The Exposure Triangle Is Misleading And Unnecessary.

same as it did 20 years ago, it hasnt changed . it just amplifies the pixel signal before the adc.

😁

I think post processing software compounds the confusion.

Some PP software, including the products I use, have a control "Exposure". Of course it can't change the actual exposure, but it's easy to see why folks think it does.

The ISO dial still changes the digital gain of the ADC.

1) What effect does this have on the image
2) What about ISO-less sensors?

p.s.

Yay, now have a personalised avatar. Small minds and all that!

1) To answer this question it is important to know which image in the pipeline we’re talking about?

2) Practically speaking there is more leeway in post. But, yes, what about ISO invariant sensors? What was the intention behind this question as I don’t think this is related to the core of this discussion.

The answer to your questions is in the ISO For Beginners threads in both the Beginners Questions and Beginners Questions Discussion forums.

Or perhaps start your own thread on the topic because your questions have nothing to do with the op.

Currently, ISO setting may control the pixel capacitance, control amplification, control multiplication, force a tag controlling out-of-camera conversion, do nothing except forcing the tag.

Why are you so adamant on being wrong? :))

Iliah,
I was thinking this might deserve a separate thread, but is there a functional significance to the method used? Would the last three "digital" methods be different from the first two?
Thanks
Sherm

Scaling in post has the huge advantage that highlight clipping is under the control of the photographer. IMHO, it should be the default once the ISOless region is reached.

There are lots of ISO implementations, but I am not aware of any where the variable gain function is performed in the ADC.

I think the 20 years ago part is correct; I think we had all the options that Iliah mentioned in one or another camera then. The " it just amplifies the pixel signal before the adc" is incorrect in that it says that only one of the available options was and is employed. The fact that that option is used sometimes doesn't make the statement correct.

The analogue part of the design has its goal, and that goal isn't about ISO. Acceptable signal-to-noise ratio through a wide range of exposures (latitude) is, given the cost, complexity, parts / sections availability.

As Jim explained, leaving ISO "implementation" to digital allows to avoid unnecessary highlight clipping.

One of the promising new design directions that uses a comparator on every pixel allows to avoid variable / programmable gain amplifiers and highlight clipping caused by raising gain there.

One of the reasons of the success of phone cameras is that they progressively less and less rely on the "it's just like film" sort of ideas.

Or any combination of the above...

Tags are better than multiplies, because multiplies that do not give a widened result cause non-linear distortion in the deep shadows. On a PC, we can use high precision for intermediate values.

We've talked about Nikon's baked-in RAW white-balance prescaling before. That should be done with tags too.

My position is that any processing that can be done at least as well in postproduction should be done there, not in the camera. That includes gain in the ISOless regions, lens vignetting correction, lowpass filtering and median filtering, PDAF pixel correction, PDAF striping fixes, etc.

he wanted a simple answer and he got it. same as what does the accelerator pedal actually do on my car. who cares if its by wire or cable 🙄 or even what the fuel/air mixture is. it makes the car go faster and slower, simple.

If you are unconcerned with accuracy, it's easy to come up with simple answers. The truth is that the way it works depends on the camera. I have a GFX 50S. I have a GFX 100S. The ISO settings work differently. Therefore I set the ISO on the two cameras differently.