Macro photography opens up an entire world of opportunity for the creative photographer. Armed with extension tubes, close-up diopters, and teleconverters the nature photographer can explore hidden worlds unseen by the average person. Flower stamens become abstract washes of color while tiny insects reveal drama in unexpected places.

Of course, macro photography offers its own challenges. Principle among these is limited depth of field. At life-size and beyond, depth of field can be so reduced that even small subjects can't be recorded in complete focus. A butterfly's body, for example, will be in focus but the tip of the wings will not. Traditionally, limited depth of field is dealt with through the use of electronic flash, which permitted the use of tiny apertures. While flash does work, there are many situations where this is not an ideal option. Wary subjects or limited space create the need for a creative solution.

Several years ago I decided to experiment with digital and see how it could be used to overcome the depth of field limitations of macro. The solution I hit upon was to merge multiple images together into a single composite image. Similar to merging two images with differing shadow and highlight detail, I merged multiple images, each with a different focal point. Layer masks were then used to selectively reveal the in focus portion of each image (For an overview on using layer masks see Mastering Layers).

To demonstrate this process, let's walk through the steps used to successfully photograph a hibiscus. The images were captured during a photography workshop I participated in several years ago. I have always been a fan of hibiscus flowers and I ventured into the garden with the hope of capturing the flower's beauty and detail. Towards this end, I mounted a close-up diopter on my 70-200/2.8 lens. For stability I used a Gitzo tripod while the wind was neutralized with a plamp. Once the setup was complete, I realized three things.

First, while the plamp did hold the flower relatively still, the breeze (caused by the appearance of my camera no doubt) still produced a slight shiver in my subject. Second, the soft, overcast light was much more pleasing to me then anything I might produce using a flash. Third, and probably most important, my flash was sitting back in my hotel room instead of in my camera bag. These three factors all worked together to force me to come up with a creative way to increase depth of field.

My solution was Photoshop. Using the computer, it became possible to create an image that more accurately reflected reality then a traditional photograph could. I began with a shutter speed/aperture combination that would freeze the flower's slight movements. The cost, of course, was depth of field. Next, I locked down my tripod head and manually focused on the forward edge of the flower. Following the first image, three additional shots were recorded, each with a slightly different point of focus. The second image, for example, was focused on the back half of the foreground. The third and fourth images continued this process, covering the entire flower from front to back. In the end, I had four images that, when taken together, recorded detail in the entire flower.

Next, all four images were loaded into my preferred RAW converter (Capture One) where all conversion factors (size, white balance, file format, etc) were set to identical values. Failure to perform this step would have resulted in slight color shifts between the images (a consequence of auto white balance) and greatly increased the amount of subsequent work. Attention to such details ensured that the images would merge together seamlessly. The images were then converted and brought into Photoshop.

Once in Photoshop, all four images were opened and dragged onto a single canvas (holding down "shift" and using the move tool ensured that each image was centered). Since the camera's position did not change between shots, all four images aligned perfectly with the one below it. I like to keep myself organized as I work, so the images were stacked in order based on their focal point (sharp background on top and sharp foreground on the bottom).

With the images stacked, I added layer masks to the top three layers. Each layer mask was then painted black, hiding the layer, so that only the bottom image was visible. From there, I accessed each layer and painted white on the layer masks to reveal the sharp portions of each image. By gradually fading from one layer to the next I was able to provide a seamless transition, creating the illusion of a single image with detail throughout.

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Chris Gamel has been an active wildlife photographer for the past 14 years. The combination of his biological research and photographic interests has taken him around the world. In 2001, Chris discovered the joys of digital photography and he hasn't looked back. Chris lives with his wife and daughter in Salt Lake City where he teaches courses at Weber State University and Salt Lake Community College. To see more of Chris's photography, visit his web site at www.Animal-Antics.net.