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View Full Version here: : M8, Me too, struggling with the colours


gbeal
04-06-2008, 03:15 PM
Didn't want to gate-crash Clive's post, but like him (and I suspect many others) I am trying to work the "correct" colour balance.
It IS a subjective thing and therein lies the problem.
Is there an easy way?
Taken a few nights ago, FS102 using an AP 67CCD telecompressor, QHY8 6x900 seconds. Acquired and processed with Maxim DL, and CS3. Guiding via maxim and QHY5.
Cold clear and breezy here as I type, so am looking to try again, wider this time.

bluescope
04-06-2008, 03:29 PM
Colours look pretty right to me Gary ! All any of us can do is look at other people's pics .... particularly of people like Messers Gendler, Croman, Pugh etc to name but a few.

:thumbsup:

Alchemy
04-06-2008, 05:19 PM
Crash away gary, if you read what jase posted on my thread RE the G2V color balance that seems the best way to officially determine..... now if someone will just circle the G2V star i will be away:lol: The Hipparcos catologue lists them so i will have to do some research.

I worked on the theory that there is some reflection nebulosity around the bright cluster and surrounds, and the Ha extensions should be a reddish color of some sort.

i have attached 3 different versions of the same image( all one of mine), one Blue, one middle and one Red, the Red is the one most put up but i think it should be more to the middle..... just my opinion. The only thing done is changing the Blue /Yellow slider its the same image with a huge difference. of course you can tinker with the green/ magenta too.

Heh, heh now ive crashed your post :whistle:

[1ponders]
04-06-2008, 05:54 PM
Nice pic Gary. Looks pretty damn fine to me. :thumbsup:

While I haven't tracked down a G2V star like Clive's planning, (maybe I should :lol: Go for it Clive, I'm looking forward to seeing how you go. You may just start the end of the eternal discussion ;) ) I do use the colour balance process described by R. Scott Ireland and it seems to do a pretty fine job. From the look of yours I'm guessing you used a similar process. Correct?

jase
04-06-2008, 07:08 PM
Geez guys. You need to get out more. ;) Attached is TheSky database listing all G2V stars and a flat file dump for those who love to manipulate data for their chosen telescope software.

Alchemy
05-06-2008, 01:35 AM
thanks jase that just saved a bunch of research,, organised by Ra too

Now i can have a go at it ...... just hope one of those stars is in my image.:prey:

Tamtarn
05-06-2008, 10:38 AM
Seems a long time since you posted an image Gary. Very nicely framed and not overdone.

Regarding colour balance. We agree what other have said it's up to you're personal preference. We always have a few images from some of the best imagers on line and compare them and decide which one is most pleasing to us. Then try and get as near to that as we can. Sometimes it's not that easy :lol:

Terry B
05-06-2008, 10:47 AM
The G2V stars give a good starting point. I have imaged some with both my little CCD and my 40D. It works well for the CCD but less so for the 40D bacause of the poor Ha sensitivity. Ha doesn't make up much of the spectrum of the G2V stars so the balance is still incorrect on images that contain lots of Ha.
I haven't tried it (I don't have a Ha filter) but probably if you took a normal colour image and balanced it via a G2V star and then took the same image through an Ha filter then added that data in as extra red you would get a more accurate rendition of the colour.
I reality, I don't think it matters. It's important for science images but unimportant for pretty pics.