PixInsight - RGB Combine help

[AlistairW]

Hello,

I have RGB calibrated images, which I am trying to combine with the ChannelCombine tool. I have come up with the following though - eeek !! - What am I doing wrong ?

Thanks

Alistair

[Adreneline]

Hi.

After calibrating I register the r, g and b components with StarAlignment. I then crop off black edges with DynamicCrop. Next I apply DBE (or ABE maybe) before deciding if I need to use LinearFit before finally combining the registered inmages.

I basically follow this tutorial:

http://www.lightvortexastronomy.com/tutorial-preparing-monochrome-images-for-colour-combination-and-further-post-processing.html

HTH's

[Buzzard75]

I haven't used PixInsight yet, but it looks to me that your G frames may have just been inverted and mirrored. Not sure how that happened.

[Adreneline]

7 minutes ago, Buzzard75 said:

Not sure how that happened.

After a meridian flip maybe? - and no registration before combining? 

[ChrisEll]

Actually rather nice in its own right... the most psychedelic M81/82 I've ever seen!

[Buzzard75]

7 hours ago, ChrisEll said:

Actually rather nice in its own right... the most psychedelic M81/82 I've ever seen!

Makes you wonder what Bode was smoking in his cigar. *ba dum tss*

[ampleamp]

Another vote for the lightvortex tutorials, and if you havent already, take a look at Harry's Pixisight video tutorials. Using both will give you a solid grounding for some of the more fancy stuff PI is capable of. As has been said, registration with Star Alignment will align your channels - align all your channels to the same frame, i ususlly align on a good L or Ha frame as this is where the majority of the signal tends to be.

[wimvb]

A bit late, since you already got an lrgb image, but here's my recipe:

Calibrate r, g, b separately. In stead of the standard c_ prefix of calibrated subs, give r subs the r_ prefix, g subs g_, blue subs b_. Put them all in the same directory. Use the best sub as reference for star alignment. It's crucial to use only one sub as reference for ALL subs, irrespective of filter used. The reference sub doesn't need to be part of the stack. Align all subs at the same time. This will ensure best alignment. Integrate r, g, b subs to create 3 masters (or 4 with L)

Linear fit, use the master with best snr as reference.

Rgb combination then dynamic crop. Before you apply, save the instance to the workspace. Use this instance later on the L master if you have one (or on any other master, eg Ha). Apply dynamic crop.

Then DBE, colour calibration, etc.

Hope this helps.