Split-Toning is there a Preferred Method?

[xpatUSA]

Split-Toning: namely creating a two-color image where the coloration depends on image luminosity - one color for darker - one for lighter.

I've read of three different ways using Layers and Masks and there may well be more ways of skinning the proverbial cat.

A common element is to convert a base layer into grayscale and then to use it and it's inverse as Masks. But one method then puts a filled color Layer above a grayscale image, another below and a third colorizes the grayscale image itself.

The question remains ... is there a Preferred or "best" Method for Spilt-Toning?

Question prompted by my mentions of Teal and Orange colorizing here.

Ancillary question: are there other ways to skin the cat e.g. not involving Layers?

[xpatUSA]

... and a third method colorizes the grayscale image itself.

For example said method according to Pat David seems to work well:

[Manfred M]

All kinds of approaches here Ted.

These techniques are all used in a process called "Colour Grading" and these come out of cinematography originally. If you watch an old colour movie from the film era and read about "color timing" or where a "color timeist" is name, this is where the colour grading occurred in changing the times and temperatures in the film processing steps. Colour grading is really a digital technique.

I don't know if GIMP has this functionality, but can confirm that Photoshop and Affinity do. I seem to remember this was also a feature of a relatively recent Lightroom release.

A long time ago, when I first learned this technique, the standard approach was to use pixel based editor, but parametric editors may have this functionality as well. Traditionally a curves layer and to apply a colour bias on one of the colour channels for the highlights and to do the complementary colour for the shadows. Carefully said, there is no clear technical definition for either term (i.e. what is a highlight and what is a shadow). Blending modes are sometimes used to enhance or tone down the grade with "Screen" blending mode applied to the highlights and "Soft Light" or "Screen" blending modes used with the shadows. Intensity can be controlled by applying varying amounts of opacity.

The other common approach is to use a colour lookup table (LUT) to apply the grade. Not surprisingly LUTs are found in both Photoshop and Affinity and one can either use the pre-packaged functions or get LUTs on the web. The LUTs from the web are primarily targeted at the "pro" video editing software like Adobe Premiere Pro, Apple Final Cut Pro, Avid Media Composer, etc are the primary targets here. LUTs are very easy to use, hence their popularity.

I don't use these techniques very often, so I'd have to go back and play with them to refresh my memory.

[xpatUSA]

Thank you, Manfred. More to it than meets the eye, eh?

[Manfred M]

Thank you, Manfred. More to it than meets the eye, eh?

That is one way to put it...

At one point there were some guidelines on how to determine how to grade (colour harmonies were an important driver) and being subtle was one of the overwhelming drivers, We are into a free-for-all where we get some rather over-the-top approaches that you have pointed out in some of your examples, where every film or TV director is going for a unique "look" for the production. Some are incredibly good, but quite a few rely on blunt force.