Yesterday, I discussed how-to use Photo-merge in Photoshop CS4 to create a panorama. Well, you can also use Photo-merge to increase the depth of field of a photo. In macro-photography, depth of focus can be very narrow. Photo-merge will allow you to take multiple photos at different focusing depths and combine them together.
1. Take a series of photos focusing on different depths
In the image on the left, the pistil and stamen are in focus. In the image on the right, petals are in focus. These two images were hand-held, but that’s ok with Photoshop.
2. Open Photoshop and use Photo-merge
Start with Photoshop CS4 with no open documents. Go to File > Automate > Photomerge. In the Photomerge dialog box, use the Browse button to find the photos to be merged. Use the default Layout set to Auto to start.
3. Let Photoshop create the photo-merge
As part of the photo-merge, Photoshop will automatically align the images, blend the images and fix color shifts. Each image on its own layer using masks to produce the complete image. But, if you look at the bottom petals of the Stargazer, they are out of focus. Photoshop used the wrong photo for that part.
4. Delete the old mask layers and create a new one
Photoshop properly aligned and blended the colors of the two image. But, I can merge the images better by hand. I deleted the two masks that Photoshop created. The top photo is the one with the sharp stamen and pistil. I added a blank mask to this layer with a pure white fill. Using a large soft brush, I drew over the stamen and pistil in the mask layer with pure black to reveal the sharp image.
5. Final composite image
With the sharpest parts combined into one photo, I cropped the image to accent the best part of the Stargazer. To further enhance the composition, I created a selection around the flower and blurred the background to remove any distraction from the flower.