I want to let you know that I am not satisfied with this lens because when I took some pictures and noticed there are black surrounded inside the picture that made me wondered if this lens is defective. Then why the black is there in the picture? Can you tell me what is wrong with the lens? That is why I want to return it back to you for refund and if you think that the lens is defective then it means you will pay the postage to send the lens back to you. Please let me know as soon as possible. Thank you for your cooperation in this mattter.