"Crop-ability" of images?

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bobn2
bobn2 Forum Pro • Posts: 69,811
Re: "Crop-ability" of images?
1

Donald B wrote:

Wu Jiaqiu wrote:

Donald B wrote:

Wu Jiaqiu wrote:

john isaacs wrote:

Wu Jiaqiu wrote:

Donald B wrote:

bobn2 wrote:

Donald B wrote:

bobn2 wrote:

Muster Mark wrote:

bobn2 wrote:

dperez wrote:

More photographers who’s judgement I respect are talking about moving to Olympus. A question came up the other day and I’m trying to figure out the answer.

Nikon D850, 600mm f/4 versus M1X, 300mm f/4.

As I understand it - the lenses are the same equivalent - 600mm. The Nikon shoots at f/8 and ISO 3200 and 1/500. The M1X shoots at f/4 so the DOF is the same, and ISO 800 and 1/500, so the exposure is the same, right?

Wrong! Somewhere along the way you've picked up a wrong idea of what 'exposure' means. It does not mean how light or dark the image is. It means what is the light energy density at the sensor. It is determined by shutter speed, f-number and scene luminance. In your example, since the shutter speed and scene luminance are the same, but the f-number is two stops higher on the Nikon, it will have two stops less exposure. But it will make up for it by having four times the sensor area.

I think he was saying he puts the Nikon at f8 and gets the same results as the Oly at F4. This is correct. He has the Nikon shooting at ISO 3200 and the oly at ISO 800. I don't think your criticism of his understanding is warranted.

I didn't criticise his understanding except for the meaning of 'exposure', which he got wrong. This misunderstanding is unfortunately common. As you say, if he was saying that he gets the same 'results' or lightness, then yes, he's right.

I like this quote "The “Exposure Triangle,” as it is often referred to, is a handy way of interpreting the major components involved in the process of capturing an image.

Yes, I think that the 'triangle' is responsible for people thinking wrongly that the components of exposure are aperture, shutter and ISO.

well think of it like this , to expose a viewable image on the camera rear lcd or evf . the camera requires the correct aperture ,shutter speed and iso now try to argue against that

When invented by Bryan Peterson it was the 'Photographic Triangle'. Whatever the name, it's useless.

iso you say....the rabbit hole beckons

Exposure triangle:

https://www.cambridgeincolour.com/tutorials/camera-exposure.htm

Exposure settings:

https://www.adobe.com/creativecloud/photography/hub/guides/camera-exposure-camera-settings.html

Because when people think of "exposure", they think of the image.

ISO does not change the sensor's sensitivity to light though as per the adobe article, it's wrong

a light meter requires 3 inputs from the user for it to work.

There are lots of kinds of light meter, but I suspect you're talking about one particular type, an 'exposure meter'. Even then, it's not the case. Over the history of photography, exposure meters have come in many shapes and forms. To calculate exposure you need the scene luminance and the EV (combination of shutter speed and f-number). Some meters give you a direct reading of scene luminance and then provide tables to calculate exposure, given different EV values. However, mostly photographers have not been so interested in what is the exposure, they want to match the target exposure specified by the ISO (or before that the ASA or DIN). For hand held meters, you's generally set the target exposure, by means of setting the ISO, and the meter would tell you the EV setting to use, or it would separate it out into f-number and shutter speed. You set one, and it tells you the other. For coupled meters the norm was to display the difference from the target exposure with the selected f-number and shutter speed.

Mostly people who make this mistake of what exposure is have never used a separate exposure meter or if they have, haven't understood what they are doing with it.

Don

does that change your sensor's sensitivity to light?

A gain control controls the sensors sensitivity’s, which I presume is the iso control can’t image its further down the track. Same as gain control on a radio receiver.

Din

I thought my typing was bad, but I usually get my own name right.

Anyhow, the gain control on a radio receiver only affects its sensitivity for an AM radio using a diode detector. The amplitude of the carrier needs to be larger than the diode's forward voltage for the signal to be detected, this 'sensitivity', in the sense of what is the smallest signal that can be detected, can be increased by putting gain in front of the detector stage. In a camera, the limit to the smallest signal that can be detected is generally the ADC noise, so putting gain before the ADC can increase sensitivity in that regard. It doesn't increase the 'sensitivity to light' of the sensor, it just makes the 'detector' (i.e. the ADC) better at decoding small signals. That gain control is usually linked to the ISO control over at least some of its range, but the 'gain' is not 'ISO'. 'ISO' is what ISO says it is in its standard, and it doesn't say that it is 'gain'.

