Exposure understanding and definition

[ZodiacPhoto]

I apologize for bringing this topic again.

I am reading the today's DPR interview with Elliot Shih, Senior Product Manager of Zeiss, about the upcoming ZX1 android-based camera. When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

I think this understanding of ISO as one of the three values affecting exposure, while not strictly correct, is deeply embedded in minds of generations of photographers. Should the photographic community try to change it? Why and how?

It is almost like reminding people that the Earth revolves around the Sun, so they should not say that the Sun is rising or setting...

 

[Tom Axford]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

Just think about it!

The only thing that is "wrong" is the use of the word "exposure", which is being used in one of its various meanings, but not one of the meanings accepted in scientific circles.

In the usual scientific meaning of "exposure", changing the ISO does not change it. However, changing the Exposure slider in Lightroom does not change the exposure (in that sense), either.

 

[Ellis Vener]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

Just think about it!

The only thing that is "wrong" is the use of the word "exposure", which is being used in one of its various meanings, but not one of the meanings accepted in scientific circles.

In the usual scientific meaning of "exposure", changing the ISO does not change it. However, changing the Exposure slider in Lightroom does not change the exposure (in that sense), either.

I agree.

 

[lilBuddha]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

Just think about it!

The only thing that is "wrong" is the use of the word "exposure", which is being used in one of its various meanings, but not one of the meanings accepted in scientific circles.

In the usual scientific meaning of "exposure", changing the ISO does not change it. However, changing the Exposure slider in Lightroom does not change the exposure (in that sense), either.

It is the conflict between technically correct and effective communication.

 

[ZodiacPhoto]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

Just think about it!

The only thing that is "wrong" is the use of the word "exposure", which is being used in one of its various meanings, but not one of the meanings accepted in scientific circles.

In the usual scientific meaning of "exposure", changing the ISO does not change it. However, changing the Exposure slider in Lightroom does not change the exposure (in that sense), either.

True - in a sense that Exposure slider compensates for initial exposure being not exactly what is desired.

It is the conflict between technically correct and effective communication.

 

[iancandler]

If a photographer is manually controlling shutter speed & aperture he should automatically adjust the exposure to his liking using those two controls.

Its only when shooting a subject at the maximum aperture and slowest shutter speed you want to use ie birds (1/1000th sec f2.8) for instance, that you need to ride the ISO to get your desired exposure.

 

[Christof21]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

Just think about it!

I am not sure you really read the posts, it is confirmed now (I refer to another thread)

Just read the title of the thread !!

The OP was not ambiguous at all about what he meant:

"I think this understanding of ISO as one of the three values affecting exposure, while not strictly correct, is deeply embedded in minds of generations of photographers. Should the photographic community try to change it? Why and how?"

 

[Tom Axford]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

Just think about it!

I am not sure you really read the posts, it is confirmed now (I refer to another thread)

Just read the title of the thread !!

The OP was not ambiguous at all about what he meant:

"I think this understanding of ISO as one of the three values affecting exposure, while not strictly correct, is deeply embedded in minds of generations of photographers. Should the photographic community try to change it? Why and how?"

I think it is clear from my post that I agree with the OP, and what I said was aimed more at those who disagreed. Perhaps you misinterpreted my comments as criticism of the OP. I am sorry if it came across that way, but I was making a contribution to the discussion to counter a couple of earlier posts that had said it was rubbish.

 

[Lee Jay]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

No, it's not.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

No, that's false. Changing ISO doesn't change how much light is captured, while changing f-stop or shutter speed does. Since signal-to-noise ratio is controlled by how much light is captured, that's a very significant difference.

 

[Christof21]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

No, it's not.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

No, that's false. Changing ISO doesn't change how much light is captured, while changing f-stop or shutter speed does. Since signal-to-noise ratio is controlled by how much light is captured, that's a very significant difference.

I am not sure this was the topic of the thread, but this part is correct, I agree with Tom.

The OP just wanted to mention the misuse of the term exposure.

 

[Mark_A]

I apologize for bringing this topic again.

I am reading the today's DPR interview with Elliot Shih, Senior Product Manager of Zeiss, about the upcoming ZX1 android-based camera. When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

I think this understanding of ISO as one of the three values affecting exposure, while not strictly correct, is deeply embedded in minds of generations of photographers. Should the photographic community try to change it? Why and how?

It is almost like reminding people that the Earth revolves around the Sun, so they should not say that the Sun is rising or setting...

I don't have a problem with it.

But is this camera going to be manual mode only?

No PAS or scene modes?

And what is this Android business?

Mark_A

 

[Tom Axford]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

No, it's not.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

No, that's false. Changing ISO doesn't change how much light is captured, while changing f-stop or shutter speed does. Since signal-to-noise ratio is controlled by how much light is captured, that's a very significant difference.

My wording was a bit sloppy, instead of "in one of the auto-exposure modes", I should have been more precise and said in auto-ISO mode (with fixed shutter speed and aperture). Not all cameras have this mode, but many do.

Of course, the other auto-exposure modes will try to change the exposure if you change EC, and only change ISO if the shutter speed or aperture has hit the limit of what is available.

 

[sybersitizen]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

I don't care about the never-ending discussions concerning the precise meaning of exposure or why ISO does not affect exposure. That's a rabbit hole with no bottom simply due to confusion of terms. Unlikely to change anytime soon.

