Nik's Tricks Of The Week: Perfect LAB Curves Each Time
Nikolai
Registered Users Posts: 19,035 Major grins
Nik's Trick Of The Week #1.
LAB curves is a very powerful tool, but it's also dangerous: slight mistake, and the whole image gets a nasty cast. How to make sure the AB adjustment curves are perfectly symmetric? Here's the tip:
To ensure the line goes through exact center, adjust your bottom anchor point and the click on the toggle bar, which is conveniently located just a few pixels south.
If the curve line does not move - you're dead on:-).:clap
Otherwise use your Left and Right arrow keys for precise adjustment, using your mouse to toggle the bar and verify the symmetry.
That was easy, huh?:wink
Nik's Trick Of The Week #2.
Tired of adjusting those darn curves each time? Here's another big time saver.
Once you got a pair of perfectly aligned AB curves (c.f. the Trick #1) at, say, 1st grid line, just click "Save..." button, and name it AB1 (or LAB1).
Next, do the same for the 2d grid line, save it as AB2, etc. It will take you less than five minutes to create all four basic curve layouts. Once the work is done, they always will be there waiting for you: just hit the "Load..." button and choose the one you think is most appropriate, it's instantaneous!
Thanks for watching!:thumb
Stay tuned for the next episode of NTOTW:lust
LAB curves is a very powerful tool, but it's also dangerous: slight mistake, and the whole image gets a nasty cast. How to make sure the AB adjustment curves are perfectly symmetric? Here's the tip:
To ensure the line goes through exact center, adjust your bottom anchor point and the click on the toggle bar, which is conveniently located just a few pixels south.
If the curve line does not move - you're dead on:-).:clap
Otherwise use your Left and Right arrow keys for precise adjustment, using your mouse to toggle the bar and verify the symmetry.
That was easy, huh?:wink
Nik's Trick Of The Week #2.
Tired of adjusting those darn curves each time? Here's another big time saver.
Once you got a pair of perfectly aligned AB curves (c.f. the Trick #1) at, say, 1st grid line, just click "Save..." button, and name it AB1 (or LAB1).
Next, do the same for the 2d grid line, save it as AB2, etc. It will take you less than five minutes to create all four basic curve layouts. Once the work is done, they always will be there waiting for you: just hit the "Load..." button and choose the one you think is most appropriate, it's instantaneous!
Thanks for watching!:thumb
Stay tuned for the next episode of NTOTW:lust
"May the f/stop be with you!"
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Comments
Okay, I guess I could just look at the histogram palette. Still, it's pretty convenient to see the histogram in the curves dialog like ratcheer's gimp screen shot.
For me it's much easier to click on a bar and see if the curve moves
Besides, the AB curves are 127-based, not 100 based (like L), so they don't add up that easily..
I have them set up as 100-based curves. Don't ask me how I did that, though.:D
We're probably talking about different curves. It's L-channel that is 100-based. A and B are -127..+127
I should add that this obviously is just Photoshop changing the scale it uses; I prefer it, and obviously I have Photoshop set up that way.
Hi, this is my trick to avoid color casts. I don´t use the curve tool.
1- I select channel A in the channel palette
2- I then increase contrast (basicly a centered S curve) as desired
3- I repeat the process for channel B
Let me know what you think