Bib

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(unknown member) Forum Pro • Posts: 19,317
Re: "Crop-ability" of images?
1

Iliah Borg wrote:

Donald B wrote:

A gain control controls the sensors sensitivity

No, it doesn't. Look at any sensor data sheet, sensor sensitivity / responsivity is given irrespective to gain.

So what controls an over saturated signal from the sensor ? to the next stage. just asking as im not  familar with sensor circuits .

Don

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Wu Jiaqiu
Wu Jiaqiu Forum Pro • Posts: 27,532
Re: "Crop-ability" of images?
1

Donald B wrote:

Wu Jiaqiu wrote:

Donald B wrote:

Wu Jiaqiu wrote:

Donald B wrote:

Wu Jiaqiu wrote:

john isaacs wrote:

Wu Jiaqiu wrote:

Donald B wrote:

bobn2 wrote:

Donald B wrote:

bobn2 wrote:

Muster Mark wrote:

bobn2 wrote:

dperez wrote:

More photographers who’s judgement I respect are talking about moving to Olympus. A question came up the other day and I’m trying to figure out the answer.

Nikon D850, 600mm f/4 versus M1X, 300mm f/4.

As I understand it - the lenses are the same equivalent - 600mm. The Nikon shoots at f/8 and ISO 3200 and 1/500. The M1X shoots at f/4 so the DOF is the same, and ISO 800 and 1/500, so the exposure is the same, right?

Wrong! Somewhere along the way you've picked up a wrong idea of what 'exposure' means. It does not mean how light or dark the image is. It means what is the light energy density at the sensor. It is determined by shutter speed, f-number and scene luminance. In your example, since the shutter speed and scene luminance are the same, but the f-number is two stops higher on the Nikon, it will have two stops less exposure. But it will make up for it by having four times the sensor area.

I think he was saying he puts the Nikon at f8 and gets the same results as the Oly at F4. This is correct. He has the Nikon shooting at ISO 3200 and the oly at ISO 800. I don't think your criticism of his understanding is warranted.

I didn't criticise his understanding except for the meaning of 'exposure', which he got wrong. This misunderstanding is unfortunately common. As you say, if he was saying that he gets the same 'results' or lightness, then yes, he's right.

I like this quote "The “Exposure Triangle,” as it is often referred to, is a handy way of interpreting the major components involved in the process of capturing an image.

Yes, I think that the 'triangle' is responsible for people thinking wrongly that the components of exposure are aperture, shutter and ISO.

well think of it like this , to expose a viewable image on the camera rear lcd or evf . the camera requires the correct aperture ,shutter speed and iso now try to argue against that

When invented by Bryan Peterson it was the 'Photographic Triangle'. Whatever the name, it's useless.

iso you say....the rabbit hole beckons

Exposure triangle:

https://www.cambridgeincolour.com/tutorials/camera-exposure.htm

Exposure settings:

https://www.adobe.com/creativecloud/photography/hub/guides/camera-exposure-camera-settings.html

Because when people think of "exposure", they think of the image.

ISO does not change the sensor's sensitivity to light though as per the adobe article, it's wrong

a light meter requires 3 inputs from the user for it to work.

Don

does that change your sensor's sensitivity to light?

A gain control controls the sensors sensitivity’s, which I presume is the iso control can’t image its further down the track. Same as gain control on a radio receiver.

Din

the volume control when i listen to the radio on my laptop works very differently to the volume control on an old valve radio

No its the same , the potentiometer is just before the af preamp stage. a gain control is between the antenna and the rf stage basically. been a while i hope thats not to simplified 40 years since i passed my ham .

anyway im backing nikon usa site

https://www.nikonusa.com/en/learn-and-explore/a/products-and-innovation/iso-control.html

that ISO setting still isn't changing the sensitivity of the sensor

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bobn2
bobn2 Forum Pro • Posts: 69,811
Re: Why?
1

Donald B wrote:

OK then. ISO 400, f/8, 1/2000. What's the exposure?

1/2000sec

Aha, so exposure means shutter speed. How did I ever miss that?

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(unknown member) Forum Pro • Posts: 19,317
Re: "Crop-ability" of images?

bobn2 wrote:

Donald B wrote:

Wu Jiaqiu wrote:

Donald B wrote:

Wu Jiaqiu wrote:

john isaacs wrote:

Wu Jiaqiu wrote:

Donald B wrote:

bobn2 wrote:

Donald B wrote:

bobn2 wrote:

Muster Mark wrote:

bobn2 wrote:

dperez wrote:

More photographers who’s judgement I respect are talking about moving to Olympus. A question came up the other day and I’m trying to figure out the answer.

Nikon D850, 600mm f/4 versus M1X, 300mm f/4.

