exposure-triangle.com

The ultimate luminosity meter = EVF 😁

It's actually very easy to explain.

It's because it's on the dark side of the moon. Hey, that would be a good album title.

Nope. That is total nonsense 😊

The in camera histogram is at best an approximation of the raw histogram because the in camera histogram is based on the rgb values processed from the raw data.

For a given scene luminance the in camera histogram will vary depending on variables like the metering mode, the WB setting, the camera's 'picture style' settings set by the user etc.

Simple. Because photography is all about ISO. That's why cameras have an ISO button or a dial, and lots of other ISO features. Photographers should always set their ISO first and let the camera worry about everything else automatically.

Why what?

Higher ISO is but a cheat, when the photographer fails to provide adequate scene illumination.
No photo without sufficient light, so that's what photographers should worry about first.

To read the above reinforces my opinion that the number found on film canisters should never have found it's way into the world of digital camera adjustment.

Setting a higher ISO number is telling the metering system to give less exposure. It's the same as Exposure Compensation but also tells the JPG engine to try to reduce the damage.
It gives less camera shake but more noise.

Don

You're probably right, Ted.
Don

I didn't register, so I didn't get access to his "cheat sheets" but he actually isn't promoting the exposure triangle on his teaser homepage. In fact, he goes to some pains to explain that the exposure triangle is "wrong". It appears he's using "exposure triangle" as a kind of internet search honeypot to attract misinformed/novice photographers to his training stuff.

This is a couple of quotes from another tread 😁

I'm wondering how Pete knew what the scene brightness was ...

I determined it using the exposure triangle.

Gold 😁

On the other hand, this makes more sense:
exposure-triangle.com/#exposure_in_photography
(Scroll down to “What are the components of exposure” - brightness of the scene, aperture, and shutter speed)

how do you measure the brightness of a scene 😊 and what components/functions in camera do you need to display them 😊

without gain you have no image. how many OP amps are before ADC 😊 in fact the photo diode voltage/charge isnt the voltage thats even sampled.

An operational amplifier is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op amp produces an output potential that is typically 100,000 times larger than the potential difference between its input terminals.

ISO IS THE GAIN
The truth is, it’s much easier than that. ISO is the gain that is applied to the amount of light your camera sensor has “recorded”. And being exactly that, the gain, it has nothing to do with exposure. It is applied by the cameras processor long after the shutter has closed.
Nevertheless, the gain has an influence on image brightness

Summary: higher gain (ISO) – brighter image

Lightness.

Beginners (and the majority of viewers) care more about the final image, not so much about raw files.

At base iso many cameras apply no gain and still output an image.

In the PAS modes raising iso maintains the same image lightness because either shutter speed or aperture are adjusted to reduce the exposure* by the same amount thus maintaining the same image lightness.

* exposure. - amount of light that struck the sensor per unit area while the shutter was open.