathon effort yielding spectacular results! personally I hope you continue on with this project over the next few years aiming for the big 100 hrs.....wouldn't that be something.

Anybody who's imaged this sucker knows how tough this cookie is to break.

Awesome job so far!

[gregbradley]

Haha Allan I intend to do worse!



Cheers JJ.



I adjusted that a tad in latest version. I found another few hours from CDK17 at F6.8 I have added making it now 38:50 hours.



Thanks for that.



Perhaps the latest posting is a bit better there. The last data I added had tighter stars.



Cheers Louie. It pays to keep all your data from previous years.

100 hours, now there is a target! I don't know if anyone has ever done a 100 hour image. Do you know of one?

Greg.

[atalas]

Hi Greg,maybe Gendler but not all his data....my memory ain't what It use to be mate,could be wrong.

[Paul Haese]

Lots of data Greg. Good colour.

[Leonardo70]

Greg ... very impressive ... nice work on, with all the different kind of data right merged.

All the best,
Leo

[strongmanmike]

New extreme sport - Astro Imaging with Greg Bradley! - great project :thumbsup:

Mike

[Tandum]

Huge effort Greg. Congrats ...

[gregbradley]

He did a 90 hour M31 I remember that one.



Thanks Paul.



Thanks Leo. Its good to have all the data together in one image.



Hehe thanks Mike.



Thanks Robin.

Greg.

[Ross G]

Hi Greg,

Wow..what an amazing photo and what a beautiful galaxy!

Your artistry and technical skills have again raised the bar.

Thanks.

Ross.

[jase]

A solid image Greg. Well done. As H said, a bit more saturation would help. Out of interest, how far back did you go in the processing of the existing data sets from the other instruments? Did you stack the subs for all instruments as one stack or simply add the finished 16bit TIFFs as an overlay per instrument?

[niko]

:eyepop:

[gregbradley]

Cheers Ross. I am glad you liked it.



Thanks Niko.



More saturation?? I'll never win a Malin award at that rate:rofl:

I already upped it and I am happy with where it is. More and it starts to look unnatural.

I did both. One image's masters are in a hard drive in a crashed laptop but I have the finished image. A lot of the luminance was stacked together. I kept finding earlier images of it. Registar helped with some registering. You'd think Photoshop would have a decent registering tool.
The Transform function is dinosaur but if the images are close you can use it. CCDstack does not handle colour images well. The other choice would be Images Plus which handles colour images really well.

Greg.

[atalas]

Try AA5 Greg!

[Lester]

Wonderful image Greg. The longer the exposure time the more beauty is revealed. Thanks for the view.

[jenchris]

Why not just up the ISO to 1,600,000?
I've never seen anything so utterly amazing in my life - simply because of the time spent collecting photons.
If you owned Hubble,it may have been a nice pic. This way it is an amazing effort - well done indeed.

[John Hothersall]

That galaxy is definitely on fire with all that time, great arms.

John.

[Stevec35]

Pretty impressive Greg. Some of the stars do look a little over processed though, perhaps as a result of combining data from several instruments. Some people have suggested more saturation. Personally I would suggest less as you seem to be flirting a bit with colour noise in the centre.

Cheers

Steve

[gregbradley]

Good tip I'll check it out. Thanks.



Long exposure is always the aim but not always practical for a million different reasons. So it worked out well that I have accumulated 14 hours lately and another 7 here and 8 there so it all added up nicely.



Wow, thanks for the nice compliment! I am glad you liked it so much.



Cheers John. I've always liked this target. Some targets are worth effort.



Yes I was also thinking of perhaps blending the stars of one of the better images into it rather than building them up like that. I agree it would polish the image further.

Perhaps a project later on. I still have several images still unprocessed. We've had a good run of clear weather in the last month.

With regards to the colour saturation yes I think I am right at the edge with it and a bit backed off wouldn't harm the image look.
A little bit left in reserve to tame unwanted effects isn't a bad idea.

Greg.