About artificial backgrounds: To do a really good job with an artificial background, the iris should be selected and made into a separate layer. (I use Photoshop). At that point, one can use anything for a background. An example from one of my ads is attached. It is a somewhat tedious process, taking about an hour to carefully trace the outlines of the flower. I've found that shortcut selection methods don't meet the standards needed for publication. I usually only do this when the original background is unsatisfactory- something distracting or unattractive. I think Brock's ideas about creating a good background with the camera are excellent.
My theory about the truth of photos: By stopping a subject in time, a photo gives a different impression than we get with our continuous perception. A good example is: when taking a number of photos of a beautiful woman, there will always be a few in which she does not look at all beautiful. But it is a true image. The difference is that when we see her "live", we get an overall impression in which those less flattering angles become unimportant. And yes, when we select a photo of an iris to share, we should check to be sure it matches our overall impression of the flower.
It's way above my ability, I'm afraid. But I'll ask anyway. Does that background have to be black? Would the program substitute other colors in lieu of black? I'm asking because when looking at the colors on my monitor after taking a photo it's more important to me that they display accurately. More important than being pretty. The perception of what you see can be altered by the background color. So using green, gray, white or other colors in addition to black could shift what the eye perceives to a more accurate representation of what you actually see using the naked eye. Photos are strange things. They can fail miserably for catching some things; or they can enhance details out of proportion to what the blooms really show. I wouldn't say they lie exactly, but the truth is certainly altered sometimes.
Texas Zone 7b, USA