I've begun to build my teaching examples this winter with trips to three greenhouses - the Liberty Hyde Bailey Conservatory at Cornell University, the plant production greenhouses of the US Botanic Garden and a wonderful orchid exhibit at the Hirshhorn Museum of the Smithsonian in Washington.
So, let's begin at the Bailey Conservatory with a luscious cluster of Bougainvillea. I see them as a group of happy ladies, smiling for a group shot. Greenhouses are typically pretty cluttered. After all, they are not art galleries. For this portrait, I used a tripod and put the camera on a shutter delay. After triggering the shutter, I quickly positioned a piece of black cloth to simplify the composition.
Again at the Bailey Conserv-atory, I selected a Passionflower as a subject. The red is bolder and the flower itself is pretty fancy. It seems to me like a masked male figure on a Mardi Gras float. Now, there was a metal rod on the left edge, and I could not get the black cloth between it and the flower. The solution was to take a dead stalk and wrap it around the rod. That is the yellowish stalk along the left side. It looks natural, and being out of focus, it doesn't pull much attention from the masked person.
For both of these, I shot in manual so the predominate dark tones didn't push the exposure too bright.
At the US Botanic Garden, the challenges were greater. It is a production facility open only once a year. Moving any plant is out of the question, and tripods are not allowed. A black cloth was not possible.
The large single bloom orchids are, to me, straight captures of human faces. Yellow is bright and cheery. The orchid seems to be smiling with a little tilt of the face. The tilt seemed to add a little engagement with the viewer. I got low and shifted around until there was a uniformly bright background. It was a sunny day, so I kept a polarizing filter on the lens to reduce the shine on the flower and leaves.
The Hirshhorn is a museum of contemporary art and culture, so their exhibit Orchids: A Moment is a welcome acknowledgement of the artistic character of nature, and especially of these highly sensuous flowers. The plants are rotated in on a weekly basis to ensure that all are at peak condition. The display is clutter-free; I was able to create clean portraits without greenhouse clutter.
Another orchid captured my imagination as a noble personage sitting for a portrait. The flower is angled away just slightly to reveal some curvature that suggested depth in a two-dimensional medium.
Often I see various lady's slippers standing in a cluster that suggests a family portrait. I see the lower petals as tresses of hair and the top one as a bonnet. These are --by my interpretation-- the Three Sisters. A key action for this situation is to use a smaller aperture so that all three are reasonably sharp. I typically focus on the closest bloom and adjust the angle, so that the back flower is not too distant, and make sure the blooms are not looking away from the viewer.
While my workshop is presented as botanical photography, it is reasonable to gain comparable skill in people photography by following two points. First, be able to describe the message in your photo in a simple sentence. (Message: Shelly is a happy and outgoing young girl.) Second, once you have the message formed into a composition, give a lot of attention to the background so that your message does not get muddled by distractions.