View Full Version here: : NGC4565 with QSI
allan gould
11-06-2010, 02:38 PM
From my location in BrisVegas, this galaxy was just skimming a large tree in my neighbours yard. But despite the low level I was pleased to get the final luminance image from the skyglow. It 14x5min with QSI583WSG thru a 10"SCT with f6.3 FR. Starwipe really helped me eliminate a gross gradient from the final shot. Levels and curves in PS then grad removal with Starwipe. A big thanks to Ivo at www.siliconfields.net.
Allan
h0ughy
11-06-2010, 05:46 PM
Al it looks a little too processed or clipped?
allan gould
11-06-2010, 05:55 PM
Agree Dave but had to do that to get any image at all from it being so low, swimming in the soup and flitting in and out of the tree leaves.
h0ughy
11-06-2010, 06:09 PM
do you have a soup shot to compare?
jjjnettie
11-06-2010, 06:28 PM
You've got some lovely detail in the galaxy itself Allan.
tonybarry
11-06-2010, 07:43 PM
Allan, that looks great. Good work with the QSI.
Regards,
Tony Barry
David Fitz-Henr
11-06-2010, 07:52 PM
That's a nice image Allan, especially considering the challenging conditions.
allan gould
12-06-2010, 10:57 AM
Just for you David
h0ughy
12-06-2010, 12:03 PM
Ahh i see you have pushed the red channel far too far.....:P
:lol: :rofl:
Seriously though - great shot Allan - have never imaged, but saw once at Cambroon through Ron's dob
Pretty low to N even for Bris, so heroic stuff shooting through all that sky glow :thumbsup:
h0ughy
12-06-2010, 01:37 PM
image processing commandment n0 1 thou shall not clip thy image
can i see some chicken and corn soup;)
peter_4059
12-06-2010, 02:28 PM
Nice shot Allan for something that is so low in the North.
Me senses a miraculous PixInsight Dynamic Background Extraction reprocess in the wind......;)
JD2439975
12-06-2010, 04:46 PM
Got an eye on this one myself, a classic "flying saucer" galaxy.
Actually several very nice galaxies in that little patch of sky.
Allan it's certainly a challenge to wipe the soup off low, faint objects & for an hours worth of data that's looking pretty good.
Keep at it.
irwjager
13-06-2010, 12:49 PM
I always love seeing people tackle the not-so-usual suspects, despite clearly sub-optimal conditions. Well done!
allan gould
13-06-2010, 05:15 PM
Thanks for all the kind comments. I may try to get some more data but I really think that data combined with better processing may be my real saviour.
But thanks for the input as its really appreciated.
Sometimes is just good enough to notch up your own photo of an object no matter if its not a masterpiece - at least its yours and you know what you had to go through to get it.
h0ughy
13-06-2010, 05:23 PM
Didnt mean to offend Allan - merely give some constructive help:innocent:
multiweb
13-06-2010, 05:51 PM
Very nice details in the dust lane. Impressive. :thumbsup:
allan gould
13-06-2010, 08:55 PM
David - none taken at all. Your observations were spot on and constructive.
Appreciate the fact that you took the time to comment.
irwjager
14-06-2010, 01:28 AM
Actually David, that's most likely StarWipe's doing.
Allan mentions there was a gradient present before he put it through StarWipe as a last step, so that means that the image can't have been clipped before it was put through StarWipe.
StarWipe maximizes contrast, removing any background light such as natural skyglow, Gegenschein etc. StarWipe does not clip however; it will never subtract a bigger value from a pixel than is the background light level (unless some extremely aggressive settings are used).
It will make images appear unnatural to some, but that is easily corrected by adding back a baseline level. The consensus for natural skyglow seems to be between 8-10 for red, green and blue. Personally, I think doing so is a waste of dynamic range as it defacto reduces contrast, making intricate detail harder to see. When it comes to aesthetics however, the debate's been going as long as there have been 'submit' buttons... :)
Looking at the final result (which is pretty damn detailed!), and taking into account the sub-optimal conditions, I can't really fault Allan's processing.
allan gould
14-06-2010, 04:03 PM
Had a go at reprocessing without clipping etc. I think its better, but there you go it just needs more data and less atmosphere. Thanks for all your comments as they are much appreciated.
h0ughy
14-06-2010, 04:44 PM
big difference Allan - well done
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