As I understand it - the lenses are the same equivalent - 600mm. The Nikon shoots at f/8 and ISO 3200 and 1/500. The M1X shoots at f/4 so the DOF is the same, and ISO 800 and 1/500, so the exposure is the same, right?

Wrong! Somewhere along the way you've picked up a wrong idea of what 'exposure' means. It does not mean how light or dark the image is. It means what is the light energy density at the sensor. It is determined by shutter speed, f-number and scene luminance. In your example, since the shutter speed and scene luminance are the same, but the f-number is two stops higher on the Nikon, it will have two stops less exposure. But it will make up for it by having four times the sensor area.

I think he was saying he puts the Nikon at f8 and gets the same results as the Oly at F4. This is correct. He has the Nikon shooting at ISO 3200 and the oly at ISO 800. I don't think your criticism of his understanding is warranted.

I didn't criticise his understanding except for the meaning of 'exposure', which he got wrong. This misunderstanding is unfortunately common. As you say, if he was saying that he gets the same 'results' or lightness, then yes, he's right.

I like this quote "The “Exposure Triangle,” as it is often referred to, is a handy way of interpreting the major components involved in the process of capturing an image.

Yes, I think that the 'triangle' is responsible for people thinking wrongly that the components of exposure are aperture, shutter and ISO.

well think of it like this , to expose a viewable image on the camera rear lcd or evf . the camera requires the correct aperture ,shutter speed and iso now try to argue against that

When invented by Bryan Peterson it was the 'Photographic Triangle'. Whatever the name, it's useless.

iso you say....the rabbit hole beckons

Exposure triangle:

https://www.cambridgeincolour.com/tutorials/camera-exposure.htm

Exposure settings:

https://www.adobe.com/creativecloud/photography/hub/guides/camera-exposure-camera-settings.html

Because when people think of "exposure", they think of the image.

ISO does not change the sensor's sensitivity to light though as per the adobe article, it's wrong

a light meter requires 3 inputs from the user for it to work.

There are lots of kinds of light meter, but I suspect you're talking about one particular type, an 'exposure meter'. Even then, it's not the case. Over the history of photography, exposure meters have come in many shapes and forms. To calculate exposure you need the scene luminance and the EV (combination of shutter speed and f-number). Some meters give you a direct reading of scene luminance and then provide tables to calculate exposure, given different EV values. However, mostly photographers have not been so interested in what is the exposure, they want to match the target exposure specified by the ISO (or before that the ASA or DIN). For hand held meters, you's generally set the target exposure, by means of setting the ISO, and the meter would tell you the EV setting to use, or it would separate it out into f-number and shutter speed. You set one, and it tells you the other. For coupled meters the norm was to display the difference from the target exposure with the selected f-number and shutter speed.

Mostly people who make this mistake of what exposure is have never used a separate exposure meter or if they have, haven't understood what they are doing with it.

Don

does that change your sensor's sensitivity to light?

A gain control controls the sensors sensitivity’s, which I presume is the iso control can’t image its further down the track. Same as gain control on a radio receiver.

Din

I thought my typing was bad, but I usually get my own name right.

Anyhow, the gain control on a radio receiver only affects its sensitivity for an AM radio using a diode detector. The amplitude of the carrier needs to be larger than the diode's forward voltage for the signal to be detected, this 'sensitivity', in the sense of what is the smallest signal that can be detected, can be increased by putting gain in front of the detector stage.

But what if you added a multi element yagi with a 6db gain, if a strong station was close the gain control would then need to decrease the signal, wouldnt that be the same as a bright lens and sunny day ?

In a camera, the limit to the smallest signal that can be detected is generally the ADC noise, so putting gain before the ADC can increase sensitivity in that regard. It doesn't increase the 'sensitivity to light' of the sensor, it just makes the 'detector' (i.e. the ADC) better at decoding small signals. That gain control is usually linked to the ISO control over at least some of its range, but the 'gain' is not 'ISO'. 'ISO' is what ISO says it is in its standard, and it doesn't say that it is 'gain'.

Bib

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(unknown member) Forum Pro • Posts: 19,317
Re: Hah?

Iliah Borg wrote:

Donald B wrote:

ISO 400, f/8, 1/2000. What's the exposure?

1/2000sec

Photographic exposure is measured in lux seconds, how do you convert 1/2000 to lux seconds?

Now your getting to technical

Don

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Iliah Borg Forum Pro • Posts: 28,756
Re: "Crop-ability" of images?
1

Donald B wrote:

Iliah Borg wrote:

Donald B wrote:

A gain control controls the sensors sensitivity

No, it doesn't. Look at any sensor data sheet, sensor sensitivity / responsivity is given irrespective to gain.

