I have seen the various charts and "official ratings" , but have found they vary in minor to significant degrees from what one will find by exposure tests on one's own individual camera or cameras. I'll admit that It seemed puzzling until I was made aware of the phenomena of "process variance /process excursions" and subsequent "performance variance" that have plagued the semiconductor production iindustry from the time of Shockley's first publication on the topic in, as I recall, 1960 or '61 up to the present day. A study of the history of those phenomena disabused me of the idea that our cameras' image sensors were highly refined devices that deliver Dynamic Range within strictly defined limits.
Anyone willing to personally test the raw-accessible dynamic range of a number of cameras, including multiple cameras of the same brand and model will discover, as a number of us have, that there is considerable variation in the upper limit of DR delivered by ostensibly identical sensors. The camera manufacturers assure that their sensors will deliver at least the DR necessary to at least blow out highlights of JPEG files, but seem uninterested in how much more so-called "headroom" their sensors will deliver. That, of course, makes providing an in-camera raw histogram a pricy option evidently not-to-be-considered, what with how it would boost the per-unit price and all!
What amazes me is that so few have actually done the due diligence of conscientiously testing their cameras for the actual raw-accessible DR they can deliver. It's not hard. certainly not beyond the capabilities of those likely to be participating in these fora. They just need to do it. Testing my own cameras and those of friends, and participants in classes, courses, and workshops, I've personally seen a range of of extra raw-accessible DR of from 2/3 stop to two and 2/3 stops, with the great majority of cameras having at least one full stop of unused DR. There are rumors of some cameras with three stop or more of unused DR.
But even one full stop of extra DR is nothing to sneeze at. Failure to use it in raw image data capture results in forfeiture of up to 50% of tonal and chromatic spectra..or more, depending on scene DR. You all should be able to figure out what that amounts to depending upon 12-bit-depth vs. 14 bit-depth.
Best regards,
Dave