Week 1, Example 5 Solution

This is an unusual image in not having a shadow, highlight, or neutral. This means you cannot set a valid shadow or highlight. There are also no gray objects in this image, so you cannot set a neutral. So for this image we will rely on the threshold control in Lab mode.

In RGB mode, if you were to click on one of the yellow flowers and set a highlight there, the whole image would take on a blue color cast, because the brightest object will be forced to be white. In order to be used as a highlight in RGB mode, the lightest important object in the image must be a neutral color.

Because there are no neutrals, let's use Lab in threshold mode to set the shadow and highlight.

On the right, you can just see some of the leftmost yellow flower going to maximum brightness. We stop there because we don't want to blow out the detail in the flowers.

For the shadow threshold, we'll move in a bit more agressively, allowing some of the background to go to areas of solid "black", concerning ourselves only with the darker areas of the buds at the top and upper right of the image.

One interesting note - Lab will retain an object's original color even if you make as light or dark as possible.

Now let's try the same thing in RGB. The image on the right shows the result after setting the shadow and highlight. Notice that we couldn't come in as far with the white threshold. This was because we started getting bright dots almost immediately in the yellow flowers. Still, this does not look bad at all. RGB is holding its own here.

It's hard pick a favorite by looking at these screenshots. I suggest you load the [original image] and try this yourself and decide.