Lately, I have concentrated my photography on landscape and critters so much so that I have rarely taken any flower photographs or done any macro photography. Flowers are among my favorite subjects to photograph and macro photography is something that intrigues me. I was thrilled to learn that my latest photography challenge was to put my Nikon D850 to the test by using its in-camera Stack Focus feature.
With macro photography, the depth of field is so small so that only a very tiny portion of a subject can be in focus in a single photograph. The beauty of Stack Focus (also known as focus staking) is that some software will combine photographs with different areas of the subject in focus into one photograph so that the entire subject is in focus. The painstaking agony of manually moving the focus point to ensure that every portion of the subject is focused on is daunting, time consuming, and subject to inexactness. The D850 takes care of that by itself. It will automatically move the focus point for you as it takes a preset number of photographs. When all the photographs are taken, the photographer uses software to combine them into a single photograph with all of the subject in focus.
I set up a black velvet background and used three flashes, one on either side and one at the bottom of the flower for illumination. I set the camera to manual mode, the shutter speed to 1/60, the f-stop to f/8 and the ISO to 64. The flash output was set to 1/128.
Once the set of photographs was taken. I had to review them to determine which of the 100 or so shots I needed to composit a single photograph with all of the subject in focus. A quick review of the photographs revealed which shots would have the most depth of focus. There are several application programs that specialize in focus stacking but I chose to use Photoshop. I first opened the 35 to 50 photographs, depending on the preset number of images, in Adobe Bridge, then selected the Tools menu and under Photoshop, selected the “Load Files into Photoshop Layers.” From there all I needed to do was align the images and blend the images. This was the most time consuming part of the process although it was just a single click for each item. The memory capacity of the computer and the availability of memory for the scratch disk that Photoshop needs to operate efficiently can slow things down if there are other demands on the memory. But, eventually, I got it done.
This is a spray of Hydrangea flowers. If I had taken just one macro image, I would have had to focus on one area of one flower and the rest of the flowers would be out of focus. With focus stacking, the entire spray is in focus. The process took about an hour from setup to finishing. It takes just a few minutes for the camera to take the images. It took me a while of fiddling to set up the flower and adjust flash output. The rest of the time was downloading and processing the images in Photoshop. And, to see an entire image in focus like this, it is like magic!