So what controls an over saturated signal from the sensor ? to the next stage. just asking as im not familar with sensor circuits .

Don

Not sure what you are asking. What is over-saturated signal and what are the conditions causing such signal to emerge?

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Re: Why?

bobn2 wrote:

Donald B wrote:

OK then. ISO 400, f/8, 1/2000. What's the exposure?

1/2000sec

Aha, so exposure means shutter speed. How did I ever miss that?

I went even simpler and thought of sun exposure to your skin i didnt add sunscreen as aperture

Don

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Iliah Borg Forum Pro • Posts: 28,756
Re: Hah?
5

Donald B wrote:

Iliah Borg wrote:

Donald B wrote:

ISO 400, f/8, 1/2000. What's the exposure?

1/2000sec

Photographic exposure is measured in lux seconds, how do you convert 1/2000 to lux seconds?

Now your getting to technical

As opposite to wrong?

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(unknown member) Forum Pro • Posts: 19,317
Re: "Crop-ability" of images?

Iliah Borg wrote:

Donald B wrote:

Iliah Borg wrote:

Donald B wrote:

A gain control controls the sensors sensitivity

No, it doesn't. Look at any sensor data sheet, sensor sensitivity / responsivity is given irrespective to gain.

So what controls an over saturated signal from the sensor ? to the next stage. just asking as im not familar with sensor circuits .

Don

Not sure what you are asking. What is over-saturated signal and what are the conditions causing such signal to emerge?

signal distortion , eg screaming into a microphone ,the pre amp is over saturated with  voltage, so a pot pulls it back. sunny day f 1.2 shutter 1/200 sec

Don

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john isaacs Veteran Member • Posts: 6,113
Exposure vs Exposure
1

bobn2 wrote:

john isaacs wrote:

Well, I put up some links, and I'm perfectly happy with them.

For myself, I suggest that ISO and Kodak trumps 'Cambridge in Colour' and Adobe. Another bit from the Kodak Sensitometry workbook, in the glossary they give, for people that are unfamiliar with the terms:

Okay, here's the thing.  We seem to be talking about two different things that are defined by the same word.  For you, Exposure is a quantitative value that is the amount light that reaches the sensor when capturing an image.  For me, Exposure is the (v.) act of capturing and image, or (n.) the actual image.

When I talk about an exposure, I am talking about the image, and when I talk about exposure settings, I am talking about the camera settings that were used to capture the image.  And those are shutter speed, aperture, ISO, and Exposure Compensation if non-zero.

I have no idea under what circumstances you would use the term Exposure, or how you would use it without mentioning ISO.  But you can explain that for yourself.

I've provided links that define and illustrate the use of the term Exposure as I and others mean it.  When I use the term, it is always clear what is meant.

The problem, as I see it, is that you are not satisfied with this, and want to correct people in the use of the term Exposure.  But you don't provide a satisfactory substitution, you just say "that's wrong".  Well, that is not useful, and in fact it is not necessary, either.  You are not the "word police".  If you have something constructive to say, rather than to simply correct the use of this word, then say it.  Nit-picking over the use of Exposure is neither helpful, nor civil.

Feel free to explain how your use of the term Exposure is useful.  Stop trying to correct other peoples use of the term; there are enough definitions out there to prove that their use is valid.  And if you think there is something helpful to be said, then go right ahead.

For me; I'm sticking with the use of Exposure that communicates what I mean to say.  Works for me.

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(unknown member) Forum Pro • Posts: 19,317
Re: Exposure vs Exposure

john isaacs wrote:

bobn2 wrote:

john isaacs wrote:

Well, I put up some links, and I'm perfectly happy with them.

For myself, I suggest that ISO and Kodak trumps 'Cambridge in Colour' and Adobe. Another bit from the Kodak Sensitometry workbook, in the glossary they give, for people that are unfamiliar with the terms:

Okay, here's the thing. We seem to be talking about two different things that are defined by the same word. For you, Exposure is a quantitative value that is the amount light that reaches the sensor when capturing an image. For me, Exposure is the (v.) act of capturing and image, or (n.) the actual image.

When I talk about an exposure, I am talking about the image, and when I talk about exposure settings, I am talking about the camera settings that were used to capture the image. And those are shutter speed, aperture, ISO, and Exposure Compensation if non-zero.

I have no idea under what circumstances you would use the term Exposure, or how you would use it without mentioning ISO. But you can explain that for yourself.

I've provided links that define and illustrate the use of the term Exposure as I and others mean it. When I use the term, it is always clear what is meant.