What bothers me there is the idea that an 'Exposure Compensation' control is deemed unnecessary in that camera. The purpose of EC is to override the 'normal' meter reading.

For example, what if you like to shoot at a specific aperture while leaving the shutter speed dial in 'A'? That's aperture priority mode, frequently used by many photographers. If you want to reduce the brightness of a scene from the 'normal' meter reading, how do you do that without an EC dial? Setting the ISO to something specific won't help because the camera will still just choose a shutter speed that leaves the overall 'exposure' (brightness) the same.

Apparently, whenever you want to override the 'normal' meter reading with that camera you will have to pick a specific aperture, a specific shutter speed, and a specific ISO.

 

[Lee Jay]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

No, it's not.

If you set the shutter speed and the aperture, then changing the ISO will have exactly the same effect on the resulting image as if you change Exposure Compensation when in one of the auto-exposure modes.

No, that's false. Changing ISO doesn't change how much light is captured, while changing f-stop or shutter speed does. Since signal-to-noise ratio is controlled by how much light is captured, that's a very significant difference.

I am not sure this was the topic of the thread, but this part is correct, I agree with Tom.

Well, this isn't a debate, and the statement is wrong unless you want to change the definition of the word exposure.

The OP just wanted to mention the misuse of the term exposure.

Right...changing ISO does not, by definition, change exposure.

 

[sybersitizen]

What bothers me there is the idea that an 'Exposure Compensation' control is deemed unnecessary in that camera. The purpose of EC is to override the 'normal' meter reading.

For example, what if you like to shoot at a specific aperture while leaving the shutter speed dial in 'A'? That's aperture priority mode, frequently used by many photographers. If you want to reduce the brightness of a scene from the 'normal' meter reading, how do you do that without an EC dial? Setting the ISO to something specific won't help because the camera will still just choose a shutter speed that leaves the overall 'exposure' (brightness) the same.

I guess if you're lucky maybe you can instead spot meter on something that you're willing to designate as the 'normal' brightness value.

 

[FingerPainter]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

If you think about it carefully, this statement is absolutely correct.

...

The only thing that is "wrong" is the use of the word "exposure", which is being used in one of its various meanings, but not one of the meanings accepted in scientific circles.

The two bolded bits seem to contradict each other

 

[jshen808]

I apologize for bringing this topic again.

I am reading the today's DPR interview with Elliot Shih, Senior Product Manager of Zeiss, about the upcoming ZX1 android-based camera. When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

I think this understanding of ISO as one of the three values affecting exposure, while not strictly correct, is deeply embedded in minds of generations of photographers. Should the photographic community try to change it? Why and how?

It is almost like reminding people that the Earth revolves around the Sun, so they should not say that the Sun is rising or setting...

..While I'm not able to comment on the terminologies you are referring to..

..but can mention from experiences, that in more difficult situations in taking pictures, where the camera may not respond the way one wants to, then going manual mode is an option to consider..

..see the below link, took these pictures using manual mode, and manually set the shutter, aperture and iso..

Loading…

www.dpreview.com

..happy shooting my friend..

..Cheers..

 

[Iliah Borg]

Useful definition of exposure is the one that is acceptably universal and helps achieving better quality.

Including ISO speed into definition helps achieving desired lightness, but doesn't help, to say the least, with noise, without demonstrably illogical and wrong crunches like "high ISO noise", something that puts everything onto its head (luminiferous aether).

ISO speed, per standard, shall not be defined for raw. What happens now to the definition of exposure that includes ISO speed? It ceases to exist.

Are we ready to agree that there is no exposure for raw?

 

[Ellis Vener]

Useful definition of exposure is the one that is acceptably universal and helps achieving better quality.

Including ISO speed into definition helps achieving desired lightness, but doesn't help, to say the least, with noise, without demonstrably illogical and wrong crunches like "high ISO noise", something that puts everything onto its head (luminiferous aether).

ISO speed, per standard, shall not be defined for raw. What happens now to the definition of exposure that includes ISO speed? It ceases to exist.

Are we ready to agree that there is no exposure for raw?

 

[ZodiacPhoto]

When talking about the absence of Exposure Compensation dial, the Zeiss manager explained: "If a photographer is manually controlling shutter speed and aperture, then the only way they have of further affecting exposure is ISO. So they can use the ISO dial as exposure compensation, effectively."

I don't care about the never-ending discussions concerning the precise meaning of exposure or why ISO does not affect exposure. That's a rabbit hole with no bottom simply due to confusion of terms. Unlikely to change anytime soon.

What bothers me there is the idea that an 'Exposure Compensation' control is deemed unnecessary in that camera. The purpose of EC is to override the 'normal' meter reading.

For example, what if you like to shoot at a specific aperture while leaving the shutter speed dial in 'A'? That's aperture priority mode, frequently used by many photographers. If you want to reduce the brightness of a scene from the 'normal' meter reading, how do you do that without an EC dial? Setting the ISO to something specific won't help because the camera will still just choose a shutter speed that leaves the overall 'exposure' (brightness) the same.

Apparently, whenever you want to override the 'normal' meter reading with that camera you will have to pick a specific aperture, a specific shutter speed, and a specific ISO.

I don't see a PASM dial on this camera - maybe you can select Aperture or Shutter Priority in the menus. Or this camera will work in Manual mode only then exposure compensation is not needed.