Ngc1808

[Ken]

Hi this was taken a few days ago, NGC1808 is a spiral Galaxy in Columba the dove. My flat frames from a previous image did not work to well causing a uneven background. I also used a synthetic green from a red blue mix as there was no green filter in the filter wheel.
Taken with QHY9 and 18" f4.5 Newt.
Lum.= 4 hrs. red=1hr blue=2hrs all 5 min. subs 2x2
Clear skies Ken.

[alpal]

That's a hard target & a nice photo.
I like rare galaxies.

The best other photo I could find was here:
http://www.flickr.com/photos/36587062@N04/3631659111/

[TrevorW]

Ken you are doing yourself a bit of a disservice with the processing remove the green tinge to the background do a gradient removal and selective colour adjustment on the background a few little touch ups in PS on a small jpg example attached, hope you don't mind, tell me if it's crap if you think I don't know what I'm talking about but definite potential here with that data IMO

Cheers

[strongmanmike]

Trevor...noooo, Kens version is much better, that faint halo around the Galaxy, those little background galaxies and tiny stars, ya trashed'em all man :scared:

Yeh it's got a bit of a green cast and some unevenness due to your flats issue but this is still a great and deep looking galaxy field shot :thumbsup:

Mike

[Ross G]

Great galaxy photo Ken.

I love all the detail.

Ross.

[Ken]

Thanks alpal for comment and link to nice image.
Sorry Trevor I realize you only had a small file to play with but I cant see any improvement , I was lazy not taking the filter wheel apart again to remove the extra narrowband filters and replace the green, oh for a 7 pos wheel.
Thanks Mike glad you like it, this was the first time I tried using flat darks which proved almost impossible doing sky flats in the time available at one set exposure length. Making a light box big enough is also a challenge, not sure if they make a 20" lum. panel?
I might be able to reprocess the colour layers with no stretching or digital development hiding the uneven background, as you are the king of repo's what do you think.:lol.
Thanks Ross glad you liked it.
Clear skies Ken

[Peter.M]

To get a 20 inch scope flat illuminated I would look into light emmiting capacitors. They are basically large sheets of evenly illuminated light. I have no idea what they are worth but they are pretty much the only large even illuminated surface I have come across.

[TrevorW]

Sometimes you have to sacrifice detail to improve the whole image, I would say that I've succcessfully removed the green tinge and improved the background evenness

My point was, I spent about 2 minutes on a 188k JPEG file not the original data, aesthetically with a little more work the final image could be improved. Attached is the same image with only the green tinge removed and some work on the background

A lot of people post with a green tinge overly prominent in their images and little work done on the background, these detract from the quality of the final image IMO.

Others may disagree

Cheers :thumbsup:

[Ken]

Thanks Peter I need to get this flat fielding issue sorted as it is limiting the performance of this setup. Dome flats look like the best value if I can illuminate evenly?
Clear skies Ken.

[multiweb]

Top shot Ken. :thumbsup: Trev I found that getting rid of the green almost always kill some of the details. Best of both worlds is to blend the layer without the green as 'color' on top of the original one. This way you colorise the original layer without affecting the small details.

[Ken]

Trevor the background does look better in your last post. From my personal taste I prefer a dark grey background rather than black and this is what I am aiming for in my future images, easier said than done I know.
Clear skies Ken

[Ken]

Thanks Marc for the processing tip I will remember that.
Clear skies Ken.

[strongmanmike]

They sure do...

The 11th commandment of imaging "Thou shalt never, ever, sacrifice detail" Detail is the light and the way, all hail the detail :bowdown:

Psalm 2:12 Sidonio's: "Without detail the Aesthetics lie"

:P

[TrevorW]

Amen

[allan gould]

I hear you, Brother :innocent:

[midnight]

Lovelly detail Ken. And good to see quite a few other "guests" in that image albeit much further away. I quite enjoy these galaxy images which also show many more in the distant as it also gives the subject a really good size/distance (and time I suppose) perspective.

Darrin...

[Ken]

Thanks for the post Darrin, I agree those faint fuzzies in the background can be interesting and give a sense of how deep we are imaging these days.
Clear skies Ken.