The problem, as I see it, is that you are not satisfied with this, and want to correct people in the use of the term Exposure. But you don't provide a satisfactory substitution, you just say "that's wrong". Well, that is not useful, and in fact it is not necessary, either. You are not the "word police". If you have something constructive to say, rather than to simply correct the use of this word, then say it. Nit-picking over the use of Exposure is neither helpful, nor civil.

Feel free to explain how your use of the term Exposure is useful. Stop trying to correct other peoples use of the term; there are enough definitions out there to prove that their use is valid. And if you think there is something helpful to be said, then go right ahead.

For me; I'm sticking with the use of Exposure that communicates what I mean to say. Works for me.

me to , doesnt make sense or for any practical purpose without iso. other wise why does dpr exif data include iso if it didnt matter.

Don

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Tony Rogers Senior Member • Posts: 2,054
Re: "Crop-ability" of images?

dperez wrote:

I was ready to put down the money for an A1 and several lenses as a replacement for my D850 and D500 - which is the camera I shoot BIF with. And instead of the A7R IV and A9 II. Then I found out the A1 can't do focus stacking. It appears that none of the current Sony's do focus stacking. AND it doesn't have a fully articulating LCD, just the old-style tilting one like my Nikons.

Yes, I wasn't trying to sell you an A1. Sony has far fewer in-camera computational photography features, particularly when compared to Olympus who are probably the market leaders with Hand-Held hi-res, Live ND, Live Composite, Focus Stacking etc.

Probably 20% of my images with the D850 are flowers and other closeup things, and both landscapes, close-ups and macros are routinely focus stacked... Not having that capability meant keeping my current equipment and having 2 drastically different systems... Bad idea.

From the Sony forums it APPEARS the belief is that it's just a firmware upgrade, but it doesn't seem to be on Sony's radar as something to be done any time soon.

I wouldn't hold my breath. Sony's record of introducing features with firmware updates is inconsistent. It's been great in term of AF for certain cameras and other, relatively simple features remain missing.

So, I'm still looking at options...

My main point was, don't assume all cameras will C-AF as well as a D850. And mirrorless cameras in general have different issues to overcome to do with using the sensor for PDAF that dslr users might find a bit jarring to adjust to. (Basically, if the subject - let's say a bird - is so far out of focus that you can't see it in EVF, it means the mirrorless camera isn't getting reliable pdaf information on the bird. That means it will either focus on something that is clear in the viewfinder (say the background) or it will guess which way to move the focus to try to find something, by which time the bird is gone! My understanding is that dslrs are less prone to this failure due to the way the separate pdaf sensor and associated optics work.)

I'm just suggesting you try before you buy to make sure a new camera suits you from this autofocus perspective.

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bobn2
bobn2 Forum Pro • Posts: 69,811
Re: Exposure vs Exposure
2

john isaacs wrote:

bobn2 wrote:

john isaacs wrote:

Well, I put up some links, and I'm perfectly happy with them.

For myself, I suggest that ISO and Kodak trumps 'Cambridge in Colour' and Adobe. Another bit from the Kodak Sensitometry workbook, in the glossary they give, for people that are unfamiliar with the terms:

Okay, here's the thing. We seem to be talking about two different things that are defined by the same word.

Yes, clearly.

For you, Exposure is a quantitative value that is the amount light that reaches the sensor when capturing an image.

Because that is how exposure is defined in photography.

For me, Exposure is the (v.) act of capturing

Exposure is always a noun. The verb is 'expose'. 'The act of capturing' is a thing, therefore a word to describe it is a noun.

and image, or (n.) the actual image.

'Image' is a better word, that doesn't risk misinterpretation in the same way that you do if you misuse a photographic jargon word.

When I talk about an exposure, I am talking about the image, and when I talk about exposure settings, I am talking about the camera settings that were used to capture the image. And those are shutter speed, aperture, ISO, and Exposure Compensation if non-zero.

Plus a whole load of other things that affect 'the image'. Focus, focal length. Processing settings. Colour temperature. You are separating out just the things that determine lightness, with your workflow. The reason for that is that you are confusing lightness and exposure. It's a very common confusion, and one that leads down a rabbit-hole of fallacies and confusions when it comes to understanding what the technical side of photography is all about.

I have no idea under what circumstances you would use the term Exposure, or how you would use it without mentioning ISO. But you can explain that for yourself.

You'd use the term exposure when you mean exposure, as photographers have been doing for a very long time. But you probably have no idea how you'd use the term because you don't know what either exposure or ISO is.

I've provided links that define and illustrate the use of the term Exposure as I and others mean it. When I use the term, it is always clear what is meant.

