LRGB Combination

6 replies401 views
Patrick Graham avatar
Kinda baffled by this…..When using the LRGB Combination process,  I upload the individual light masters into their respective channels.  The resulting combination is a Monochromatic image.  No color whatsoever.   When I remove the L channel and just combine the RGB, I get the expected color image.  I'm doing something wrong but don't know what.  Should I add the L channel separately with pixel math?? Need a little help here.

Patrick
Engaging
Blaine Gibby avatar
Combine RGB and then apply a stretch. Then stretch your luminance and add it to the RGB image with the LRGB process, but only use the L option and drag the triangle into the RGB image. 

I ran into the same problem and this is what I found worked for me.
Patrick Graham avatar
Thanks for the tip….I'll give it a go

Patrick
Ian McIntyre avatar
I feel your pain. I seem to always end up with a cartoonish result on my initial blend.
Well Written
Jan Erik Vallestad avatar
Blaine is correct. Use channel combination to produce  your RGB master and after you've done all your processing in the linear stage sretch your RGB and L masters before applying L with the LRGB script with RGB unchecked. I usually make copies and apply L to see if I need to make any adjustments to saturation and/or lightness.

I've never seen cartoonish colors though, unless the channel combination result without any further processing counts. Then both SHO and HSO can yield some pretty intense colors. Once corrected they should be fine though.
Patrick Graham avatar
Thanks, Jan.   That makes a lot of sense, too about the copies and tweaking them as needed.  I appreciate the tips.

Patrick
Well Written Respectful
Brian Puhl avatar
Process RGB and Luminance seperately.  

RGB is where you will work on all your color balance, tweaks, etc.   You don't need to push for too much detail here.  RGB is simply that, your color.  

Process Luminance for the fine details, decon/blurX, the appropriate curves/levels,

Combine them in the non-linear stage at the end of your process.
Helpful Concise
Related discussions
PixInsight New Tool - Multiscale Gradient Correction Test
Yesterday a new version of PixInsight 1.9.0 was released. The release contains some nice features, but by far the most important one is the MultiscaleGradientCorrection tool (I): https://www.youtube.com/watch?v=BHE3J069NCo It is supposed to do backgr...
Discusses PixInsight features relevant to image processing workflows.
Dec 21, 2024
WBPP won't register frames from a specific filter for no apparent reason
Hello all. I'm facing a problem I don't understand why is happening. WBPP (v2.8.1) won't show in pipeline or diagnostics the registration of B frames but will register any other filters of the same target. It seems like it happens randoml...
WBPP registration issues may relate to channel combination problems.
May 31, 2025
Help needed with narrowband imaging processing in Photoshop
I am looking to produce Hubble pallet images from Ha, O3 and Sii filtered images in Photoshop CC. I have the filters but not used all 3 yet so I have been looking at Photoshop techniques on Utube and trying very hard to emulate a few and all I get is...
Relevant - explains uploading individual images into respective RGB channels, directly applicable.
Jan 6, 2022