Purple Flowers with Backlit with a Sunset
To use this backlighting technique you need to position the camera so that the sun's light is coming from behind the flower. The sun needs to be low in order to do this. Therefore sunrise and sunset works best. Another important thing is to get down to the flower's level.
Getting a Completely Black Background - Purple Iris
I used only 1 flash to take this photo. I used flash to overpower the ambient light. I placed a softbox 90 degrees to the right side of the flower and a reflector 90 degrees to the left of the flower. I made sure none of the light spills on the background to ensure a complete black backgrou