LAB colour mode.

I've just started experimenting with LAB colour mode in photoshop. It's amazing.
It opens up a whole new world of possibilities that I hadn't even considered before.
Anyone got any thoughts on LAB colour?

Yes, it is a powerful color space. Have a look at Dan Margulis' book, Photoshop Lab Color. After reading it for the third time, I now do most of my editing in Lab.

Herb

Fat Sam wrote:

I've just started experimenting with LAB colour mode in photoshop. It's amazing.
It opens up a whole new world of possibilities that I hadn't even considered before.
Anyone got any thoughts on LAB colour?

As you are doubtless aware there is a lot of information about using LAB for sharpening.
While there are theoretical benefits to performing some other operations in LAB or other color spaces remember that eventually you have to go back to an 8 bit (or less) RGB world for practical use of your images. What you think you are seeing on your monitor or on a histogram may not have practical utility back in the RGB world or could even lead to undesirable effects when you convert back to RGB. However you certainly can learn what works and what does not.

"Fat Sam" wrote in message

I've just started experimenting with LAB colour mode in photoshop. It's amazing.
It opens up a whole new world of possibilities that I hadn't even considered before.
Anyone got any thoughts on LAB colour?

Yes, Lab is great, and well worth exploring. In curves it allows you to alter contrast without trashing the colors, and vice-versa. In the curvemeister class I give people the choice of whether to use Lab or RGB (and a couple of other color spaces), and Lab is the clear favorite among people who are just starting out, who have no previous preference for RGB. --
Mike Russell - www.curvemeister.com

If you read the first Chapter in Margulis' book you will learn that editing in Lab can often produce results that are either too difficult or even impossible to attain in other color spaces. I would say that's quite a practical benefit. In addition to sharpening in the L channel, other practical applications of Lab mode are to remove noise by blurring the a and b channels, to use the Shadow/Highlight filter in the L channel for bringing out shadow detail and to separate colors and make them more vibrant that cannot be done in other modes.

Herb

nsag wrote:

As you are doubtless aware there is a lot of information about using LAB for sharpening.
While there are theoretical benefits to performing some other operations in LAB or other color spaces remember that eventually you have to go back to an 8 bit (or less) RGB world for practical use of your images. What you think you are seeing on your monitor or on a histogram may not have practical utility back in the RGB world or could even lead to undesirable effects when you convert back to RGB. However you certainly can learn what works and what does not.

Herb wrote:

Yes, it is a powerful color space. Have a look at Dan Margulis' book, Photoshop Lab Color. After reading it for the third time, I now do most of my editing in Lab.

Hahaha. Funny you should mention that book. It's exactly the reason I got interested in LAB colour.
A pro photogtrapher mate of mine bought me a copy of it in exchange for me doing his website for him. I didn't want paying, but he's the sort of person who won't accept a freebie, and always finds a way of paying you somehow. So a few days ago, the postman arrived with a package from Amazon containing that very book.
An incredible reference source. I've haven't been able to put it down.

Mike Russell wrote:

"Fat Sam" wrote in message

I've just started experimenting with LAB colour mode in photoshop. It's amazing.
It opens up a whole new world of possibilities that I hadn't even considered before.
Anyone got any thoughts on LAB colour?

Yes, Lab is great, and well worth exploring. In curves it allows you to alter contrast without trashing the colors, and vice-versa. In the curvemeister class I give people the choice of whether to use Lab or RGB (and a couple of other color spaces), and Lab is the clear favorite among people who are just starting out, who have no previous preference for RGB.

The thing that blew mind was how easy it becomes to substitute colours. That's something I often have a need to do, and LAB mode makes it so easy it's frightening.

On Wed, 13 Jun 2007 08:18:59 -0700, "nsag" wrote:

As you are doubtless aware there is a lot of information about using LAB for sharpening.
While there are theoretical benefits to performing some other operations in LAB or other color spaces remember that eventually you have to go back to an 8 bit (or less) RGB world for practical use of your images.

What you think you are seeing on your monitor

*think*?

Your monitor *always* works in RGB and so if, while using the LAB color space, you find an adjustment you like (visually) you are ALREADY seeing it after conversion back into RGB.

or on a histogram may not have practical
utility back in the RGB world or could even lead to undesirable effects when you convert back to RGB.

If you see the effects then they have already been converted.

Unless of course there are some new monitors out which work directly in LAB!

