Triangle?

[SmilerGrogan]

The larger point and why I even got involved in this preposterous and pointless debate is that you think it's wonderful fun to insult and belittle a working photographer of tremendous talent because he doesn't parrot your functionally worthless and illogical explanation of exposure.

To add extra entertainment value you people found it necessary to add a snide question about what Roger thinks with the expectation that Mr. Cicala will read your words and immediately kick Zach to the curb.

If there is a god (or even if there is not) Mr. Cicala will have the presence of mind to see through your vile machinations and dismiss your insinuations with the contempt they are due.

What is it about reality that so triggers you?

Well, since you ask, those fallacies are what triggers me. “You don’t like sloppy terminology, therefore you don’t like REALITY!”

Not wanting to attribute malignant intentions to you, I hope that that such fallacies are accidental.

Standards, from thread pitch on pipes to number of shrimp in a pound, allow people working together to share a common set of terms and expectations. They’re not handcuffs or your mom telling you you’re a bad boy. They’re just ideas on paper that some people find helpful.

They are more helpful when they are followed. That’s why many of them are accompanied by instructions for conformance testing.

As an example, I and other people have been working on the upcoming ISO 18181. We certainly hope that you and others will find it useful, but if you want to write your own encoder or decoder for it, I would personally request that you please make it compatible.

And ISO may not be part of your idea of what “exposure” means but that’s because of where you got your definition of the term.

Why are you implying that it’s only my definition? It’s the definition used by the standard itself, the definition that those people working together have agreed on. Using that definition, to say that ISO is part of exposure is somewhat similar to saying that a CIPA battery life rating is part of a camera’s power consumption. They are certainly related (the higher the exposure or power consumption, the lower the ISO or the CIPA rating), but to say that the former is part of the latter is kind of a stretch.

But since you appear to object to that definition of exposure, it begs the question: what is yours?

 

[J A C S]

The larger point and why I even got involved in this preposterous and pointless debate is that you think it's wonderful fun to insult and belittle a working photographer of tremendous talent because he doesn't parrot your functionally worthless and illogical explanation of exposure.

What is exposure?

 

[spider-mario]

The larger point and why I even got involved in this preposterous and pointless debate is that you think it's wonderful fun to insult and belittle a working photographer of tremendous talent because he doesn't parrot your functionally worthless and illogical explanation of exposure.

He may be very talented but that doesn’t mean that one cannot give constructive criticism. Speaking of which, I can’t speak for the others but personally, I would warmly welcome constructive interventions from you too.

Belittling or insulting him was not the intent. You don’t have to take it personally on his behalf.

To add extra entertainment value you people found it necessary to add a snide question about what Roger thinks with the expectation that Mr. Cicala will read your words and immediately kick Zach to the curb.

Where did that happen? I scouted the thread with no success in finding where this allegedly occurred.

If there is a god (or even if there is not) Mr. Cicala will have the presence of mind to see through your vile machinations and dismiss your insinuations with the contempt they are due.

What insinuations? I think the points have been made rather explicitly by now, unless you are yourself insinuating that there are more.

 

[Christof21]

The real numbers do not really matter because nobody uses as a guidance. What is really elegant is that it shows that only some combinations are possible and are often a matter of compromise.

What makes the other combinations not “possible”?

It would not give the same lightness.

 

[SmilerGrogan]

Photography is the art and science of recording differences between tone and color.

"Brightness," according to the anti-ISO crowd's favorite source Wikipedia, is the arithmetic mean μ of the red, green, and blue color coordinates

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

But one important thing remains. It shows that these 3 parameters are the pillars for exposure (in fact brightness).

Causing user confusion between brightness and exposure seems to be a major problem with the "exposure triangle" notion.

 

[SmilerGrogan]

Exposure is the amount of light falling on the subject. That's why when you're photographing bears in identical light, the camera settings will be the same whether it's grizzly or polar.

The problem here is that most of you use reflected or evaluative metering which can't measure the light falling on the subject. Instead these meters use algorithms in an attempt to deduce the incident light levels from whatever is hitting their metering pixels. What you're getting is a recommendation, not a measurement.

Even if you use an incident meter, you're still relying on what Sekonic or Gossen engineers believe to be the best settings based on the data collected—so that's not really exposure either, it's just another recommendation.

If it's mediated by human thought, action, or mechanical gizmo, it's not exposure, it's just guesswork by people of greater or lesser talent.

The larger point and why I even got involved in this preposterous and pointless debate is that you think it's wonderful fun to insult and belittle a working photographer of tremendous talent because he doesn't parrot your functionally worthless and illogical explanation of exposure.

What is exposure?

 

[J A C S]

Exposure is the amount of light falling on the subject.

No, it is not. Even it it were, there is no way the ISO on you camera would affect it.

