Hope all is well with you. Collaborations with professional photographer in exchange for free stays can be worth it if the photographer’s work is excellent, do due diligence. I had potential guest who offered the same for free stay, I asked for his portfolio and to book 1 night and willing to give him free additional night but did not proceed. Best of luck Linda
Maybe turn it around and say you can book, pay the normal price, do your photos and I'd be happy to purchase the ones I want. Sounds like someone looking for a free stay to me.