What is it?
The last several years have produced several photographic developments which allow photographers to harness the power of multiple images to break the traditional photographic limitations imposed by single-frame capture. One common example is High-Dynamic Range images (HDR) where several photos, taken at different exposures, are blended together to make a single image which encompasses a broader dynamic range (often up to 20 f-stops) than a single photo can effectively capture.
Enter Photoshop CS4’s new Depth of Focus merge which again, breaks through a limitation of photography, and in the process helps you defy the laws of physics. Macro and close-up photos have always suffered from a narrow depth of field. The closer the subject is to the imager, or film-plane, and the higher the magnification the shorter the range of focus.
The Depth of Focus merge allows you to make several exposures, set to different focal distances (e.g. near, medium & far), and merge the in-focus sections from all three to expand the depth of field beyond what any lens can capture with a single image.
Why is it important?
The ability to control focus has always been important for photographers. Focus, and depth of field, plays and artistic and compositional role in architecture, food, advertising, fine art and landscape photography. While photographers have long been able to limit the depth of field by selecting a wide-aperture and shooting wide open, they have not been able to exercise such precise control over extreme depth of field. All lenses reach a point where they are unable to achieve sharpness in the very near and very far. By blending multiple images, photographers can now achieve infinite depth of field for macro, close-up, landscape, architectural or product photography.
Bonus Tip: When working with macro photos, be sure to take more photos (in-focus slices of the scene) than you think you’ll need. I’ve created a tutorial to help you use the Depth of Focus blending from Lightroom and Photoshop.
This was very helpful, still not sure about depth of field. Is it only where the background is faded out or where the background is in full focus just as the main thought is???
Gayle,
Thanks for your comment. Depth of field is a measurement of what in the original scene is in focus in the completed picture. Imagine you have a camera set on a tripod and posts positioned at five-foot intervals from the front of the camera’s lens. With a shallow depth of field, only one post would be in focus and the rest will be out of focus. With a long depth of field, several posts will be in focus.
Depth of field is adjusted by changing the aperture on your camera, your lens selection and the size of your camera’s sensor. Adjusting depth of field is a creative tool for photographers to use to help tell their story.
Jay