I want to write a blog post about a local art exhibit that’s opening in my town next week. I’m hoping to take pictures at the opening, but I’m sure I’ll end up with copyrighted works from the exhibit in the backgrounds of my photos. Do I have to get the gallerist’s permission for that artwork?
Cultural reporters often face this problem in one form or another. The work they comment on is almost always copyrighted, and while sometimes it is the object of comment, sometimes it just pops up in the story. (Think, for instance, about the reporter who's at a rock concert.) Luckily, it sounds like the situation you’re describing falls under the first principle of the Set of Principles in Fair Use for Journalism, regarding the incorporation of copyrighted material captured incidentally and fortuitously in the process of recording and disseminating news. Using this principle, you can answer for yourself if your uses fall under fair use. The principle lays out three questions for you to consider, which I'm adapting to your case:
• Have you at any point made an agreement with the gallerist, the artists, or anyone else that you would not photograph any copyrighted artwork? If you did, that could override your fair use rights.
• Is the work merely part of the news you're covering, or are you focusing on it? (It still might be a fair use if you focused on it, but you'd use a different principle in the Set of Principles to reason about your choice. This one is about capturing material incidentally or accidentally.) It sounds like it'll just be part of the scene, which is the news you're covering as a reporter.
• Were you expecting to create reproductions of the artwork with your photos, for distribution? It sounds like you're expecting merely to create a news report about the gallery opening.
If you do decide that your uses are fair, then do one other thing. Where you can, give credit (attribution) to any work that is significantly visible in your photographs -- but as a matter of courtesy and ethics, not law.
By the way, the next time you face such a situation, it's going to be so much easier to run through this reasoning process in your head. By the third time, you'll be a fair use pro.