Hi Thanks for your kind comments.a ring flash has two components the 1st part is the control panel which mounts onto the cameras hotshoe and the 2nd part which is the lightening part screws into the lens thread usually via an adaptor which are normally supplied with the ring flash. It was invented by a dentist for taking photos of the mouth. Some people swear by these for macro shots others detest them. I'm sort of in the middle but prefer using an old fashioned flashgun.
I would recommend you get a book called Understanding Exposure 3rd edition and it's by Bryan Peterson. He describes everything in a really simple form and is easy to follow (which I needed).
I took the shot of the butterfly at f22 shutter speed around 200 iso 100. Because the aperture was so small it made everything black then it was only a matter of lighting the subject with my flashgun (off camera).
Hope this helps. Any other questions fire away. regards Graham.
There is nothing worse than a sharp image of a fuzzy concept.. Ansel Adams