This actually confuses me a bit more. Assuming that Nishita sky does a realistic job of simulating a clear sky, I took an indoor scene and lit it with Nishita sky and then used a sun lamp to reproduce similar lighting to figure out how bright the 1 unit of sun within Nishita corresponds to the units of the sun lamp. I came up with about 120, not 1000 as stated on that documentation page. Thinsoldier's Sketchbook 2022 - #5 by thinsoldier
Also exposure can be set in both Film and Color Management. Which one should be used when and why? Why does one default to zero and the other default to one??? The exposure under color management can be adjusted without rerendering so it’s extremely tempting to use that one 100% of the time.