M101 LRGB

[cfpendock]

This target is a bit small for my set-up - Tak and Atik as in signature.  16 x 5 minutes each for RGB, and 30 x 5 minutes Lum, all un-binned, giving a total of 6.5 hours, taken at various times during the past month.

I noticed when stretching the Luminance channel that there are two very faint arms extending downwards from the right side of the image.  But these don't show in the final colour version, and I think would need VERY dark skies to pull out enough to show.

Comments and criticisms welcome.

Chris

 

[wimvb]

Lovely image.

You seem to have a colour gradient across the galaxy, though.

[cfpendock]

17 minutes ago, wimvb said:

You seem to have a colour gradient across the galaxy, though.

Thanks very much, Wim.  This sort of comment is precisely why I find this forum so useful.  I didn't take any flats for the image and I think this may have caused it.  I think this has resolved the problem:

Chris

 

[wimvb]

Much better. Do you use pixinsight? The reason I ask is that besides the colour gradient, you also seem to have a dark area around and in the galaxy. At least it looks this way on my mobile screen. In pixinsight this is a common outcome if samples in the background extraction process (dbe) are positioned over the galaxy.

If this is not the case, please disregard my comment.

[cfpendock]

5 minutes ago, wimvb said:

Do you use pixinsight?

No, I use an old version of photoshop.  I too noticed the dark area around the galaxy when I was processing, but I couldn't get rid of it.  I think it is possibly an optical illusion caused by the cloudiness of the galaxy arms?  I say this because sampling the tone in these "darker" areas shows very little difference to the general background.  

But thanks very much for your comment.

Chris

[Graham Darke]

I can make out those faint arms on the right now that you've mentioned them. Very nice image. 

[RichLD]

Really nice image, it's scale puts the galaxy nicely in context 

[RayD]

Very nice, great detail and lovely colours.  Well done.

[DaveS]

Yes, I can see those arms too. Very faint, but they're there. As you say, longer exposure with a dark sky would pull them out.

[Adam J]

On a huge stretch I can see those in my image too, I decided it was not going to happen though as I am guessing  I would need 20min exposures as a minimum and my sky is too blight for that. 

[cfpendock]

20 hours ago, Graham Darke said:

I can make out those faint arms on the right now that you've mentioned them. Very nice image.

Thank you very much, Graham.  Maybe with your TEC140 you could pull them out?

Chris

[cfpendock]

20 hours ago, RichLD said:

Really nice image, it's scale puts the galaxy nicely in context

Thanks, Rich.  Glad you like the scale - I didn't have much choice with the camera and Tak.  It would have fitted on the C1100, but the stars on that thing are not good!

Chris

[cfpendock]

9 hours ago, RayD said:

Very nice, great detail and lovely colours.  Well done.

Thank you very much, Ray.  The colours were actually pretty difficult to pull out - especially without flats.  I never seem ti find the time.....

Chris

[cfpendock]

9 hours ago, DaveS said:

As you say, longer exposure with a dark sky would pull them out.

Thanks Dave.  I think the key word are dark sky and longer exposure.  Particularly the former, and preferably without clouds which seems pretty difficult this year,

Chris

[cfpendock]

2 hours ago, Adam J said:

my sky is too blight for that

Not to say bright... But full of blighted clouds as well!  But it was interesting to see the arms - I had no idea they existed - most published images don't seem to show them.

Thanks for the comment, Adam.

Chris