An art instructor who charges for his courses is using one of my photographs in his class. All the students including himself have painted the photograph and he has posted his painting on his site. I did not give permission to any of these people to paint my photograph. This is my most popular photograph which I sell in many shops in the area (I live in Canada). Is my copyright infringed and what can I do to remedy it?
This may well be infringement, but I agree that you should start by reaching out to the instructor. You don't want to pay a lawyer if the matter can be be adjusted peacefully.
In the US there is a special limited exemption to copyright for "use in classroom instruction" which might apply in such a case. I am not sure if there is a similar provision in Canadian copyright law. But the instructor is likely to change his practice if you notify him of your objection, even if he has the technical right to use the photo. At least it is worth finding out. If he won't, then you can always consult a lawyer.