Can anyone give me a brief understanding of how much Dynamic Range is lost as we raise our ISO? As an example: At what ISO would I have had to shoot the enclosed picture with my Z9 to see a "noticeable difference" if I'm delivering in basic sRGB.
Why are you concerned about "dynamic range" ? Is it a term you heard and now think is important, or have you already had an issue with something that is clearly a DR issue and want to understand or enumerate it?
I don't think that most forum conversation that mentions "DR" is really about DR at all; often people just use it as a proxy for noise, and that is done in error. DR at high ISOs is not directly relevant to noise except for one thing, a really low DR for an ISO compared to other cameras most likely also means more noise, but there is no direct correlation between DR and noise, and a high DR at a given high ISO is not an indication of low noise; it may be an indication of more headroom; headroom that you would have had anyway had you chosen to "under-expose" at a lower ISO setting instead, with the same Av and Tv values.
If you're shooting a spot-lit stage and plan to leave the darkest areas very dark, "DR" probably has little to do with your concerns, unless there are also very bright highlights outside the normal range that you wish to capture well by using less exposure than normal for an ISO setting. If you're just worried about noise in "normal" tonal ranges, then DR is not a valuable metric, and you should just be concentrating on exposure, by using the largest aperture that gives the look you want, and the slowest shutter speed that you can get away with, and forget about "DR".
In any event, I think that DR is best understood by breaking it up into two parts; headroom, and footroom, both relative to the standard exposure of a grey card for an ISO setting. "Footroom" is how much aesthetically usable range you get below middle grey, and "headroom" is how much extra there is for highlights that can be captured without clipping, and any camera that scores high for DR can be doing that by giving ample headroom and poor footroom, and footroom is the only one that has anything to do with exposure-referred noise.
..... Id like to try working around this with lighting to what I need to achieve when lighting a room with fixed lighting. Perhaps we need to hang a room to be able to achive 1/500 at 500 ISO, keeping 2.8 static? The even wash would require scrims.
