Here in the Dallas Area, camellias need shade starting at 11am-12pm. Further up north, you can probably exceed that. If the plant gets too much sun, those leaves in direct contact with the sun will start to brown out.

I use drip irrigation and have placed a dripper right close to the main stem of the camellias. Then as they grow, I add more tubing around the plant in order to water roots further away. My tubes have other drippers, about every 12" in both directions. They are set to run for 1 hour (equates 1 gallon of water) most of the year, except now, when I run them for 1.5 hours because our daily temps are in the 100-110s through September.