 

[Iliah Borg]

"Brightness," ... is the arithmetic mean μ of the red, green, and blue color coordinates

Why do you resort to partial quoting?

First, https://en.wikipedia.org/wiki/Brightness opens with quite a different proposition.

Second, arithmetic mean is not brightness even in the obsolete meaning of this term, it's how sloppy image editors edit a parameter they call "brightness".

Third, to use arithmetics of that sort, you need a colorimetric RGB colour space, and raw is not defined in such a space, nearly always.

Forth, Wyszecki and Stiles define brightness as an attribute of a visual sensation according to which a given visual stimulus appears to be more or less intense; or, according to which the area in which the visual stimulus is presented appears to emit more or less light, and range variation in Brightness from “bright” to “dim”.

Brightness is a presentation attribute, as it depends not just on image properties, but also heavily relies upon the viewing conditions.

Brightness, by definition, is a psychophysical non-measurable characteristic.

What good and scientific sources can you cite in support for your proposition?

 

[Austinian]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

 

[alanr0]

The larger point and why I even got involved in this preposterous and pointless debate is that you think it's wonderful fun to insult and belittle a working photographer of tremendous talent because he doesn't parrot your functionally worthless and illogical explanation of exposure.

It's not spider-mario's definition of exposure. As he says, it has made its way into multiple international standards. If you don't wish to shell out for the relevant ISO documentation, Wikipedia is a popular alternative.

When discussing photographic science and technology, it helps to have (and use) consistent and widely agreed definitions. This facilitates worthwhile and constructive discussion.

https://en.wikipedia.org/wiki/Film_speed#Measurements_and_calculations

To add extra entertainment value you people found it necessary to add a snide question about what Roger thinks with the expectation that Mr. Cicala will read your words and immediately kick Zach to the curb.

If there is a god (or even if there is not) Mr. Cicala will have the presence of mind to see through your vile machinations and dismiss your insinuations with the contempt they are due.

Zach Sutton may be an excellent photographer, but the article is sloppily written in places. I am sure Roger Cicala is capable of making his own judgements.

I have no problems with Mr Sutton's discussion around the effects of changing aperture, which is the main point of the article. The image sequence showing DoF control will be helpful to beginners, and the opening paragraph is a perfectly acceptable, if rather chatty introduction.

The exposure triangle illustration is one of the less objectionable versions, although I suspect that the upper "shutter speed" arrowhead was inadequately attached and has slipped down behind the triangle. Unfortunately, the very term "Exposure Triangle" is sufficient to raise hackles here. As it happens, the author does not actually use the triangle concept, or discuss what it means, beyond there being 3 parameters to consider, so he gets a pass from me on this.

The paragraph following is rather more contentious.

Properly exposing an image will always come down to three main settings – Shutter Speed, Aperture, and ISO. These three settings are known as the exposure triangle. To put it very simply, the exposure of an image will be the same if you adjust these settings in correlation with each other.

This is shaky ground.

For example, if you need to increase your shutter speed, you can adjust it by two 2/3 stops (so two clicks on your dial) to something faster, and open up your aperture by two clicks of the wheel to match the exposure from the previous shot.

OK, no change to exposure, so he dodged a bullet there.

While each of these settings will alter the image’s exposure, they each have adverse effects on your image in other places.

Poor choice of words.

The effects on image quality are not necessarily adverse. At the very least, the "adverse" direction depends on subject matter and artistic intent. Sometimes I want deep depth of field. Other times shallow. For portraits a modest splash of spherical aberration can even be desirable.

Strictly speaking, ISO sensitivity or ISO speed does not change exposure, which depends only on luminance from the subject, exposure time, lens transmission and aperture.

Today, we’ll be focusing on aperture, with shutter speed and ISO to come in future articles.

OK, so just another internet article as far as I am concerned, but some folks may be sharpening their pitchforks anticipating more concrete heresy when the third article appears.

Time to stock up with popcorn.

--
Alan Robinson

 

[Iliah Borg]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Most image editors implement "brightness" manipulation in a sloppy, non-colorimetric way, causing colour shifts. The trick is not to use oversimplified sliders, not to play fast and dirty. But that implies some image editing skills. Those who define brightness based on their experience with said sad brightness sliders will never believe you.

For a raw, when everything is pretty much linear over the useful dynamic range, increasing or decreasing ISO and same way, exposure, results in linear magnitude scaling (not lightness, as it is not applicable, strictly speaking, but magnitude). All that follows depends on the implementation of mapping that magnitude to lightness in a raw converter, and operator's skills with the converter.

 

[D Cox]

Exposure is the amount of light falling on the subject.

No, it is not. Even it it were, there is no way the ISO on you camera would affect it.

Nor would the aperture or the shutter time.

However, I agree with Mr Grogan that there are advantages to using incident light metering, especially in the studio. An incident light flash meter is very useful.

