What do you use LAB for?

[skoobey]

I know what it does compared to RGB or CMYK, I just don't find it useful for much but masking?

[klev]

Re: What do you use LAB for?

I don't use it for anything. It's not that useful for most things with the possible exception of describing a specific color in an output referred manner. I found a good summary by someone else of why it isn't very useful for color correction. That hue shift isn't really atypical either. As mentioned it is a good way to describe something in a non-hardware dependent manner. I just don't know why you would want to use it for anything else.

[andrewrodney]

Re: What do you use LAB for?

I dont' use Lab in PS for anything other than viewing numbers.

http://www.ppmag.com/reviews/200509_rodneycm.pdf

http://www.ppmag.com/reviews/200510_rodneycm.pdf

[Shoku]

Re: What do you use LAB for?

1. Increasing color contrast - it does it more naturally than RGB or CMYK.
2. Removing color casts.
3. Masking
4. Removing Haze
5. Changing colors from one shade to another shade.

[Aladdin]

Re: What do you use LAB for?

1. Increasing color contrast - it does it more naturally than RGB or CMYK.
2. Removing color casts.
3. Masking
4. Removing Haze
5. Changing colors from one shade to another shade.

Finally, someone who happen to know what is he talking about, thank you Shoku.

6. Boost color (vibrant) without overlay saturating it!
Look here http://digital-photography-school.co...with-photoshop - Here is an actual video that showes it in action https://www.youtube.com/watch?v=YB2eib59nrI
7. Enhance contrast

LAB color mode is so powerful, it gives you the necessary tools to manipulate color at the "micro" level.

Its power come from the fact that it separates "Lightness" from color, unlike the RGB color mode, where if you change one, you change the other!

[skoobey]

Re: What do you use LAB for?

@Aladdin

um.. that's what "color" blending mode is for.

@Shoku and Aladin

Yes, I know those methods, but I don't find them to be essential, especially not on a daily basis.

[Shoku]

Re: What do you use LAB for?

@Shoku and Aladin

Yes, I know those methods, but I don't find them to be essential, especially not on a daily basis.

Like any tool, it's useless until you need it. Editing in LAB is far superior to RGB or CMYK under the right circumstances. Just as RGB is under the right circumstances, or CMYK is under most circumstances.

We use what works best - and LAB works great.

[skoobey]

Re: What do you use LAB for?

Strike me with another example, I'm curious!

[Aladdin]

Re: What do you use LAB for?

@skoobey

No one said that LAP, or any other tool for this matter, should be used on every job! the right tool for the right job!

LAB is not for every day work, but, as @shoku said, it is there when you need it.

The bottom line, ADOBE would not have included it in PS if it was not useful or useless!

Here is your strike, look at the attachment, I would not be able to do it in under 5 minutes if it wasn't for the LAB!!! (it is a quick and dirty job, no masks, no paying attention to shadows, ZERO D&B, did not protect the water or the concrete, just concentrated on the subject)

The usual disclaimer: IT IS NOT MY WORK AS YOU MIGHT KNOW BY NOW, IT IS OFF THE WEB THROUGH GOOGLE. I take no credit for the capture or the original edit, the before. However, I did the AFTER!

[insmac]

Re: What do you use LAB for?

For what is worth, LAB works for me mainly as a quick-n-dirty tool for major hue shifts across the image as well as increasing saturation in a certain direction.

As with everything photoshop, there are usually a few ways to do the same task but LAB is the fastest one to do the 'dramatic mood' kind of thing or just a final grading. I do like 75% of grading in LAB space.

You still need masking and varying opacity if you want to be precise with that but I find it the most convienient tool for color and that was just by trial and error, it just works for me but may not for someone else.

[mistermonday]

Re: What do you use LAB for?

I know what it does compared to RGB or CMYK, I just don't find it useful for much but masking?

In addition to the other uses referenced above:
- The adjustment of skin color using only two numbers (a channel & b channel) as opposed to 3 or 4 in RGB or CMYK. There is a distinct relationship between the a and b values and a specific range in which almost all skin falls. Adjustments are fast and efficient.
- Adjustment of Temperature and Tint with only two channels. BTW, those sliders you may use in Camera RAW or Lightroom shift the temperature between Yellow (warm) and Blue (cold) represent the b channel in LAB. Similarly Tint shifts between Green and Magenta (a channel).
- Precision color matching in LAB can be done by matching the Lightness and then applying any color. Yes this can be done in RGB but it can often be easier and faster in LAB.
- D&B can be done in LAB without the color shifts you experience in RGB using D&B Curve Adj Layers.
- Frequency Separation in which the HP layer is fully B&W, no color in it and all of the color is in the LF layer. You can not do this in RGB. There is a 3 layer technique in RGB that separates lightness and color but it is inaccurate and those inaccuracies are very visually noticeable.
- A smart object prepared in LAB Color can very comfortably be nested inside of an RGB file. No need to merge, flatten, or convert the object or layer.
LAB can be an extremely useful tool. It is a color space that forces yus to twist the way we think and work. Most people are not very comfortable with it. You can almost always find a way to work without it and reach your image editing destination without it.
Cheers, Murray

[Aladdin]

Re: What do you use LAB for?