Easy to use graphics effects:
http://www.ransen.com/

On 2007-06-13 13:23:03 -0300, "Fat Sam" said:

Mike Russell wrote:

"Fat Sam" wrote in message

I've just started experimenting with LAB colour mode in photoshop. It's amazing.
It opens up a whole new world of possibilities that I hadn't even considered before.
Anyone got any thoughts on LAB colour?

Yes, Lab is great, and well worth exploring. In curves it allows you to alter contrast without trashing the colors, and vice-versa. In the curvemeister class I give people the choice of whether to use Lab or RGB (and a couple of other color spaces), and Lab is the clear favorite among people who are just starting out, who have no previous preference for RGB.

The thing that blew mind was how easy it becomes to substitute colours. That's something I often have a need to do, and LAB mode makes it so easy it's frightening.

Lab is powerful,
but I'd recommend learning to be fluent in RGB and also how to work with CMYK friendly at least.
Remember most of the stuff printed is CMYK.

LAB should be used in the upmost dire situations that RGB can't overcome properly.
I don't see many of those.

The last thing we need is everyone working in a another colour module when it will end up being converted to RGB ( ok it's on the fly) and possibily to CMYK down the line. Seesh! two modes are enough... let's leave it at that.
--
Welcome to Papa Joe's

"Papa Joe" <Sorry> wrote in message

On 2007-06-13 13:23:03 -0300, "Fat Sam" said:

[re Lab color space]

Lab is powerful,
but I'd recommend learning to be fluent in RGB and also how to work with CMYK friendly at least.
Remember most of the stuff printed is CMYK.

LAB should be used in the upmost dire situations that RGB can't overcome properly.
I don't see many of those.

It's true Lab can rescue some images that RGB can't. You are fortunate if you don't encounter images that need contrast changes without shifting the colors around, or an increase in color variation.

The last thing we need is everyone working in a another colour module when it will end up being converted to RGB ( ok it's on the fly) and possibily to CMYK down the line. Seesh! two modes are enough... let's leave it at that.

I hope you wouldn't go so far as to say that two different beers is enough. Would you? As with our beverages, so with color spaces. We can be more effective if there are more options.

Seriously, I agree that CMYK and RGB are important. Each color space has weaknesses and strengths, and I even advocate using CMYK for images that will go back to RGB. Most beginners find Lab much simpler to use than RGB - it's only the people with experience who are set in their ways and want to stick with only RGB and/or CMYK, and those who, like yourself, are comfortable with two color spaces have a leg up.

The best color correction techniques go back and forth between three, and even four, color modes.
http://curvemeister.com/support/curvemeister2/help/Articles/ PickADoor.htm --
Mike Russell - www.curvemeister.com

On 2007-06-17 16:04:50 -0300, "Mike Russell"
said:

"Papa Joe" <Sorry> wrote in message

On 2007-06-13 13:23:03 -0300, "Fat Sam" said:

[re Lab color space]

Lab is powerful,
but I'd recommend learning to be fluent in RGB and also how to work with CMYK friendly at least.
Remember most of the stuff printed is CMYK.

LAB should be used in the upmost dire situations that RGB can't overcome properly.
I don't see many of those.

It's true Lab can rescue some images that RGB can't. You are fortunate if you don't encounter images that need contrast changes without shifting the colors around, or an increase in color variation.

The last thing we need is everyone working in a another colour module when it will end up being converted to RGB ( ok it's on the fly) and possibily to CMYK down the line. Seesh! two modes are enough... let's leave it at that.

I hope you wouldn't go so far as to say that two different beers is enough. Would you? As with our beverages, so with color spaces. We can be more effective if there are more options.

Seriously, I agree that CMYK and RGB are important. Each color space has weaknesses and strengths, and I even advocate using CMYK for images that will go back to RGB. Most beginners find Lab much simpler to use than RGB - it's only the people with experience who are set in their ways and want to stick with only RGB and/or CMYK, and those who, like yourself, are comfortable with two color spaces have a leg up.

The best color correction techniques go back and forth between three, and even four, color modes.
http://curvemeister.com/support/curvemeister2/help/Articles/ PickADoor.htm

Agreed,
the more you know the better.
But it's been 10 years and I'm still learning tactics with RGB, CMYK and the inbetweens.
I'd rather have experience with GCR settings and proper dot gain than learn to color correct in a 3rd mode.

--
Welcome to Papa Joe's