Two Lab tutorials/articles

[Stroker]

Getting close to 24 hours. Normally wouldn't be so bad, but last night's physical activity was a bit extreme. Nothing like throwing your pH balance way out of whack. Something like that.

Anyways, I've been working on going on a rampage.Yeah, another rampage. Rawr.

Equating HSL and Lab

Lightness Limits Saturation

More to come.

[Stroker]

I adore being able to shift, offset, or translate ab in Lab. The commons tools for this seem to be Levels and Curves. Same thing possible with other tools, but I have yet to hear anybody talk about them.

But the thing that sucks about Levels/Curves is the drop-down. I know it's a minor thing, but it really gets on my nerves. I would much rather have the controls right there in one shot. Believe it or not, but Hue/Sat can be hacked to adjust ab colour balance with a bit of savy, and you will have the controls right there instead of having to switch channel controls.

- photograph that needs some general balancing
- Image > Mode > Lab
- New Layer and fill with L=50%, a=30, and b=30 (your colour palette is in Lab mode, right?)
- set Blending mode to Linear Light
- Advanced Blending
-- turn off L channel

Right about now you should be looking at a mess. Now for the fun part.

- Adjustment Layer > Hue/Sat and clip it to the Linear Light layer
- Open up the Hue/Sat dialog and get crazy with the Cheez Whiz

What you are basically doing is offsetting a and b in a particular direction. You use the Hue slider to set the direction, and use the Sat slider to set the amount. Seems to do decent enough with a little practice.

Should get you thinking about different ways of manipulating ab. Again, not without irony of some sort. Using a polar system to offset a Cartesian system. Man, that cracks me up.

[Stroker]

Offsetting ab

[Welles]

Oh my God! I'm actually starting to comprehend some of this. 3[

'Resistance is futile.' Enter at your own risk... 8))

[Stroker]

Oh my goodness. I lost a post. I'm talking about this on 3 different forums and I swore I was talking about a little something, but apparently not. I guess my head is working to fast to keep track of the little things. Or maybe I'm just going crazy.

Alright, Welles, time to use your noodle.

Read Steve's excellant work:
http://www.thegoldenmean.com/technique/curves3.html

And come up with a Lab variation.

Tip to Consider: You don't have to use a neutral. That is, you can translate a=60 b=10 to new values other than 0.

Now, where did I put that post...?

[p?tr?]

[confused]

[Stroker]

Patrick, I don't understand what you are trying to say. Care to clarify?

Took a slight detour to do some junk.

Major ab Balance

Basic Lab Curves
Scaling ab