My son is 5 now. He has never been afraid of Santa. I started taking him when he was a baby and it has always been fine. My dauighter just turned 3. She was very afraid when she was a baby and when she had just turned one year. She has been fine last year and this year.
Find a professional photogropher (not the one at the mall) that has Santa visit his studio and have your picture made there. It costs more but they can take more time. When my dgt was about 13 months old, we did that. The photogropher set up the picture so that the kids were sitting (my dgt) and standing (my sosn) next to a Christmas tree. There was an open "window" in the background. Just before the picture was taken, Santa appeared in the window and waved. My dgt. never saw him so we got a great picture. I had told my son what was going to happen so he would not spoil it. The picture was so good, we actually used it for our Christmas card. After we got the picture, Santa came out and my son sat in his lap. My dgt screamed and wouldn't sit in his lap but we already had a great picture!