Be sure and ask the vendor before taking a picture. 99% will say no. Some vendors won't let you have pen or paper in their booth, thinking you are jotting down pattern info. At Paducah last year one vendor told a woman she was looking at the booth quilt too long. She said she didn't want her memorizing the pattern. Some vendors seem out for money only but most are extremely friendly and helpful. Only shop at the friendly vendor booths. LOL. I always go to each vendor booth and write down what interested me and the booth no. then I made a second trip to the booth to buy. I found I didn't want the item the second time I looked at it. Quilt shows are so much fun and I learn a lot just from looking and I get very motivated. Be sure and have a water bottle with you and headache medicine.
Printed address labels will be a big time saver. Many booths have a prize drawing. I print out address labels with my info including my email address to take to quilt shows.