Hi Marcy; thanks for the comments. there is no real secret. This shot was taken as follows:
1. I set up the dandelion in a sun room in front of a piece of black card. I chose the sun room as we have floor to ceiling windows on 3 walls. Lots of light and no really strong shadows, as although it was bright it was quite cloudy.
2. I was using my Canon 10D and a 100mm macro lens.
3. I set up the tripod about 18in (450mm) from the subject.
4. I made a point of setting the white balance on the camera to custom mode, using a piece of white card, to avoid colour casts.
5. I set the ISO rating of the camera to minimum (100 ISO) to minimise noise.
6. I metered off my palm, using fully manual mode. I chose a narrow aperture to ensure front to back sharpness.
7. I shot only one take, in RAW. I used a remote release as the metering called for 0.3 sec exposure at f/16.
8. Back on the PC I made 3 adjustments. I altered the levels to improve the blacks and whites (did not need to do much). I used the unsharp mask to improve the sharpness and also cropped to the 10x8 ratio which I prefer.
I hope this is helpful; I was pleased with the outcome of the shot.