Sun 10-Mar-13 11:46 AM | edited Sun 10-Mar-13 12:03 PM by Leonard62
Marty covered this issue pretty well. My response would be a little more harsh. These lenses are a scam in my opinion. To label them professional is an advertising lie. They are targeted to the unknowing novice. Stay away.
edit: The company that makes these Vivitar products is not your father's Vivitar. The company just purchased the name 5 years ago and is not the same company that made the Series 1 lenses in the 80's.