Absolutely not. It doesn't seem clear even to yourself, given that you've made quite a number of contradictory statements about what you mean

The problem, as I see it, is that you are not satisfied with this, and want to correct people in the use of the term Exposure. But you don't provide a satisfactory substitution, you just say "that's wrong". Well, that is not useful, and in fact it is not necessary, either. You are not the "word police". If you have something constructive to say, rather than to simply correct the use of this word, then say it. Nit-picking over the use of Exposure is neither helpful, nor civil.

Photography, like most technical exploits, depends on a specialised vocabulary. One of the most basic concepts in photography is the light energy density at the focal plane, so it is given a word to signify just that concept. The word is 'exposure'. From that one concept springs related concepts of speed of photosensitive surfaces and exposure indexes. Once people start misusing the specialised vocabulary and assigning different meanings to the core concepts, then the vocabulary becomes seriously degraded.

Feel free to explain how your use of the term Exposure is useful.

I have done so a number of times already.

Stop trying to correct other peoples use of the term; there are enough definitions out there to prove that their use is valid.

An invalid definition doesn't make usage following it 'valid', however commonplace the invalid definition.

And if you think there is something helpful to be said, then go right ahead.

The problem is with technical vocabularies is that people that don't understand them adopt them to try and fit in with some kind of club, as an indicator of their presumed proficiency. Unfortunately what they are doing is the opposite. Show a picture that is too dark to a non photographer and they will likely say 'it's too dark', and will be right. Show it to this kind of photographer and they will say 'it's underexposed', and they might well be wrong, because a small exposure makes a picture too dark only under some specific circumstances. So, whereas the lay person will never be wrong, the photographer that mangles the technical jargon of the subject will often get it wrong and show themselves up as someone ignorant of the basics in the process.

For me; I'm sticking with the use of Exposure that communicates what I mean to say. Works for me.

What it communicates is that you don't know what exposure is. If you don't know what exposure is that suggests that you don't know very much about photography. If that's what works for you, then fine. But I'll still be pointing out the error, in case other poor souls pick up the same wrong definition from you and unwittingly go around letting people know that they don't know anything about photography. Someone did that to you at some stage.

So, I'm afraid that I'm not going to accept your order to stop correcting people misusing the basic vocabulary of photography. A small correction helps understanding and shouldn't cause offence. It's only on those that insist that their misinformation should be the new truth that will draw what should be very simple into this kind of lengthy dispute.

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bobn2 Forum Pro • Posts: 69,811
Re: Exposure vs Exposure
1

Donald B wrote:

me to , doesnt make sense or for any practical purpose without iso. other wise why does dpr exif data include iso if it didnt matter.

Don

That's a non-sequitur, Don. No-one in this discussion has said that ISO 'doesn't matter'. What they have said is that ISO is a not a component of exposure. On the logic of your argument the available sizes, when it was captured, when it was uploaded and the focal length are also parts of exposure. DPR includes EXIF data that it thinks might be of interest, and none of that is exposure. Some of it is the value of controls that can affect exposure.

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(unknown member) Forum Pro • Posts: 19,317
Re: Exposure vs Exposure

bobn2 wrote:

john isaacs wrote:

bobn2 wrote:

john isaacs wrote:

Well, I put up some links, and I'm perfectly happy with them.

For myself, I suggest that ISO and Kodak trumps 'Cambridge in Colour' and Adobe. Another bit from the Kodak Sensitometry workbook, in the glossary they give, for people that are unfamiliar with the terms:

Okay, here's the thing. We seem to be talking about two different things that are defined by the same word.

Yes, clearly.

For you, Exposure is a quantitative value that is the amount light that reaches the sensor when capturing an image.

Because that is how exposure is defined in photography.

For me, Exposure is the (v.) act of capturing

Exposure is always a noun. The verb is 'expose'. 'The act of capturing' is a thing, therefore a word to describe it is a noun.

and image, or (n.) the actual image.

'Image' is a better word, that doesn't risk misinterpretation in the same way that you do if you misuse a photographic jargon word.

When I talk about an exposure, I am talking about the image, and when I talk about exposure settings, I am talking about the camera settings that were used to capture the image. And those are shutter speed, aperture, ISO, and Exposure Compensation if non-zero.

Plus a whole load of other things that affect 'the image'. Focus, focal length. Processing settings. Colour temperature. You are separating out just the things that determine lightness, with your workflow. The reason for that is that you are confusing lightness and exposure. It's a very common confusion, and one that leads down a rabbit-hole of fallacies and confusions when it comes to understanding what the technical side of photography is all about.

I have no idea under what circumstances you would use the term Exposure, or how you would use it without mentioning ISO. But you can explain that for yourself.

You'd use the term exposure when you mean exposure, as photographers have been doing for a very long time. But you probably have no idea how you'd use the term because you don't know what either exposure or ISO is.

