Education continues

If we want to get technical about it, there is no Lambertian reflector that reflects 100% of the light and there is not one that reflects 0% of the light.

I hate one-liners ... grump ...

Yes, while white is not very concerning for what I do, still I add a piece of spectralon; black is more concerning (need it to evaluate flare), and I add a black trap.

Actually, yes, they are to blame in part. My Nikon Z 6 refers to "The ISO (ISO Sensitivity) Button", and goes on to say, "The higher the ISO sensitivity, the less light needed to make an exposure, allowing faster shutter speeds or smaller apertures, but the more likely the image is to be affected by noise..."

The ability of a sensor to resolve light is fixed at design. There is no way to affect its sensitivity to light once it's incorporated into the camera, and all the ISO setting does is to induce some post-capture "gain" to the measurement presented in the raw data. This is really the same situation as we had with film, we'd load a 36-exposure cannister of "sensitivity" into our cameras; if we wanted more sensitivity, we'd chose a different film. Can't do that with our precious digital cameras...

I think the camera manufacturers posit this inaccuracy in order to make their products usable to folks more concerned with making images than with how they're made. What's really sad about this particular abstraction is that it causes people to think that the wrong thing is noising up their images. More ISO tells the metering mode to compel the camera to take in less light, less signal, more variation. More light, more signal, less noise, that's the message that gets lost here...

How many of you remember pushing Kodak Tri-X film (ASA 400) with HC-110 developer replenisher to affect an ASA of 4000? In the '70s, I hung out with a couple of AP stringers who shot Saints football games; they did this so they could set their camera to ASA 4000 and use shutter speeds that froze action in dim lighting. I took that to my high-school football shooting, and reliably got good images for the paper and yearbook.

Those images were grainy, 40-grit sandpaper grainy. But, there was the quarterback, mid-air trying to clear the rushers, mid-throw. So, what grain? But we all knew that it was the dim light that we were dealing with, and coaxing an emulsion to do things it wasn't designed to accommodate...

Never heard of that trick. For N development, I exposed TX at EI 200.

All I can think of is more highlight headroom to work with. Otherwise, every common tone with the same exposure should record better with the ISO cranked, if it also cranks analog gain, except for the Panasonic Z50 and a couple of other weird cameras.

At the high conversion gain settings, there is usually virtually no noise advantage to analog or digital gain in the camera vs in post. And with high-DR scenes, especially those with specularity, highlight clipping can be the long pole in the tent.

I think the designers will assume that the great majority of photos will be saved as JPGs.
Don

I wonder if they're right, especially in the case of the MF cameras.

Makes me glad to own a Sigma SD9! No option but to save as raw ...

Talking about real surfaces I guess ..,. otherwise 100% is possible:

kronometric.org/phot/lighting/lighting%20handbook.pdf page 28

Indeed.

The exposure triangle's role is purely decorative. I consider it a seductive illustration that impairs learning.

We are getting close 0.035%

How does it impairs learning? And learning of what?

It distracts from real knowledge. The exposure triangle is supposed to teach about exposure.