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This article is part of a mini-series about the masking features in ON1 Photo RAW and ON1 Effects. This article explains the Perfect Brush, the edge detection feature of the Masking Brush.

What Is The Perfect Brush?

The Perfect Brush is a feature of the ON1 Masking Brush that turns on edge detection. When you are masking around a specific object, edge detection makes it much easier to get a crisp, clean mask without the need for painstaking brush strokes.

How Does Edge Detection Work In The Perfect Brush?

Edges are deleted by differences in color tones. When turned on, the center of the Perfect Brush samples the color at the center of the brush and looks for colors that are similar in tone within the boundaries of the entire brush. Similar colors are included in the brush stroke and dissimilar colors are excluded. As you paint with the Perfect Brush, the brush continually resamples the tone beneath the brush.

In the example used in the video with this article, brushing in the blue sky will not affect the yellows or greens of the flowers. As the colors are very different , the result is a clean mask along the edge of the flower.

Pro tip: Lock the color sampling by pressing and holding the Command (Mac) or Control (Windows) key before starting to paint with the Perfect Brush.

Adjusting The Color Sensitivity Of The Perfect Brush

The toolbar of the Masking Brush has an advanced options popup (the gear menu). There are two controls to fine tune the behavior of the Perfect Brush.

• Color Threshold - set how narrow or wide the color matching of the Perfect Brush is. Smaller numbers mean more precise colors matching.

• Transition - set how quickly or gradually the mask tapers off (similar to a Feather)

I tend to start with a lower Color Threshold and moderate Transition for most of my Perfect Brush work. If the Transition is set too low, the resulting mask can be jagged or splotchy.

Pro tip: Use a small Color Threshold and low Transition when a crisp mask is needed in monochromatic areas of a photo.

Up Next

This masking series continues with a dive into Custom Brushes in the Masking Brush tool.