I've provided links that define and illustrate the use of the term Exposure as I and others mean it. When I use the term, it is always clear what is meant.

Absolutely not. It doesn't seem clear even to yourself, given that you've made quite a number of contradictory statements about what you mean

The problem, as I see it, is that you are not satisfied with this, and want to correct people in the use of the term Exposure. But you don't provide a satisfactory substitution, you just say "that's wrong". Well, that is not useful, and in fact it is not necessary, either. You are not the "word police". If you have something constructive to say, rather than to simply correct the use of this word, then say it. Nit-picking over the use of Exposure is neither helpful, nor civil.

Photography, like most technical exploits, depends on a specialised vocabulary. One of the most basic concepts in photography is the light energy density at the focal plane, so it is given a word to signify just that concept. The word is 'exposure'. From that one concept springs related concepts of speed of photosensitive surfaces and exposure indexes. Once people start misusing the specialised vocabulary and assigning different meanings to the core concepts, then the vocabulary becomes seriously degraded.

Feel free to explain how your use of the term Exposure is useful.

I have done so a number of times already.

Stop trying to correct other peoples use of the term; there are enough definitions out there to prove that their use is valid.

An invalid definition doesn't make usage following it 'valid', however commonplace the invalid definition.

And if you think there is something helpful to be said, then go right ahead.

The problem is with technical vocabularies is that people that don't understand them adopt them to try and fit in with some kind of club, as an indicator of their presumed proficiency. Unfortunately what they are doing is the opposite. Show a picture that is too dark to a non photographer and they will likely say 'it's too dark', and will be right. Show it to this kind of photographer and they will say 'it's underexposed', and they might well be wrong, because a small exposure makes a picture too dark only under some specific circumstances. So, whereas the lay person will never be wrong, the photographer that mangles the technical jargon of the subject will often get it wrong and show themselves up as someone ignorant of the basics in the process.

For me; I'm sticking with the use of Exposure that communicates what I mean to say. Works for me.

What it communicates is that you don't know what exposure is. If you don't know what exposure is that suggests that you don't know very much about photography. If that's what works for you, then fine. But I'll still be pointing out the error, in case other poor souls pick up the same wrong definition from you and unwittingly go around letting people know that they don't know anything about photography. Someone did that to you at some stage.

So, I'm afraid that I'm not going to accept your order to stop correcting people misusing the basic vocabulary of photography. A small correction helps understanding and shouldn't cause offence. It's only on those that insist that their misinformation should be the new truth that will draw what should be very simple into this kind of lengthy dispute.

Maybe this guy and everyone else on the planet doesnt understand either.

https://www.slrlounge.com/photography-essentials-the-sunny-16-rule/

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john isaacs Veteran Member • Posts: 6,113
Re: Exposure vs Exposure

Donald B wrote:

bobn2 wrote:

john isaacs wrote:

bobn2 wrote:

john isaacs wrote:

Well, I put up some links, and I'm perfectly happy with them.

For myself, I suggest that ISO and Kodak trumps 'Cambridge in Colour' and Adobe. Another bit from the Kodak Sensitometry workbook, in the glossary they give, for people that are unfamiliar with the terms:

Okay, here's the thing. We seem to be talking about two different things that are defined by the same word.

Yes, clearly.

For you, Exposure is a quantitative value that is the amount light that reaches the sensor when capturing an image.

Because that is how exposure is defined in photography.

For me, Exposure is the (v.) act of capturing

Exposure is always a noun. The verb is 'expose'. 'The act of capturing' is a thing, therefore a word to describe it is a noun.

and image, or (n.) the actual image.

'Image' is a better word, that doesn't risk misinterpretation in the same way that you do if you misuse a photographic jargon word.

When I talk about an exposure, I am talking about the image, and when I talk about exposure settings, I am talking about the camera settings that were used to capture the image. And those are shutter speed, aperture, ISO, and Exposure Compensation if non-zero.

Plus a whole load of other things that affect 'the image'. Focus, focal length. Processing settings. Colour temperature. You are separating out just the things that determine lightness, with your workflow. The reason for that is that you are confusing lightness and exposure. It's a very common confusion, and one that leads down a rabbit-hole of fallacies and confusions when it comes to understanding what the technical side of photography is all about.

I have no idea under what circumstances you would use the term Exposure, or how you would use it without mentioning ISO. But you can explain that for yourself.

You'd use the term exposure when you mean exposure, as photographers have been doing for a very long time. But you probably have no idea how you'd use the term because you don't know what either exposure or ISO is.