But exposure is the amount of light falling on the film or the sensor, not the amount falling on the subject. If you use an incident meter, it will give you a number for the amount falling on the subject, and using the dials on the meter you can work out what f number to use for good results.

The point about bears is highly relevant to product photography. You don't want black products and white ones to both come out mid grey.

 

[Austinian]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Most image editors implement "brightness" manipulation in a sloppy, non-colorimetric way, causing colour shifts. The trick is not to use oversimplified sliders, not to play fast and dirty. But that implies some image editing skills. Those who define brightness based on their experience with said sad brightness sliders will never believe you.

For a raw, when everything is pretty much linear over the useful dynamic range, increasing or decreasing ISO and same way, exposure, results in linear magnitude scaling (not lightness, as it is not applicable, strictly speaking, but magnitude). All that follows depends on the implementation of mapping that magnitude to lightness in a raw converter, and operator's skills with the converter.

Very interesting. How can the user of the raw processor(s) best detect and avoid or minimize such color shifts? Which consumer raw converters perform best in this respect?

 

[alanr0]

Exposure is the amount of light falling on the subject. That's why when you're photographing bears in identical light, the camera settings will be the same whether it's grizzly or polar.

That would be subject illuminance, not exposure.

if "Exposure is the amount of light falling on the subject", how does that depend on any changes you make to your camera?

J A C S, post: 64187702, member: 1163177"]

SmilerGrogan, post: 64187702, member: 1163177"]
The larger point and why I even got involved in this preposterous and pointless debate is that you think it's wonderful fun to insult and belittle a working photographer of tremendous talent because he doesn't parrot your functionally worthless and illogical explanation of exposure.

What is exposure?

[/QUOTE]
[/QUOTE]

 

[D Cox]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Think about it. He's quite right. If he image is too bright on the monitor, some of the tones will be crowded together, making the image less realistic and harder to decipher.

 

[Iliah Borg]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Most image editors implement "brightness" manipulation in a sloppy, non-colorimetric way, causing colour shifts. The trick is not to use oversimplified sliders, not to play fast and dirty. But that implies some image editing skills. Those who define brightness based on their experience with said sad brightness sliders will never believe you.

For a raw, when everything is pretty much linear over the useful dynamic range, increasing or decreasing ISO and same way, exposure, results in linear magnitude scaling (not lightness, as it is not applicable, strictly speaking, but magnitude). All that follows depends on the implementation of mapping that magnitude to lightness in a raw converter, and operator's skills with the converter.

Very interesting. How can the user of the raw processor(s) best detect and avoid or minimize such color shifts?

On a Mac, one can use the standard DigitalColor Meter app, to check that only "a" an "b" of Lab are changed when "brightness" or "exposure" sliders are moved. Should be something similar for Windows.

Which consumer raw converters perform best in this respect?

ACR/Lr in PV2 (2010) mode.

Please see https://www.rawdigger.com/howtouse/overriding-raw-converter-default-adjustments-settings for a detailed discussion. You may want to start from "Practical Part: How You Can Override Default Adjustments".

A shortcut for ACR and Lr was introduced in FastRawViewer 1.5.2 and is maintained in more recent versions. Details are on https://www.fastrawviewer.com/blog/FastRawViewer-1-5-2-release-adobe-accurate-tone-rendeding-support - "New Settings to Support Highly Linear Mode" section.

 

[Austinian]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Think about it. He's quite right. If he image is too bright on the monitor, some of the tones will be crowded together, making the image less realistic and harder to decipher.

If images are too bright on the monitor, I'd turn down the backlight. I have my calibration set to 80 cd/m2 according to my colorimeter.

If important features are significantly overexposed, the image is trashed.

But if a photograph was taken in a very low light environment such that exposure was greatly inadequate, and it wasn't possible to discern details at the default raw processor's settings, I would certainly want to increase lightness/"brightness" in order to make the image at all usable.

 

[Austinian]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Most image editors implement "brightness" manipulation in a sloppy, non-colorimetric way, causing colour shifts. The trick is not to use oversimplified sliders, not to play fast and dirty. But that implies some image editing skills. Those who define brightness based on their experience with said sad brightness sliders will never believe you.

For a raw, when everything is pretty much linear over the useful dynamic range, increasing or decreasing ISO and same way, exposure, results in linear magnitude scaling (not lightness, as it is not applicable, strictly speaking, but magnitude). All that follows depends on the implementation of mapping that magnitude to lightness in a raw converter, and operator's skills with the converter.

Very interesting. How can the user of the raw processor(s) best detect and avoid or minimize such color shifts?

On a Mac, one can use the standard DigitalColor Meter app, to check that only "a" an "b" of Lab are changed when "brightness" or "exposure" sliders are moved. Should be something similar for Windows.

Which consumer raw converters perform best in this respect?

ACR/Lr in PV2 (2010) mode.

Please see https://www.rawdigger.com/howtouse/overriding-raw-converter-default-adjustments-settings for a detailed discussion. You may want to start from "Practical Part: How You Can Override Default Adjustments".

Thank you, I will have a careful look at that link. Bookmarked.

 

[knickerhawk]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Most image editors implement "brightness" manipulation in a sloppy, non-colorimetric way, causing colour shifts. The trick is not to use oversimplified sliders, not to play fast and dirty. But that implies some image editing skills. Those who define brightness based on their experience with said sad brightness sliders will never believe you.

For a raw, when everything is pretty much linear over the useful dynamic range, increasing or decreasing ISO and same way, exposure, results in linear magnitude scaling (not lightness, as it is not applicable, strictly speaking, but magnitude). All that follows depends on the implementation of mapping that magnitude to lightness in a raw converter, and operator's skills with the converter.

Very interesting. How can the user of the raw processor(s) best detect and avoid or minimize such color shifts?

On a Mac, one can use the standard DigitalColor Meter app, to check that only "a" an "b" of Lab are changed when "brightness" or "exposure" sliders are moved.

I think you meant to say "a" and "b" are NOT changed when "brightness" or "exposure" sliders are moved".

Should be something similar for Windows.

Which consumer raw converters perform best in this respect?

ACR/Lr in PV2 (2010) mode.

Please see https://www.rawdigger.com/howtouse/overriding-raw-converter-default-adjustments-settings for a detailed discussion. You may want to start from "Practical Part: How You Can Override Default Adjustments".

A shortcut for ACR and Lr was introduced in FastRawViewer 1.5.2 and is maintained in more recent versions. Details are on https://www.fastrawviewer.com/blog/FastRawViewer-1-5-2-release-adobe-accurate-tone-rendeding-support - "New Settings to Support Highly Linear Mode" section.

Yes, and I'm a fan of the Margulis "neutral" conversion approach, but your reader should bear in mind that this just postpones the problem to Photoshop, where you can easily wipe out the good intentions of the neutral conversion by carelessly applying the needed tonal adjustments there. In PS you should probably work in Lab mode and use L channel adjustments if you're making big tonal moves and want to avoid color shifts. Fading to luminosity blend mode is a pretty hit-and-miss solution when you're working in a RGB space in PS.

 

[Iliah Borg]

Raising or lowering "brightness" usually has a negative effect on color and tone relationships making a picture less photographic and harder to decipher.

You're welcome to believe that (and other things) but I do not.

Most image editors implement "brightness" manipulation in a sloppy, non-colorimetric way, causing colour shifts. The trick is not to use oversimplified sliders, not to play fast and dirty. But that implies some image editing skills. Those who define brightness based on their experience with said sad brightness sliders will never believe you.

For a raw, when everything is pretty much linear over the useful dynamic range, increasing or decreasing ISO and same way, exposure, results in linear magnitude scaling (not lightness, as it is not applicable, strictly speaking, but magnitude). All that follows depends on the implementation of mapping that magnitude to lightness in a raw converter, and operator's skills with the converter.

Very interesting. How can the user of the raw processor(s) best detect and avoid or minimize such color shifts?

On a Mac, one can use the standard DigitalColor Meter app, to check that only "a" an "b" of Lab are changed when "brightness" or "exposure" sliders are moved.

I think you meant to say "a" and "b" are NOT changed when "brightness" or "exposure" sliders are moved".

I'm sorry, and you are right. Thank you very much for catching this.

On a Mac, one can use the standard DigitalColor Meter app, to check that only L (of Lab) is changed when "brightness" or "exposure" sliders are moved, while "a" and "b" stay approximately the same.

Should be something similar for Windows.

Which consumer raw converters perform best in this respect?

ACR/Lr in PV2 (2010) mode.

Please see https://www.rawdigger.com/howtouse/overriding-raw-converter-default-adjustments-settings for a detailed discussion. You may want to start from "Practical Part: How You Can Override Default Adjustments".

A shortcut for ACR and Lr was introduced in FastRawViewer 1.5.2 and is maintained in more recent versions. Details are on https://www.fastrawviewer.com/blog/FastRawViewer-1-5-2-release-adobe-accurate-tone-rendeding-support - "New Settings to Support Highly Linear Mode" section.

Yes, and I'm a fan of the Margulis "neutral" conversion approach, but your reader should bear in mind that this just postpones the problem to Photoshop, where you can easily wipe out the good intentions of the neutral conversion by carelessly applying the needed tonal adjustments there. In PS you should probably work in Lab mode and use L channel adjustments if you're making big tonal moves and want to avoid color shifts. Fading to luminosity blend mode is a pretty hit-and-miss solution when you're working in a RGB space in PS.

Yes, we must learn our way around image editing.