NGC3718

[alan4908]

My first attempt at NGC3718 which lies at a distance of about 49 million light years from Earth. 

It's a very unusually looking galaxy, featuring a twisted dust lane in the central region.  To the right you can also see the companion galaxy NGC3729 which, occurring to radio measurements, appears to be interacting with its larger partner.  At the top of the image, Hickson 56 can be seen, a grouping of five small galaxies that are estimated to be about 390 million light years away. 

The LRGB image represents just under 16 hours and was taken with my Esprit 150.

LIGHTS: L: 35, R:23, G:20, B:16 x 600s, DARKS:30, BIAS:100, FLATS:40 all at -20C.   

[Spitfire]

Nice Image.

I enjoy looking at these unusual galaxies.

Geoff

[MarkAR]

That's a cracker of a galaxy. Superb image.

It looks like that at sometime during formation it was knocked off its initial axis giving a twist to the dark band.

[Knight of Clear Skies]

Superb image of a candy-wrapper of a galaxy. Personally, I'd consider cropping off the left hand side of the image as there is not a lot going on over there.

[Brian28]

that very nice Alan 👍 

[Erling G-P]

Wish my image of it looked like this!

 

[alan4908]

21 hours ago, Spitfire said:

Nice Image.

I enjoy looking at these unusual galaxies.

Geoff

Thanks for the comment Geoff. 

21 hours ago, MarkAR said:

That's a cracker of a galaxy. Superb image.

It looks like that at sometime during formation it was knocked off its initial axis giving a twist to the dark band.

Thanks - yes, it looks like it has gone through a lot - also the interaction with its companion galaxy is interesting. 

21 hours ago, Knight of Clear Skies said:

Superb image of a candy-wrapper of a galaxy. Personally, I'd consider cropping off the left hand side of the image as there is not a lot going on over there.

Thanks - on the cropping front, I did consider a much tighter crop  but this time I opted for the interesting object suspended in space look.  

17 hours ago, Brian28 said:

that very nice Alan 👍 

Thanks Brian

Alan

[Jkulin]

That's Lovely Alan, I have been doing the same image and have about 20 hours on it so far, there is so much going on in the image, I have processed it about 5 times so and I'm still not happy with the outcome.

How did you find it to process?

[alan4908]

8 hours ago, Jkulin said:

That's Lovely Alan, I have been doing the same image and have about 20 hours on it so far, there is so much going on in the image, I have processed it about 5 times so and I'm still not happy with the outcome.

How did you find it to process?

Thanks for the comment John 

I found it quite difficult. The main problem for me was the background and the starfield, rather than the galaxy.  Specifically:

1.  There are some quite bright stars around the galaxy which if you stretch them at the same level as the galaxy,  become too bloated.  I resolved this by stretching some of these separately and then blending them into the image.

2.  Since I image in non-ideal conditions (eg the UK), I often obtain red halos around blue stars, this arises from the FHWM of the red stack being slightly larger than the blue stack. I resolved this problem by creating a halo mask around the stars in the red channel and then applying an erosion filter to only that channel.  I did this in Pixsinight but you can perform the equivalent task in Photoshop. 

In general, I'd suggest you examine your five results and decide which parts of the image you like and which you don't for each of your five attempts.  I sometimes find that processing the main object and the background separately  and then blending the results can give a better overall result.

Alan

 

 

 

 

[Jkulin]

Thanks Alan, Yep you hit that on the head, have you ever wished you could apply 3 or 4 masks at the same time so that you can work on a specific area?

I have got the galaxy virtually as I want, but need to then concentrate on the other areas, I will get there but doubt that it will look as good as yours.

[alan4908]

11 hours ago, Jkulin said:

Thanks Alan, Yep you hit that on the head, have you ever wished you could apply 3 or 4 masks at the same time so that you can work on a specific area?

I have got the galaxy virtually as I want, but need to then concentrate on the other areas, I will get there but doubt that it will look as good as yours.

Good luck with your processing, I'm sure you will get there  !

By the way, I didn't understand your comment on applying multiple masks simultaneously, could you elaborate ?

Alan

  

[carastro]

Excellent result and processing.

Carole 

[Jkulin]

12 hours ago, alan4908 said:

Good luck with your processing, I'm sure you will get there  !

By the way, I didn't understand your comment on applying multiple masks simultaneously, could you elaborate ?

Alan

  

Hi Alan,

Of course, sometimes you want to use a different mask for one area and then another masks to work on another are etc. The work around for me is to create a black mask and then apply that to a range mask to block out specific areas by cloning from the black mask, but rather than make a mask up like that it would be nice if you could make a specific mask up for one area, then apply an exisitng different mask to a different area and so on and then apply the changes.

Hope that explains things a little better.

[alan4908]

On 30/04/2020 at 08:28, carastro said:

Excellent result and processing.

Carole 

Thanks Carole 

12 hours ago, Jkulin said:

Hi Alan,

Of course, sometimes you want to use a different mask for one area and then another masks to work on another are etc. The work around for me is to create a black mask and then apply that to a range mask to block out specific areas by cloning from the black mask, but rather than make a mask up like that it would be nice if you could make a specific mask up for one area, then apply an exisitng different mask to a different area and so on and then apply the changes.

Hope that explains things a little better.

Hi John

Yes - masks are interesting objects to experiment with..

In Pixinsight, I found that the free GAME script (http://www.skypixels.at/pixinsight_scripts.html) is very flexible, allowing you to create "elliptically holes" of specific sizes in your black mask at specific locations. 

Alan

[Jkulin]

2 hours ago, alan4908 said:

Thanks Carole 

Hi John

Yes - masks are interesting objects to experiment with..

In Pixinsight, I found that the free GAME script (http://www.skypixels.at/pixinsight_scripts.html) is very flexible, allowing you to create "elliptically holes" of specific sizes in your black mask at specific locations. 

Alan

Hi Alan,

Great minds think alike 🤪😁, I came across that last night and just downloaded it before seeing your post, it really looks very good.

Thanks for your comments.

[Davey-T]

Nicely captured and processed Alan, another of my perennial unfinished projects 😂

Dave

[alan4908]

8 hours ago, Davey-T said:

Nicely captured and processed Alan, another of my perennial unfinished projects 😂

Dave

Thanks Dave !

Alan