I've provided links that define and illustrate the use of the term Exposure as I and others mean it. When I use the term, it is always clear what is meant.

Absolutely not. It doesn't seem clear even to yourself, given that you've made quite a number of contradictory statements about what you mean

The problem, as I see it, is that you are not satisfied with this, and want to correct people in the use of the term Exposure. But you don't provide a satisfactory substitution, you just say "that's wrong". Well, that is not useful, and in fact it is not necessary, either. You are not the "word police". If you have something constructive to say, rather than to simply correct the use of this word, then say it. Nit-picking over the use of Exposure is neither helpful, nor civil.

Photography, like most technical exploits, depends on a specialised vocabulary. One of the most basic concepts in photography is the light energy density at the focal plane, so it is given a word to signify just that concept. The word is 'exposure'. From that one concept springs related concepts of speed of photosensitive surfaces and exposure indexes. Once people start misusing the specialised vocabulary and assigning different meanings to the core concepts, then the vocabulary becomes seriously degraded.

Feel free to explain how your use of the term Exposure is useful.

I have done so a number of times already.

Stop trying to correct other peoples use of the term; there are enough definitions out there to prove that their use is valid.

An invalid definition doesn't make usage following it 'valid', however commonplace the invalid definition.

And if you think there is something helpful to be said, then go right ahead.

The problem is with technical vocabularies is that people that don't understand them adopt them to try and fit in with some kind of club, as an indicator of their presumed proficiency. Unfortunately what they are doing is the opposite. Show a picture that is too dark to a non photographer and they will likely say 'it's too dark', and will be right. Show it to this kind of photographer and they will say 'it's underexposed', and they might well be wrong, because a small exposure makes a picture too dark only under some specific circumstances. So, whereas the lay person will never be wrong, the photographer that mangles the technical jargon of the subject will often get it wrong and show themselves up as someone ignorant of the basics in the process.

For me; I'm sticking with the use of Exposure that communicates what I mean to say. Works for me.

What it communicates is that you don't know what exposure is. If you don't know what exposure is that suggests that you don't know very much about photography. If that's what works for you, then fine. But I'll still be pointing out the error, in case other poor souls pick up the same wrong definition from you and unwittingly go around letting people know that they don't know anything about photography. Someone did that to you at some stage.

So, I'm afraid that I'm not going to accept your order to stop correcting people misusing the basic vocabulary of photography. A small correction helps understanding and shouldn't cause offence. It's only on those that insist that their misinformation should be the new truth that will draw what should be very simple into this kind of lengthy dispute.

Maybe this guy and everyone else on the planet doesnt understand either.

https://www.slrlounge.com/photography-essentials-the-sunny-16-rule/

No, he doesn’t understand. He can talk about Lux all he wants. No one cares. It’s the image that matters.

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Iliah Borg Forum Pro • Posts: 28,756
Re: "Crop-ability" of images?

Donald B wrote:

Iliah Borg wrote:

Donald B wrote:

Iliah Borg wrote:

Donald B wrote:

A gain control controls the sensors sensitivity

No, it doesn't. Look at any sensor data sheet, sensor sensitivity / responsivity is given irrespective to gain.

So what controls an over saturated signal from the sensor ? to the next stage. just asking as im not familar with sensor circuits .

Don

Not sure what you are asking. What is over-saturated signal and what are the conditions causing such signal to emerge?

signal distortion , eg screaming into a microphone ,the pre amp is over saturated with voltage, so a pot pulls it back.

I've seen people screaming into their cameras, yes.

Anti-blooming doesn't help those people.

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Iliah Borg Forum Pro • Posts: 28,756
Re: Exposure vs Exposure
6

john isaacs wrote:

He can talk about Lux all he wants. No one cares.

If no one cares, why would Kodak mention lux 70 times on 24 pages of their "Basic Photographic Sensitometry Workbook" brochure?

It’s the image that matters.

A good image becomes better when exposure is also good.

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bobn2
bobn2 Forum Pro • Posts: 69,811
Re: Exposure vs Exposure
1

Donald B wrote:

Maybe this guy and everyone else on the planet doesnt understand either.

https://www.slrlounge.com/photography-essentials-the-sunny-16-rule/

'That guy' certainly doesn't understand. It's irrelevant whether he does in the case of the article you cite, because it has no bearing on this discussion at all. However, look at the other articles in the series and they are chock full of errors, misunderstandings, fallacies and confusion. Definitely someone to avoid if you actually want to learn the stuff.

As for 'everyone else on the planet', clearly no, because there are a good few that do understand exposure. Some of them have posted on this forum.  Plus, I'd hazard a guess that the majority of people on this planet never use the word 'exposure' and don't have an opinion either way.

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