I have a question about "Native ISO" in the real world and how it relates to color grading. I was shooting 35mm film before all these digital cameras became flat-out amazing practically overnight. Then the goal was always to shoot with the lowest ISO possible to achieve the least amount of grain (unless you were making an artistic decision to get that look). If I was shooting outside plus had a nice lighting package I'd shoot 5201/50 ASA (Daylight) and 5212/100 ASA (Tungsten) 99 times out of 100.
I've recently been shooting a lot with the Blackmagic 4K and have read that its "Native ISO" is 400. Because of my film background this seems counter-intuitive. Yesterday I was shooting for a client and had the camera at an f16 with a 200 ISO. Because of what I'd read, I was tempted stop down to an f22 and change my ISO to 400... but the "little film voice in my head" just wouldn't let me do it. It kept telling me "Higher ISO means more noise... stay at 200 and you will get a cleaner image".
So how does it work with "Native ISO"? Should I really shoot at a 400 ISO every chance I get in order to capture the best image for how the camera is calibrated? Will it really give me more latitude when color grading? Or would I still get a cleaner image staying at ISO 200? I've Googled around quite, but haven't found any articles that answer specifically this question. Would love to hear from someone who knows a bit more on the subject or has a link that could point me in the right direction.
Thanks much.