Aperture, ISO, Shutter Speed, Exposure Triangle Simplified....

[sk66]

I see many posts with questions about the Triangle, or statements from individuals to the effect of "it's so hard to understand".......
I thought of a way to explain it for individuals who think "visually" (most "artistic types").

Visualize 3 glasses 1/2 full of water. One is labeled ISO, one is Labeled aperture, and the 3rd is labeled shutter speed.
The exposure equals the total quantity of water contained by all three glasses and the exposure (correct exposure) must always remain the same.
You can pour from any glass into another, or from two into the third. When a glass is either full or empty you can no longer add/take from that glass. (i.e. you run out of aperture for a given lens)

Now all you need to know is what number = "more" (fuller).
smaller aperture number = more (fuller)
smaller shutter speed number = more (fuller)
larger ISO number = more (fuller)

If "visualizing" doesn't work for you and you are a more "hands on" type...fill three glasses 1/2 full of water and play with it....

It works for me and I hope it works for you

[candleman]

very good explaination



i initially thought "why not 1/3rd full"
....but you cant use only one parameter for the exposure
IE. pouring it all into one glass..

so this is clearly well thought out

well done

[sk66]

Originally Posted by candleman

very good explaination



i initially thought "why not 1/3rd full"
....but you cant use only one parameter for the exposure
IE. pouring it all into one glass..

so this is clearly well thought out

well done

Thank you, I started to question myself after posting it....
I really didn't think it out that well, but it works for the way I think...
Having an "impression of you", I'm sure you spent more than a few moments considering it and I'm very pleased with your response!

[ZannieGirl49]

Thanks for posting this. I think that you've thought out a great way to describe the exposure triangle. It can be really confusing (it was for me). It wasn't until I took a photography course that the light bulb went on for me. Now I may have to borrow your explanation when I'm asked by friends.

[dcclark]

I like this... It really demonstrates the key idea of how one setting affects the others.

It would be interesting if there were a way to work in the amount of ambient light. For example, the more (total) water there is, the darker the scene? That way, in a dim room, when you push the aperture to "full" (open), there's still a lot of water left over that must still be used.

[sk66]

Originally Posted by dcclark

I like this... It really demonstrates the key idea of how one setting affects the others.

It would be interesting if there were a way to work in the amount of ambient light. For example, the more (total) water there is, the darker the scene? That way, in a dim room, when you push the aperture to "full" (open), there's still a lot of water left over that must still be used.

Except that in a dim room there is more often not enough "water" to get the correct exposure to start with.....

But if we had excess "water" we could implement ND's to absorb it, like a paper towel when a glass is overfilled....

If there was not enough to fill each half full (or equivilent balance) we would need to add more "water" (i.e. flash)

[sk66]

Originally Posted by BryanC

*hic*...I tied, er, I tried using, *hic* , Sco-- Scot-- Scotch instead of water and I keep coming up *hic* way un--underespo--underexplo..underespl...um, dark...*hic*...

But seriously folks...

A very good, clear and simple way of demonstrating the relationship between the three. Nice post!

Thank you, and funny!

[sk66]

Now I'm hoping it benefits someone who is not a "senior member" w/ a decent understanding already.......

[sk66]

Once you get a hold of this basic relationship, then it becomes a question of understandings which setting to favor: Again, fairly basic...and almost every exposure is a compromise..

Shutter speed to isolate/emphasize motion (more/less)
Aperture to isolate/expand area of interest (more/less)
ISO to enable either of the first two....and balance noise...

[jamesev]

Originally Posted by sk66

Once you get a hold of this basic relationship, then it becomes a question of understandings which setting to favor: Again, fairly basic...and almost every exposure is a compromise..

Shutter speed to isolate/emphasize motion (more/less)
Aperture to isolate/expand area of interest (more/less)
ISO to enable either of the first two....and balance noise...

How does white balance and exposure compensation wriggle into this analogy.

Challenge.... commence!