Exposure Triangle

[unpopular]

"Zero The Meter" is precisely the problem.

 

[Steve5D]

Yes, yes, I get that it captures the idea that the three things are interconnected. My point is that it seems to capture nothing whatsoever ELSE.

Is it supposed to?

I see no reason for it to be complicated...

 

[Helen B]

The triangle doesn't make much sense to me either. Too many questions about what means what. What about a simple circle, with the circumference divided into four arcs (brightness, sensitivity, time, aperture)? The circle must be complete, so changing the length of one arc requires a change in one or more of the other three? (If one really feels that a graphic is necessary)

 

[amolitor]

I use a bucket analogy:

You want to fill a bucket with light. Aperture is hose size, shutter speed is how long to stand there filling, and ISO is how big the bucket is.

The meter tells you how to fill the bucket up halfway. If you want it less full, that's the same thing as darker. If you want it more full, that's lighter.

Aperture is dumb and goes backwards, smaller numbers mean a bigger hose.

DONE.

Words. They work.

 

[Buckster]

Aperture is dumb and goes backwards, smaller numbers mean a bigger hose.

No, they don't. They're fractions.

 

[amolitor]

Oh, smaller numbers don't mean a bigger hose? So f/2.8 lets in LESS light then f/5.6? Shoot, this is all new stuff. Let me take notes.

All the stuff between the colon and the word "DONE" is my explanation targeted at newbies, just FYI. Again, for those of you not keeping up: I understand exposure just fine, thanks.

 

[MTVision]

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.

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.

You don't have to menu surf with the d5100 either. You can assign ISO to the Fn button then hold that button and spin the wheel....

 

[unpopular]

I agree with Helen. The Exposure triangle does not account for the very thing it is intended to illustrate: exposure. Where does the subject come into the picture? Would a lighter or darker than middle grey subject change the shape of the triangle?

 

[unpopular]

You don't have to menu surf with the d5100 either. You can assign ISO to the Fn button then hold that button and spin the wheel....

You don't even have to with the very menu-centric a350!

 

[manaheim]

I use a bucket analogy:

You want to fill a bucket with light. Aperture is hose size, shutter speed is how long to stand there filling, and ISO is how big the bucket is.

The meter tells you how to fill the bucket up halfway. If you want it less full, that's the same thing as darker. If you want it more full, that's lighter.

Aperture is dumb and goes backwards, smaller numbers mean a bigger hose.

DONE.

Words. They work.

I agree with all of what you're saying except the last part. Words kinda don't work... at least not without other supporting elements.

Look at what you just did... you created a word PICTURE with your bucket analogy.

As I mentioned, people are very visual. What you've done is created something people can visualize. If words really worked, then you would say...

"Aperture is the hole that allows light to transfer through the lens to the camera. ISO is the sensitivity of the sensor/film to that light. Shutter time is the length of time you allow the shutter to remain open and expose the light to the sensor or film. The higher the ISO, the more sensitive, therefore the less light it needs to expose the image. The wider the aperture, the more light goes to the sensor, the less time it needs to expose the image. All of these things are inter-related, so one affects the other."

Clearly if you said THAT to someone new to this they would look at you like you just offered them a lightly grilled squirrel. Whereas your WORD PICTURE forms a nice mental illustration.

The triangle is evidently another form of illustration- though one that appears to be less useful to some folks- so perhaps yours is better, which is cool. I certainly like your word picture very much and plan to use (steal) it. There may be better ones. But everyone thinks differently, so for some the triangle might make more sense than your bucket analogy.

 

[amolitor]

You (everyone who likes) should, of course, feel free to use my word (picture) as you see fit. I think it's pretty decent myself!

 

[unpopular]

I am almost 100% certain you did not invent that analogy...

 

[amolitor]

It has to have been invented by many people all over, especially since it is only very very slightly an analogy. A sensor damn near is a collection of buckets for collecting light in. ISO is the size of the bucket, shutter speed and aperture are pretty much exactly the same thing as a hose of variable diameter and duration, except for light instead of water.

If I didn't steal it wholesale, I probably stole all the parts. It's been, uh, 30 years, so I've collected a lot of mental detritus on the subject. All our ideas are products of the stuff we've picked up along the way, eh?

 

[Ysarex]

I am almost 100% certain you did not invent that analogy...

I've been using it for at least 30 years. In mine we're in the lab at the darkroom sink. The aperture is the valve in the faucet which can be adjusted. Different size graduates are different ISO values, etc. I'd stand there with a group of new Photo I students and actually run the water.

Joe

Edit: "they would look at me like I just offered them a lightly grilled squirrel."

 

[unpopular]

ISO is the size of the bucket

WHOA! You mean changing ISO changes the physical characteristics of the sensor element?

I did not realize that! Here I thought it simply increased analog amplification...

No. This is not accurate even with film.