Here's my 2 cents: With a wide angle, dof is usually fine at f8 with a 18 to 28mm lens with a wider lens like a 10 to 18 you can almost always get away with f5.6 or wider if you can afford that fish-eye glass. Even at an iso of 100. I suggest you practice and remember, it's better than carrying around a chart that you always have to refer too! The more you stop down and use the tripod the more in focus "all will be"!
Nikon/Camera systems; Calumet 4x5 field & mono rail
Got tent will camp, got kayak will float, got bride will love!