Questions about LAB Mode in LR5.2

[Carl in Louisiana]

Is this something useful to learn to use or should I just stay with RGB Mode. Where would I go to learn more of the LAB Mode and how to use it in LR5.2?

[wmoore]

What is LAB mode ? I only have LR 4

[JPS]

What is LAB mode ? I only have LR 4

Hi Warrick,
don't use it myself or confess to know anything about it but this site should help.

http://phlearn.com/get-amazing-color...-anything-else
John

[FootLoose]

Dan Margulis says it is "the most powerful colour space available" : http://kelbytraining.com/online/watch/cs3_lab

[wmoore]

So they have added LAB mode to LR5.2

[jcuknz]

I used it a few times in earlier versions of Photoshop to separate out the color ... the A and B ... from the luminence ... the L.
The theory was that sharpening had less bad effect on the luminence channel than the color channels.
I believe that you can also use CMYK in a similar manner where K is the luminence channel to be sharpened.
By having control of the constituent parts you can make adjustment to change the balance between them. I remember playing around that way to no great result
Originally my PSP editor didn't have LAB only CMYK but current version has both.
Not sure if there is any connection between RGB and LAB ...is there? What?

[Carl in Louisiana]

After much searching the net I found this little tid bit. Apparently it is just for viewing LAB color values and that's it. Don't know yet how useful this will be.

http://blogs.adobe.com/jkost/2013/05...r-readout.html

[Carl in Louisiana]

http://www.crawfordenterprise.com/Ph...olorSpace.html

http://photo.net/learn/digital-photo...r-adjustments/

[Kris V]

So they have added LAB mode to LR5.2

If they did, I haven't found it.
If I want to work in LAB or CMYK mode, I use to PhotoShop.

[Colin Southern]

I use LAB mode a lot when processing landscapes. It's incredibly powerful, but it does take some getting ones head around.

The rub of it is that it works more like how our brains see colour rather than how our eyes work - ie as two colour opponent pairs (blue/yellow, and magenta/green).

Dan Margulis is the absolute master of it.

[lenelg]

In Photoshop, I find it useful to go into LAB mode, and select the lightness channel, before adjusting the exposure of an image with the curves tool, shadows/highlights etc. I feel I can make stronger adjustments while preserving the feel I want for the image.
As an experiment, make the same overall curve adjustment to an image in RGB mode, and to the lightness channel in LAB mode, and compare the two side by side.

[davidedric]

FWIW from the Lightroom Queen:

There’s now a L*a*b* color readout. It’s primarily used by the repro/scientific communities, but can be
useful for checking skintones (for ‘average’ skintones, if there is any such thing, keep a* and b* values
really close, often with the b* slightly higher).
• Right-click on the Histogram in Develop and select Show Lab Color Values to show them. They’ll replace
the RGB values, unless you’re soft proofing

[Colin Southern]

FWIW from the Lightroom Queen:

There’s now a L*a*b* color readout. It’s primarily used by the repro/scientific communities, but can be
useful for checking skintones (for ‘average’ skintones, if there is any such thing, keep a* and b* values
really close, often with the b* slightly higher).
• Right-click on the Histogram in Develop and select Show Lab Color Values to show them. They’ll replace
the RGB values, unless you’re soft proofing

The difference between RGB and LAB in this context is that LAB is a reference standard; specific numbers always mean the same thing whereas with RGB the actual shades of red, green, and blue aren't defined.

Lee Varis uses it (in part) to nail skin tones in his excellent book Skin.

[Simon Garrett]

I'm pretty sure I read a post by one of the LR designers on http://forums.adobe.com/community/li...ew=discussions about the lack of LAB support. I thought it was by Eric Chan, but I can't find it now.

The point was that the LR Basic Panel can achieve the same largely-independent adjustment of lightness and colour that you would do in Photoshop by means of LAB curves adjustment. In LR, the recommendation (from Eric and others) is to do as much adjustment as possible in Basic Panel, and that it shouldn't be necessary in most images to adjust curves as well. Certainly that's my experience since Process Version 2012 was introduced with LR4. However, it would be nice to have the option to adjust curves in LAB as well...