Terrific Tutorial for Setting Black, White and Gray points.

wxwax

I struggle to make the white balance/color correct in my images.

Most especially, I really don't know how to find the all-important gray point. I simply cannot look at an image and tell you which part is middle gray.

And yet I know that if I set good white, black and gray points, the color in my image will be enormously improved.

Today I found a tutorial on YouTube that clearly, simply and precisely explains how to solve this mystery, using Photoshop.

Here's the link.

DavidTO

Cool! It's very much like the Pop tutorial, but adds the gray point. It's interesting, in that video (of course nothing is calibrated), but the after looks wrong to me, as the skin tone is much too magenta. BUT: looks like a great technique!

wxwax

DavidTO wrote:

Cool! It's very much like the Pop tutorial, but adds the gray point. It's interesting, in that video (of course nothing is calibrated), but the after looks wrong to me, as the skin tone is much too magenta. BUT: looks like a great technique!

I agree, skin tone's waaaay off. But if it's properly white balanced, then I assume you have a good starting point for making the rest of your corrections.

When I get home from work, I'm a gonna play with it on some images. It already makes more sense that what I've been doing, which is use levels and Alt-click on the black and white sliders and move them around to find the white and black points. This looks easier, plus it gives me a gray point.

I did find it interesting that when setting the base values for the eyedroppers, he raised the gray by ten. Why raise it? Why not lower it, or leave it alone?

DavidTO

wxwax wrote:

I agree, skin tone's waaaay off. But if it's properly white balanced, then I assume you have a good starting point for making the rest of your corrections.

Someday, when I have time, I'm gonna run his tutorial steps next to the steps in the Pop tutorial, and compare the results.

saurora

That's a great tute Sid! I agree it's difficult to find that gray area, and it can make such a huge difference in the color of the image. Thanks for sharing this. :saurora

wxwax

DavidTO wrote:

Someday, when I have time, I'm gonna run his tutorial steps next to the steps in the Pop tutorial, and compare the results.

That would be very cool.

wxwax

saurora wrote:

That's a great tute Sid! I agree it's difficult to find that gray area, and it can make such a huge difference in the color of the image. Thanks for sharing this. :saurora

Awww, a kiss, shucks...

Nikolai

Sid,
1) Re: B/W points.
With all due respect, changing tools and using threshold seems like an waste of time (to me, that is). Both Levels and Curves dialogs (plain or adjustment layers) support Alt/Option mode, that temporarily switches your image to the "clipping mode". In CS3 it even goes as far as providing an additional "Show clipping" check box on the Curves dialog itself, so you don't even have to depress the Alt/Option button. You never have to leave the dialog...

2) As you guys have already pointed out, the result of this technique is that cast has changed from a strong yellow into a strong magenta.
Why? Well, we pretty much let the PS decide what's what.
When Dan spent several chapters in his books discussing the problem of Black and White points and "betting the image" I think he was on to something

DavidTO

Nikolai wrote:

1) Re: B/W points.
With all due respect, changing tools and using threshold seems like an waste of time (to me, that is). Both Levels and Curves dialogs (plain or adjustment layers) support Alt/Option mode, that temporarily switches your image to the "clipping mode". In CS3 it even goes as far as providing an additional "Show clipping" check box on the Curves dialog itself, so you don't even have to depress the Alt/Option button. You never have to leave the dialog...

2) As you guys have already pointed out, the result of this technique is that cast has changed from a strong yellow into a strong magenta.
Why? Well, we pretty much let the PS decide what's what.
When Dan spent several chapters in his books discussing the problem of Black and White points and "betting the image" I think he was on to something

While the method you talk about is good, it does lose the added control of being able to set the black point to a specific value, and does not remove color casts, as the black and white point droppers do.

Nikolai

DavidTO wrote:

While the method you talk about is good, it does lose the added control of being able to set the black point to a specific value, and does not remove color casts, as the black and white point droppers do.

You can set the values for the Black, Gray and White points once per session/life and then forget about them. All the methods will use these values. Dan suggests different values for them, but it's a judgement call anyway.

My primary point was that you don't need a trip to the threshold layer to find the clipping zones...

Mike Lane

wxwax wrote:

I struggle to make the white balance/color correct in my images.

Most especially, I really don't know how to find the all-important gray point. I simply cannot look at an image and tell you which part is middle gray.

And yet I know that if I set good white, black and gray points, the color in my image will be enormously improved.

Today I found a tutorial on YouTube that clearly, simply and precisely explains how to solve this mystery, using Photoshop.

Here's the link.

I remember reading something about this technique somewhere on dgrin before. Where was it?

Oh yeah, here it is.

DavidTO

Nikolai wrote:

You can set the values for the Black, Gray and White points once per session/life and then forget about them. All the methods will use these values. Dan suggests different values for them, but it's a judgement call anyway.

My primary point was that you don't need a trip to the threshold layer to find the clipping zones...

True, you don't NEED Threshold. I prefer it, though. It's more clear, at least in CS2 (haven't tried in CS3 yet) what is what.

Dragging the end points in levels does not use the black/white point settings, AFAIK, it just moves the black point up or the white point down.

Nikolai

DavidTO wrote:

True, you don't NEED Threshold. I prefer it, though. It's more clear, at least in CS2 (haven't tried in CS3 yet) what is what.

The only difference is that you have to hold the Alt/Option down.. For me, beats the tar out of quitting the Curves and going to Threshold, using the eyedrop tool, then leaving Threshold and FINALLY going back to Curves..

You gotta try CS3, it's SOOOO much better....

DavidTO wrote:

Dragging the end points in levels does not use the black/white point settings, AFAIK, it just moves the black point up or the white point down.

Dragging never does (it shows clipping, though, in both cases). You have to use the in-dialog X-point tools, which DO use your custom settings (if any), both in Levels and Curves...

Mike Lane

Nikolai wrote:

You gotta try CS3, it's SOOOO much better....

I have the CS3 web premier version. Photoshop CS3 is far, far superior to cs2.

DavidTO

I've tried CS3, just not the option-drag in curves.

Nikolai

DavidTO wrote:

I've tried CS3, just not the option-drag in curves.

Option-drag was the same in CS2 (and, IIRC, in CS, dunno before that, I started with CS).
CS3 added check box for persistent clipping display (and a lot of other things you're definitely aware of, like color-coded curves, compo display, etc.)

DavidTO

Nikolai wrote:

Option-drag was the same in CS2 (and, IIRC, in CS, dunno before that, I started with CS).
CS3 added check box for persistent clipping display (and a lot of other things you're definitely aware of, like color-coded curves, compo display, etc.)

Yeah, I don't like the representation as much in curves as Threshold. I find Threshold more precise. And having remapped the commands, they're both just a keystroke away! But one thing is definite about PS: You can do anything many, many ways.

wxwax

I tried it last night and it works a charm. The video itself is color borked, can't make judgments of the process based on the appearance of the image in the vid.

I like this method, I find it easier than the Alt-curves method.

Sam

Thanks Sid!!!!

Sam

SitterS

Finding the grey point is also talked about in Kelby's "CS2 for Digital photographers".

Shane