Over the past couple of weeks, I’ve been photographing some new prairie wildflowers for me … the Downy Gentian. These wildflowers are a very deep blue and very mesmerizing. And in some conditions, the flowers look nearly purple. All the Gentians I’ve been finding are quite small, ranging from about 8-inches to 16-inches tall, and are quite well hidden at the foot of other, taller prairie plants.
On my last trip to Snowball Hill Prairie, I found lots of these beauties. In some places, it was very difficult to walk without stepping on them!
Being so low to the ground, it was very difficult to photograph them in sharp focus, while throwing the background out-of-focus. So my next step was to shoot a series of images for focus-stacking. When shooting for focus-stacking, I always try to shoot at a very wide aperture (f/3.5, the maximum on my macro lens), and vary the focal point on the flower, from front to back, until the entire plant is captured. The result, when these images are combined, gives a very shallow depth of field that renders the background out-of-focus, thus placing emphasis on the sharp flower. Here is one focus-stacked image I captured, after combining 13 individual images:
To compare the focus-stacked image, below is a single image of the same plant, captured at nearly the same composition. Even with the background not in sharp focus, note how the background is much more in competition between the subject and the background:
I have read that Missouri has 7 genera, with 13 species of Gentian, so I’m not positive which species I am seeing. But I suspect it is the Downy Gentian. The photos above look like the closed, or Bottle Gentian, due to the flowers being closed. But in the following image, you can see that the flowers do open:
Photographic Equipment Used:
- Canon 5D Mark 3 body
- Canon 180mm f/3.5 macro lens
- Bogen 3221 Tripod with ballhead
- ISO 500
- Aperture f/3.5
- Shutter 1/125 sec. and 1/2000 sec. (bottom image)