One of the niftiest new filters in Photoshop’s bag of tricks is the Iris Blur filter. It mimics the behavior of limited depth of field by blurring the image outside a customizable “iris” shape. As usual, Photoshop provides plenty of options for controlling the radius of the non-blurred area (both an inner “hot spot” and outer "total effect” area), the shape of the iris, and the amount of focusing you want within the iris. Unlike using a wide-open aperture on your camera to blur the background, Photoshop doesn’t “know” which objects are close or far, so you need to craft the shape of the iris yourself. Fortunately Photoshop also lets you add multiple different iris blurs to create effects that would not be possible with a camera…

This image of some Orange Roses taken in the Texas Hill Country is a natural for Iris Blur. Since I wanted to have the roses all fairly sharp, I captured the image with a large depth of field – using f/22, which at 24mm full frame provides nearly infinite depth of field. Then I brought the original image (shown below) into Photoshop, using ProPhoto colorspace to help accommodate the saturated red and orange colors of the roses. The only adjustment I made in Camera Raw was a slight crop, maintaining the original 2:3 aspect ratio.

After a quick pass with nik’s Raw pre-sharpener, I created a new layer to use the Iris Blur (unfortunately the Iris Blur is “destructive” so you need to apply it to a separate layer if you want to be able to get your original image back). Then I simply brought up the Iris Blur filter and added a focus point on each of the roses. I left the closest roses focused at 100%, and de-focused the further away roses slightly.

As I added the focus points, I adjusted the “hot spot” (internal radius) to a size slightly smaller than the rose, and the outer radius to a size that kept the flower sharp but rendered the area around the flower with a pleasing blur. After adding the Iris Blurs, the only other enhancement I made to the image was a quick pass with the nik ColorEfex Lighten/Darken tool to darken the four corners of the image and further draw attention to the center. The final image is the one below: