Exposure Triangle

[Robin Usagani]

exposure triangle is basic though. This is beyond basics section

 

[KmH]

I have never liked the triangle analogy either, for a variety of reasons, and refer to it as the 'exposure adjustment triad'.

Each person able to come to grips with manually controlling a camera eventually develops their own mental model of how the 3 exposure values relate to one another.

Another evolution in that mental model has to take place when/if strobed light is added to the photographers bag-of-tricks.

 

[RacePhoto]

Just as a for instance, suppose we forget ISO for the moment.

You can no more forget ISO than you can shutter speed or aperture. There ARE three factors involved, not two. Each with distinct advantages and disadvantages.

I wouldn't stand for it, if I were you. You should drop everything else and devote your life to destroying this terrible idea of the "exposure triangle". It's truly that important.

That got me laughing, and I agree.

Or go analog, with film, it's what you loaded, so much simpler, you can't change on the fly. :thumbup:

It's really a simple concept change one and the others are altered. I can't believe there's some controversy or big forum conflict over basic physics?

Let me help:

1) Canon or Nikon?
2) RAW or JPG?
3) UV filter protection or not?
4) sRGB or RGB?
5) What makes someone a "professional" photographer?
6) Who is really "America's Team? Packers or Dallas

I can't believe people are arguing about a simple concept used to teach how three factors interact to control Exposure!

It's all wrong anyway, it should be a

Reuleaux triangle.

 

[tirediron]

DOWN WITH TRIANGLES!!!

and while we're on the topic, I'm not very fond of ovals either...

 

[Solarflare]

I honestly have no clue anymore what this thread is all about.

The exposure triangle is very simple and basic - raise one of the three parameters, then you have to lower one of the two other parameters by the same amount, or end up with an overexposed picture. And vice versa.

What is there to oppose ? Its like opposing the rule of proportion. You dont need to use it to compute, but you need to know what it represents.

go analog, with film, it's what you loaded, so much simpler, you can't change on the fly. :thumbup:

You cant change it on the fly on digital cameras either, it usually involves ugly menu surfing on really every digital camera I've checked out so far.

 

[Buckster]

go analog, with film, it's what you loaded, so much simpler, you can't change on the fly. :thumbup:

You cant change it on the fly on digital cameras either, it usually involves ugly menu surfing on really every digital camera I've checked out so far.

LOL! You're so funny ...!!

1. Push ISO button next to shutter button.
2. Spin wheel to new ISO.

Most of us can do it without even taking our eye from the viewfinder of our DSLR.

As for changing ISO in the middle of a shoot with film, that's what film backs are for.

 

[unpopular]

The "exposure triangle" teaches exposure compensation, but does not teach exposure control.

I think it was first illustrated by Bryan Peterson, so so what can you realistically expect?

 

[amolitor]

RacePhoto:

"I can't believe people are arguing about a simple concept used to teach how three factors interact to control Exposure!"

My point is that the exposure triangle doesn't teach anything, and it most certainly does not teach how the three factors interact. It's one of those things that looks great once you've grasped the incredibly trivial details of this interaction, but it actually makes things worse before you understand these details. I suspect that the "exposure triangle" is a substantial factor in why newbies these days have trouble grasping exposure, which SHOULD take about 2 minutes to explain, an hour to understand fully, and a week to put in to practice. And yet, we see newbies struggling.

Everyone reading this should care about these pedagogical devices, since when they're bad and confusing, they generate cluenless newbies that clutter up forums like this one with their confusion over simple simple things. Do you enjoy reading these sad postings from newbies who "have been struggling with exposure and it's soooooo confusing" with their terrible overexposed pictures? I don't. I don't like the clutter, and I also want to help them as individuals AND as a group.

Kill The Exposure Triangle.

 

[480sparky]

.............You cant change it on the fly on digital cameras either, it usually involves ugly menu surfing on really every digital camera I've checked out so far.

I just press the ISO button, then spin the rear command dial.

100 to 25,600 in .37 sec.

 

[480sparky]

.............Kill The Exposure Triangle.

And replace it with.......... The Amolitor Method of Exposure Control?

How's that go, again?

 

[RacePhoto]

And this folks is what "trolling" is all about. Catching a whole group of people in a forum, hook, line and sinker, into responding to some meaningless debate.

:hail: amolitor you deserve an award for this one.

 

[amolitor]

Well, sparky, I don't have a simple graphic that explains it, although I do have a slightly complicated one. It's pretty hard to compress 3 factors on to a 2 dimensional medium in any simple way. Maybe there's a good way to do it in this case, but I haven't come across it yet.

I generally just use words to explain exposure, they work pretty well, luckily.

 

[unpopular]

... or the zone system

I just don't understand at all why people, ordinary people, not rocket scientists, were able to learn basic exposure control 10 years ago. We had AE then. We had multisegment metering. Yet, people could understand the concept of 1:1 ratios. I know. Those advanced civilizations of the past!

 

[tirediron]

...My point is that the exposure triangle doesn't teach anything, and it most certainly does not teach how the three factors interact...

No, and nor is it meant to; it's simply a graphical representation, which, in the Beginner's Photography courses that I have taught, the majority of my students have found very useful. Your mileage may vary.

 

[Ysarex]

Just as a for instance, suppose we forget ISO for the moment.

Imagine a graphic of a teeter-totter, a see-saw, or a balance scale. Label one side "shutter speed" and the other "aperture", and then write underneath it "keep the scale balanced to keep the exposure the same". Now we see clearly and unambiguously (assuming we have proper labels) that if we make the shutter speed faster, we must make the aperture wider, and vice versa. It's an actual geometrical model of what's going on. The Exposure Triangle seems to be an attempt to extend the balance scale picture to include ISO, and it's failed completely.

Or at any rate, I have not seen a single explanation that managed to get any further than "here's the exposure triangle. These three settings are interconnected. Let's look at some examples!"

You'd be surprised how much trouble some people have understanding exposure. I have struggled for years trying to figure out why this is so and to come up with effective instructional models.

I don't like the triangle model either. It was introduced with the advent of digital photo to deal with the new digital facility to alter ISO frame to frame. Before digital you put a roll of film in the camera and the ISO was immediately locked down. So you could then move on to your see-saw model, but that's also inadequate.

Both the see-saw and the triangle models fail to account for another variable -- fluctuating light intensity which is further complicated by variations in contrast, and subject reflectance properties. The models also fail to account for the behavior of the "magical meter" or the need for a measuring tool.

One of the problems with any of these models is that they fail to account for variations in function between the parameters as Solarflare was pointing out. The shutter speed and aperture both function like valves that permit you to control the "flow rate" of light as a valve would control water and yet the ISO has no corollary function. This may be part of why you're objecting to the triangle and it's one reason I don't like it. You place each variable on equal sides of a triangle but one of them has a uniquely different function -- confusion follows. At least the triangle needs to have the base (ISO) color coded or marked as different than the two sides (shutter/aperture). And then there needs to be a way to add in the variable of light intensity: Hey! I've got it! And this model has built-in incentive as well $$$$!

I have witnessed time and again adults learn to manipulate a camera's controls with moderate success (zero the meter by changing one or another of the triangle variables) but still not really understand what's going on. It's like music. I've met many accomplished musicians who can play an instrument and even read music and yet devolve into stammering idiots when asked why there are two missing black keys on the piano keyboard.

Joe