In addition to the other uses referenced above:
- The adjustment of skin color using only two numbers (a channel & b channel) as opposed to 3 or 4 in RGB or CMYK. There is a distinct relationship between the a and b values and a specific range in which almost all skin falls. Adjustments are fast and efficient.
- Adjustment of Temperature and Tint with only two channels. BTW, those sliders you may use in Camera RAW or Lightroom shift the temperature between Yellow (warm) and Blue (cold) represent the b channel in LAB. Similarly Tint shifts between Green and Magenta (a channel).
- Precision color matching in LAB can be done by matching the Lightness and then applying any color. Yes this can be done in RGB but it can often be easier and faster in LAB.
- D&B can be done in LAB without the color shifts you experience in RGB using D&B Curve Adj Layers.
- Frequency Separation in which the HP layer is fully B&W, no color in it and all of the color is in the LF layer. You can not do this in RGB. There is a 3 layer technique in RGB that separates lightness and color but it is inaccurate and those inaccuracies are very visually noticeable.
- A smart object prepared in LAB Color can very comfortably be nested inside of an RGB file. No need to merge, flatten, or convert the object or layer.
LAB can be an extremely useful tool. It is a color space that forces yus to twist the way we think and work. Most people are not very comfortable with it. You can almost always find a way to work without it and reach your image editing destination without it.
Cheers, Murray

Thank you so much for your deep insight, I just learned few things I was not aware of, actually, I did not try before in LAP, I guess I had a "narrow" vision for it, Humm! sounds very interesting to do FS in LAP, Why the heck I did not think of it before on my own!

The only problem I have is how to insert it as smart object within the RGB space, logically, it would force converting the entire file to LAP (I am sure I am wrong)

@Murray: How to insert LAP into RGB as smart object without converting the entire file?

Thanks for your insight.

[mistermonday]

Re: What do you use LAB for?

Thank you so much for your deep insight, I just learned few things I was not aware of, actually, I did not try before in LAP, I guess I had a "narrow" vision for it, Humm! sounds very interesting to do FS in LAP, Why the heck I did not think of it before on my own!

The only problem I have is how to insert it as smart object within the RGB space, logically, it would force converting the entire file to LAP (I am sure I am wrong)

@Murray: How to insert LAP into RGB as smart object without converting the entire file?

Thanks for your insight.

No, there is no need to convert the entire file. Here is an example of the process.
- open a file and go to a layer that you wish to work on. In the example linked here, I just did Ctrl J to duplicate the background.
- Right click on the layer and from the context menu select "Convert to Smart Object".
https://www.mediafire.com/convkey/64...0doomlb46g.jpg

-You will see the following dialog box:
https://www.mediafire.com/convkey/b6...hw1wpamd6g.jpg
This is an important message. The layer is converted to a Smart Object. You can work on it and do anything you want with it in any color space or add layers, D&B, FS split or whatever you would normally do. When you are finished working on it, you click the close window X, you will be asked to save changes -MAKE SURE YOU CLICK THE SAVE BUTTON.

- In this simple example I performed 3 steps. I did Image > Mode LAB Color. The Ctrl % to select the b channel. Then Ctrl I to invert the channel and Ctrl2 to reactivate the composite view. It looked like this:
https://www.mediafire.com/convkey/b8...2rxytm7b6g.jpg

Next I clicked the close window box and when the dialog came up I hit the save button.
You are then returned to your original file. You have your background and then you will see your Smart Object layer. The SO is nested inside your main RGB image and it remains in LAB color.
https://www.mediafire.com/convkey/3e...5z72s9376g.jpg

BTW, you can have as many nested Smart Objects as you like within the layer stack and you can have nested Smart Objects inside of other Smart Objects. You can mix all the color spaces you like.

Cheers, Murray

[andrewrodney]

Re: What do you use LAB for?

Ouch, I prefer the before image, not that it can't use some work.

[mistermonday]

Re: What do you use LAB for?

Ouch, I prefer the before image, not that it can't use some work.

Ctrl +I