New exposure concept? Looking for your valued feedback!

[Tim Tucker 2]

mathematically, these are accurate:

Not really, Sunny at f16 is 4x the brightness of Overcast and twice the brightness of Hazy. It's a log scale and will never fit into a linear bar graph.

Absolutely, Tim! But we didn´t start with the knowledge we have now. This isn´t meant to tell people what exact settings to use with which scene luminance. It is meant to show people how these settings correlate, so that they can do exactly what you say.

It doesn't address the fundamental point that I had so much trouble with when I had to *un-learn* the false logic of this type of device, that exposure is the *range of intensities of light that falls on the sensor and produce the image*. It's the light that creates the exposure and the image, the camera simply restricts that range of light intensities so the image you want falls within the range that the sensor can record. f16@1/100 is simply the camera setting you use to achieve this.

Also it's not about *adding* settings but restricting the amount of light and the object of the exercise is to understand how to achieve the same or constant intensity of light at the sensor not how to make it brighter or darker.

This makes far more sense to me, simply understanding the relationship between aperture and shutter speed and how each abstracts the image, then separately the relationship between ISO and available light and how it affects your ability to choose effective camera settings. Nothing more is needed, everything else just confuses:

 

[photo1x1.com]

mathematically, these are accurate:

Not really, Sunny at f16 is 4x the brightness of Overcast and twice the brightness of Hazy. It's a log scale and will never fit into a linear bar graph.

Absolutely, Tim! But we didn´t start with the knowledge we have now. This isn´t meant to tell people what exact settings to use with which scene luminance. It is meant to show people how these settings correlate, so that they can do exactly what you say.

It doesn't address the fundamental point that I had so much trouble with when I had to *un-learn* the false logic of this type of device, that exposure is the *range of intensities of light that falls on the sensor and produce the image*. It's the light that creates the exposure and the image, the camera simply restricts that range of light intensities so the image you want falls within the range that the sensor can record. f16@1/100 is simply the camera setting you use to achieve this.

Also it's not about *adding* settings but restricting the amount of light and the object of the exercise is to understand how to achieve the same or constant intensity of light at the sensor not how to make it brighter or darker.

This makes far more sense to me, simply understanding the relationship between aperture and shutter speed and how each abstracts the image, then separately the relationship between ISO and available light and how it affects your ability to choose effective camera settings. Nothing more is needed, everything else just confuses:

View attachment 169279

Interesting thoughts, Tim, thanks for elaborating. I´ll think about that.
I don´t think though that changing the aperture bar to go from bright to dark would make it easier to understand when shutter speed does the opposite.

 

[Tim Tucker 2]

I don´t think though that changing the aperture bar to go from bright to dark would make it easier to understand when shutter speed does the opposite.

You see this is the problem. You're trying to fit it into your understanding rather than understand what it is you're trying to explain. Exposure is not about controlling the brightness of the image but the brightness of the light that creates the image. It's about consistency of light on the sensor and for that my diagram is the correct way around.

1/4000 @ f1.4 = 1/2000 @ f2.0 = 1/1000 @ f2.8 = 1/500 @ f4 = 1/250 @ f5.6 etc... Is that relationship explained in your diagram or confused?

What happens if I read your chart vertically? F64 @ 1/8000 @ ISO25 for a night shot? F1 @ BULB @ ISO102,400 for bright daylight?

Do the terms Brighter/Darker refer to the image or the light in the scene? How do I know which one refers to which band?

You start with a suggested camera setting for both aperture and shutter speed, it is the one measurement the camera makes against how it displays it. What you need to know is how you can vary that and maintain the suggested exposure, the relationship between aperture and shutter speed against the abstraction that occurs in the image. Then if you can't attain what you want you need to know the relationship of available light to ISO and how that can maintain consistency in your image against the abstraction that occurs with the selection. That's it. There is no diagram that unifies the relationships, they only create mis-understanding.

 

[Designer]

My first thought was doing it proportional, but the problem is it will not work.

In regard to leaving out ISO. I too have thought about that, but then I thought many people will be confused,

You might be able to display this graphically, but the relationship is logarithmic, like the scale on a slide rule.

So you teach people the correct relationship, and it confuses them. Yes, at first it will, but how is continuing to reinforce an incorrect relationship making any progress?

 

[Derrel]

You write, "Keep ISO as low as possible for best results". THAT "advice" is poorly-worded.

 

[photo1x1.com]

You write, "Keep ISO as low as possible for best results". THAT "advice" is poorly-worded.

absolutely - thanks for pointing that out!

 

[photo1x1.com]

My first thought was doing it proportional, but the problem is it will not work.

In regard to leaving out ISO. I too have thought about that, but then I thought many people will be confused,

You might be able to display this graphically, but the relationship is logarithmic, like the scale on a slide rule.

So you teach people the correct relationship, and it confuses them. Yes, at first it will, but how is continuing to reinforce an incorrect relationship making any progress?

Thanks again for your input! It really is appreciated.
The problem is: I have a lot of people asking me e.g. what the difference between 1/30sec and 30sec is. Then I explain with apples how a quarter apple is different to 4 apples and yet they still have issues understanding fractions. I´m not making fun of people here, that´s just the way it is. Talking about logarithmic relationships will probably stop them from taking images altogether. Photography is much easier than that.
I try to keep in mind that not all people have the same intellectual capabilities that you have and so in my experience, there is a need for explaining things in a way that people can use it. So far I have really good feedback on my style of teaching. Many people have struggled for months and now seem to really get the hang of it. I do know that feedback is subjective and I am realistic enough that some people will say "wooooow, that´s great" - even if it is the worst thing they ever saw.
I hope that makes at least a bit of sense

 

[TreeofLifeStairs]

You write, "Keep ISO as low as possible for best results". THAT "advice" is poorly-worded.

I’ve heard this before but I don’t understand why it’s not good advice. I would interpret it to mean that as long as the aperture and SS are set correctly to adequately take the picture (meaning DoF is appropriate and desirable, and no motion blur) then what would be the reason to increase the ISO? Why would I intentionally set the ISO higher when I could set it lower and still capture the shot?

 

[photo1x1.com]

I don´t think though that changing the aperture bar to go from bright to dark would make it easier to understand when shutter speed does the opposite.

You see this is the problem. You're trying to fit it into your understanding rather than understand what it is you're trying to explain. Exposure is not about controlling the brightness of the image but the brightness of the light that creates the image. It's about consistency of light on the sensor and for that my diagram is the correct way around.

1/4000 @ f1.4 = 1/2000 @ f2.0 = 1/1000 @ f2.8 = 1/500 @ f4 = 1/250 @ f5.6 etc... Is that relationship explained in your diagram or confused?

What happens if I read your chart vertically? F64 @ 1/8000 @ ISO25 for a night shot? F1 @ BULB @ ISO102,400 for bright daylight?

Do the terms Brighter/Darker refer to the image or the light in the scene? How do I know which one refers to which band?

You start with a suggested camera setting for both aperture and shutter speed, it is the one measurement the camera makes against how it displays it. What you need to know is how you can vary that and maintain the suggested exposure, the relationship between aperture and shutter speed against the abstraction that occurs in the image. Then if you can't attain what you want you need to know the relationship of available light to ISO and how that can maintain consistency in your image against the abstraction that occurs with the selection. That's it. There is no diagram that unifies the relationships, they only create mis-understanding.

Thanks again, Tim. I really appreciate the time you put into this and it definitely keeps me thinking.
I´m still not convinced on "mirroring" the aperture bar. I have read several abstracts about the human brain. Maybe this is just one example that things that seem logical for one, are the opposite for the other. However, I will try to investigate into that and ask as many people as I can to get some statistical relevant data. I could be wrong on this one, so I´d rather do some more "research".

Good point on the terms Brighter/Darker, thanks!!!

Those suggested camera settings weren´t actually meant like that. I was just going for an example that would create decent image brightness, and would leave room for change. In regard to misunderstanding, I´m afraid I have to disagree. My reply to Designers post above would work here too. To most people a diagram that isn´t scientifically correct explains more than a paragraph of words that are. Some people are visual learners, others are auditory,...

 

[photo1x1.com]

You write, "Keep ISO as low as possible for best results". THAT "advice" is poorly-worded.

I’ve heard this before but I don’t understand why it’s not good advice. I would interpret it to mean that as long as the aperture and SS are set correctly to adequately take the picture (meaning DoF is appropriate and desirable, and no motion blur) then what would be the reason to increase the ISO? Why would I intentionally set the ISO higher when I could set it lower and still capture the shot?

Thanks, TreeofLifeStairs, but I think the wording is really sub-par. What are best "results"? You interpreted it correctly, but will everybody do?
For now I have changed it to "Keep ISO on base level whenever possible for best image quality". But then image quality isn´t only noise and dynamic range. I´ll keep thinking
Thanks again for your input!

 

[480sparky]

You write, "Keep ISO as low as possible for best results". THAT "advice" is poorly-worded.

I’ve heard this before but I don’t understand why it’s not good advice............

It leads novices to believe they shouldn't be using ISO 400 or higher. This causes them to use wider apertures than they'd like, or slower shutter speeds that are too slow for the subject or for the photographer to induce camera blur. I shudder to think how many great images have been lost due to this poor advice.

 

[Designer]

"Photography is much easier than that."

Exactly right. If people are so dull as to not understand fractions, then why are you bothering to attempt to teach the finer points of photography? Wouldn't it be much simpler and faster to simply tell them to "put it in green auto and press the button", rather than all that aperture and shutter speed stuff?

 

[Tim Tucker 2]

I totally get your point about the way we learn, and I totally understand that you need to avoid explaining it in terms of a log scale because that really does confuse beginners. It was noted because it makes it impossible to convert the relationships to a linear scale that makes sense.

I was just going for an example that would create decent image brightness

The way I read this I feel that you are still not getting the concept of exposure or how to reduce it to the simplest terms. Your diagram looks at variations in the levels of light and the brightness of the image both as variables but fails to provide any constant or fixed point, the aim or what exposure seeks to achieve.

To simplify talk only about a camera generated jpeg, this removes any PP effects.

In a camera jpeg displayed on your screen or the LCD on the back of the camera the colours and values of light are fixed on the RGB scale from 0-255 and mid grey is 128. This requires a fixed amount of light to fall on the sensor in all cases to produce that tone. It is your constant.

If you're trying to explain the abstract to students then you need to create a fixed point around which everything else moves and this is it. The concept of image brightness itself is an abstract one and not really the function of exposure, exposure and visualisation is about being able to reproduce consistently the tones you want in the image at the brightness you want. If you want a darker image then you need to know how to produce that darker grey, but essentially you are still aiming to produce a fixed and known tone which requires a fixed and known amount of light. So we have two stages, teaching how to convert mid grey in a scene as mid grey on the sensor, then how to vary exposure to produce mid grey as a darker grey.

If you work with mid grey then you reference directly how the meter in your camera works. So we have a mid grey card in bright sunlight and one on a dark night. The aim of exposure is to ensure that the amount of light reflected off the card, through the lens and onto the sensor is exactly the same in both cases. The only information the camera provides through it's meter are the settings for shutter speed, aperture and ISO to achieve this. Again we are at the fixed constant.

We have four variables in this model, the amount of light reflected off the card, the aperture, shutter speed and ISO. So we nw see how they relate if our aim is to produce the same fixed signal at the sensor, mid grey.

You can't explain this in one diagram, it requires two at least. As an abstract why not think in abstract terms? At the moment you are thinking only of the absolute as in the settings themselves and how to make them add to a constant, but they don't. If the constant is the fixed level of light hitting the sensor then why not use a model that shows how to subtract light so what is left is constant? Why are you using absolute scales as the actual settings? If you use abstract scales such as Increase/Decrease you avoid the log scale because you avoid using any defined unit.

Try something like this, but you still need a separate diagram to explain the effects of the selections you make which can now be your original minus the *Scene Luminance* the exact way you had it:

 

[Braineack]

I’ve heard this before but I don’t understand why it’s not good advice. I would interpret it to mean that as long as the aperture and SS are set correctly to adequately take the picture (meaning DoF is appropriate and desirable, and no motion blur) then what would be the reason to increase the ISO? Why would I intentionally set the ISO higher when I could set it lower and still capture the shot?

what if you're using flash and need a good blend of ambient and flash exposure -- shoot at 100 iso and you might end up with bright faces [with 1/1 power] on a pitch black BG. shoot at iso 800 and you might end up with well blended subjects to the BG.

what if shooting at iso 100 requires a SS that's simply too slow and introduces blur? But shooting at iso 1600 gives you 4 stops of speed and better results?

not all sensors are iso invariant and it goes both ways; so it's really not a great "rule".

Like I mentioned above, I have a min. shutter speed set at 1/160, last weekend I was shooting in a dark warehouse using a 3.5-5.6 lens in A mode -- for what i considered best results--since I was also in auto-iso--most my shots ended up between 2800-6400iso.

Sure I could have shot at iso 100 and pushed it 5 stops to 3200 in post, but I would have no more latitude after that and really pushing things and the exposure in-camera is a guess since the shot would look pitch black in the preview. And since the images look identical after pushing in post, how is shooting at 100 giving me better results. it really isn't.

Or I could have shot at 100 and dropped the shutter to something like 1/6sec, but then all my shots would have been blurry --- is that best results?

 

[480sparky]

...... It's a log scale and will never fit into a linear bar graph............

Explain slide rules then.