Originally posted by Alex645 Youʻre wise not to try to do more than two islands. They are all unique in their own ways and your days (and nights) will be full just on Oahu and Kauai. Hawaii (aka The Big Island) is larger than all the other islands combined and Kilauea erupted and has been active since 1983 and there is no sign Pele will stop....so youʻve got time to come back and see that again one day.
Madame Pele is very finicky. I was on the Big Island (now Hawaii Island) several years ago and got some fun shots, bobbing off the coast, of lava flowing into the ocean at sunrise. This year I just missed the flow and only go to see partial glimpses of flowing lava so yes you might have to go back.
My 16-50 was water proof enough to withstand a very bouncy ride on a rigid hull inflatable down the Napali Coast and the 50-135 got drenched by back wash while taking pictures of the lava, but my k5, 50-135 kept on going.
Back on topic, my minimum kit for Hawaii is Rokinon 10 for landscapes. 16-50 for landscapes and walk-around. 100 macro for flowers and geckos.