This is the second of a two-part column about creative blur techniques. Inducing blur in a sharp photo seems counterintuitive, but it’s incredibly useful for guiding the viewer and eliminating distractions. There are several powerful digital tools that help you manage blur with precision. In this column, we explore Photoshop’s Smart Filters, Blur Tools and Blur Effects.
Smart Filters allow you to change the settings of filter effects in Photoshop at anytime, providing a significantly more flexible nondestructive file structure. Smart Filters can only be applied to Smart Objects. Convert a rasterized layer or group of layers to a Smart Object by highlighting it/them and going to Layer > Smart Objects > Convert To Smart Object.
You can do many things with Smart Filters—switch them on or off, change their Opacity or Blend mode, mask them or combine multiple filter effects (you only get one mask for all of the Smart Filters applied to one Smart Object); using Layer Blend If sliders isn’t one of them.
Use Smart Filters sparingly, as the price you’ll pay for this flexibility is a significant increase in file size, as much as four times, which slows processing and saving time—but don’t write them off because of this.
Blur Tools filters—Tilt-Shift, Field Blur, Iris Blur—offer simplified interfaces, easier filter setting selectivity (though limited to hexagonal iris shapes), stronger intensity and faster performance than the Lens Blur filter. Not only can these filters be easily applied as Smart Filters, but they’re best applied as Smart Filters; apply one filter, and two new palettes will appear, Blur Tools and Blur Effects, which can be further adjusted in the future if the effects are applied as Smart Filters.
The Blur Tools palette allows you to activate one, two or all three of these filters and adjust the sliders that control each effect. The Blur Effects palette offers three sliders: Light Bokeh (this slider brightens bokeh effects), Bokeh Color (this slider increases the saturation of affected areas) and Light Range (this slider adjusts the range of levels affected, allowing you to target effects into shadows, midtones or highlights—more effectively than Lens Blur’s Threshold slider—and it intensifies the tonal range between the sliders, producing a more realistic effect).
Sooner or later, you’ll wonder how applying a filter selectively through its controls is different than applying a filter to a duplicate layer uniformly and then adding a mask. Sliders that provide selective application of an effect offer variable intensity, blurring an area more or less, while a layer mask selectively reduces the opacity of a uniform effect revealing the focused image below. The effect produced by these two methods can be significantly different. It’s the type of selectivity, not the quality of the blur, that differentiates the Blur Tools filters from one another. Field Blur produces an overall effect. Iris Blur adds selectivity through a radial gradient. Tilt-Shift adds selectivity through a reflected gradient.
Each filter has a blur ring. The central point controls the position of the effect; the outer ring dynamically adjusts the Blur slider. Pins can be used to place additional blur rings with overlapping fields of influence that will feather into one another gradually, making it easy to apply different filter settings to different image areas.
Radial Blur surrounds each blur ring with a second larger double ring. The outer line can be used to adjust the size of the blur field, and it has one square radius roundness knob that makes the field rounder or squarer, and four outer ellipse points to adjust the shape and angle of the radius field. Between the outer line and the center double ring are four inner ellipse points that control the gradient effect between the center and the outer ring; dragging one point will move them all equally unless you hold the Shift and Option/Alt keys to control a single point.
Tilt-Shift adds a reflected gradient with two solid center lines that define a region of clarity between them (the center points on them control rotation) and two dotted outer lines that control the gradation of that region of clarity into blurred areas.
You can easily combine Iris and Tilt-Shift blur effects, as the pins interact with each other using the same Blend mode (similar to Multiply) that adds the blur radius fields from each effect, as well as the areas of clarity. Where there’s an overlap, the clarity is preserved.
To customize blur effects even further, you can apply filters multiple times at different settings and in different combinations. This field is rich with possibilities.
All blurring can cause posterization. Guard against this by checking at 100% screen magnification. Often, posterization can be cured by adding small amounts of noise.
(See my column on adding noise on the Digital Photo Pro website at www.digitalphotopro.com/technique/revolution.html.)
John Paul Caponigro, author of Adobe Photoshop Master Class and the DVD series R/Evolution, is an internationally renowned fine artist, an authority on digital printing, and a respected lecturer and workshop leader. Get access to a wealth of online resources with his free ennews Insights on his website at www.johnpaulcaponigro.com.