Today’s Question: Can you explain a little about the Highlight Priority, Color Priority, and Paint Overlay options in the Post-Crop Vignetting setting [in Adobe Camera Raw and Lightroom]? How do they differ?
Tim’s Quick Answer: The Highlight Priority and Color Priority options are very similar, enabling you to have bright highlights overpower the vignette effect. The Paint Overlay option causes a simple black or white overlay, which carries the risk of having areas with the vignette effect appearing very muddy.
More Detail: In theory the Highlight Priority and Color Priority options for the Style popup in the Post-Crop Vignetting are slightly different, but in actual practice you likely won’t see any significant difference between them. The Color Priority option ostensibly preserves more natural colors in the vignette areas, while the Highlight Priority retains higher saturation. In practice, the difference between these two options tends to be extremely subtle.
The Paint Overlay option will produce a result where either black or white (depending on whether you’re darkening or lightening with the vignette effect) will create an overlay at the corners of the image. The result is a relatively muddy appearance in those areas, which I personally find is not a pleasing effect in most cases.
With both the Highlight Priority and Color Priority styles the Highlights slider will be available once you have applied a negative (darkening) value for the Amount slider for the Pont-Crop Vignetting effect. When you increase the value for Highlights, any bright (highlight) areas that have been darkened by the vignette effect will be brightened up to “shine through” the vignette.
A somewhat extreme example of the value of the Highlights slider would be having the sun at the corner of the frame. The vignette effect would darken the sun to some extent, but you can brighten it up again to have it “overpower” the vignette effect by increasing the value for the Highlights slider. When you have very bright areas of an image being darkened by the vignette effect, this can create a more realistic (and pleasing) result.
I generally use the Highlight Priority option for the Style popup, in large part because it is the default setting and is virtually indistinguishable from the Color Priority setting. I don’t like the Paint Overlay setting because more often than not it tends to create a muddy appearance (with poor contrast) in areas where the effect is applied. In addition, the Highlights slider is not available with the Paint Overlay mode.