Looking for tutorial gor grading. RGB Parade and and Lumetri colour wheels

What values should I set my image to?

Well now, this is a different discussion than the one about basic tool functions. Because tools exist to help us get something done. To get from here to there.

But ... what "there" should I get to? How do I know?

It ... depends!

Yea, not that helpful.

What about black and white points?

This depends on the needs of the image. Very typically colorists will set the black point to between 2-7, maybe as high as 10 nits on the left-side scale of the RGB Parade or Waveform. (Using the 8/10 bit scale option, lower right corner of the Scopes panel.)

This is to ensure that no shadow values become "crushed", driven below 0. Remember, no matter which frame you are on of a clip, there may be other frames with lower or higher black/white points than the current frame. It's good to allow a little leeway here.

Sometimes the shot needs to be harsh or dark, and so pushing the blacks down may be justified. And sometimes there shouldn't be a total black in the image. And the black point might be around 10 nits.

The same with white points. Setting clear to 100 leaves no room for the natural frame-to-frame changes of values through a clip. And also may likely be too bright for most scenes. So setting the white point to something 80-ish or above is "probably" useful. But you will need to set this per image.

Some Color Basics

Start by getting neutrals truely neutral in the Vectorscope. Generally, you want the 'neutrals', the gray/white/black tones, to be centered in the Vectorscope. But that is just ... generally. Because some times you do want a bit of a color cast to the image, whether warm or cool.

For most color work processes, it is easier to get things to as close to near-neutral as possible as the first step. This makes the process of matching the images in the shot-to-shot progression through the sequence so much easier.

Then, after the steps of neutralizing and shot-matching, applying a 'feel' to the scene or a group of shots will be both faster and give a more uniform look and feel.

Neil

Well, hello there!   😉

You've got the first part, as you know that the wheels are what are technically called Lift, Gamma, and Gain. They function purely like that if you've read any colorist's tech manuals.

Wheel/Slider Action

For each of the three wheels, the wheel is the color (chroma) control, and moves about the base color wheel model. The slider is the "brightness" (luma) control for that segment of the image. So you work brightness with the slider, color with the wheel center control.

Both of these types of controls are fairly general tools: they move all color or tonal values in the image towards whatever direction you move the control point from the center. And though each tool has more effect in the listed range of the specific control, it will have some effect over the whole image unless you counter with a different control as discussed below.

And to really get to understand how the controls work, it's nice to have say a gradient ramp as your image on the screen. You will get a better feel for where, and how much, each control affects the image.

Plus it's good to have the RGB scope up at the least. I normally have three scopes up at once. As I normally have the Waveform YC no chroma up for simply checking luma values, detect contrast "bunching", and for general image evaluation.

But some people really prefer the standard RGB waveform, as  where it's white, there are equal amounts of the three channels, where it's colored, there are unequal amounts. Which also gives information on the image. And can be useful for matching image white/black points.

I also typically have the Vectorscope YUV up, for two reasons: to see where and how much color there is, of course, and also, to check the neutrals of white/gray/black, which normally should be dead centered on the two crossing lines.

Shadow Wheel/Slider

This as noted above is a classical "Lift" control. For quick example, grab the luma slider and note how you directly place the bottom value by lifting or lowering that slider. And of course this is used to set black points for the image.

In action, this is fairly similar to grabbing the bottom of an RGB Curve and moving it around. You will get the most effect close to the bottom of the image (0-100 scale), very little towards the top. Yet, note, this does have a small effect clear to the top of the image.

The Wheels or chroma control will have an effect similar in "area" of the image to the luma slider. And is useful to modify the general color tones of the image.

Mids Wheel/Slider

This is a classic "gamma" control. It affects the middle values more than the two ends, but it does have some effect clear to both ends of the scale. It can be a quick tool to set the general "brightness" of the image (luma slider) and warmth or coolness (chroma wheel).

In action, this is like setting a control point in the center of the RGB Curves tool, and moving that about.

Highlights Wheel/Slider

This is a classic "gain" tool. It will affect the upper end of the scale the most, but will have some effect clear to the bottom of the scale. And is of course useful to set the white point.

It is like grabbing the white point end of the RGB Curves tool and moving it about.

Using the Color Wheels/Luma Sliders

Each of these tools will have at least some effect will outside their named area. So to get "targeted" correction requires using two or more tools against each other.

For example: to "lift" the bottom values brightness a bit, but not move the mid tones brightness, requires two different actions:

• "lift" with the Shadows Luma slider
• counter the affect to the Mids luma values by dropping the Mids luma slider.

Targeted work with the LGG (Lift/Gamma/Gain) tools is always a push/pull process. So like with the example above, if you want to cool the Shadows but not the Mids, you push the Shadows wheel towards blue/cyan, and also pull the Mids wheel a little bit in the opposite direction, towards the yellow/red direction.

Essentially, you counter or cancel the mids action of the Shadow tool by moving the Mids tool.

And if you want to warm the mids but not either the shadows or highlights, it takes three actions:

• push the Mids wheel to whichever "warm" hue you want;
• pull the Highs wheel opposite to the Mids to return the highligts to proper hue;
• pull the Shadows wheel opposite to the Mids to return shadows to the proper hue.

Watching the scopes while doing this is very helpful. But as noted above, I do highly recommend also having a simple gradient ramp as the image while testing. So you have a visible grayscale image from 0-100 left to right, and can see exactly where and how much effect you get with any particular control movement.

Neil

@R Neil Haugen 

Sorry about typoes, dont seem to be able to edit post.