What is the exposure triangle?

What is the exposure triangle? Yes, it can very often be just as confusing as the Bermuda Triangle but I'm going to try and break it down a bit into "real people" terms. So, as the Doctor says, "Allons-y"!

image credit:http://www.bbc.co.uk/programmes/galleries/p0174q9q

So.... the exposure triangle is all about achieving proper exposure (how bright or dark things are in your final image).

There are THREE manual settings (hence the term "triangle") that you can play with to adjust this exposure. They are: shutter speed, aperture, and ISO. All of these three things essentially do the same thing (increase or decrease the brightness of your final image) but each one has it's own special side effects that we have to consider when adjusting them.

image credit: MU Photography

Today, we're going to consider shutter speed. Shutter speed is the setting that determines how long your shutter is open for on your camera and light is allowed to enter and expose the sensor or image. If it's open for longer, more light will be allowed to enter, leading to a brighter image and if it is open for a shorter period of time, then the image will darken (relatively speaking).

image credit: MU Photography

Awesome! So then why don't we just leave it open for a really long time (if we're in a dark room) and then we can get enough light in there to get a fabulously exposed image!? Well... here comes the point where we have to consider side effects. The main "side effect" that a longer shutter speed will create is motion blur (you know, where kids running around are just a blurry mess in your final image or you get those "out-of-focus" shots because the camera moved ever so slightly while we were holding it cause we were trying to do something as simple as breath at the same time as take a picture?).

image credit: MU Photography

The image above of a rambunctious toddler in a fairly well lit room was shot at 1/40 sec. (probably showing up on your camera display as just 40, indicating 1/40th of a second that the shutter is open). You'd probably think, "WOW! 1/40th of a second is super fast so it should freeze the action, right?". Yeah, unfortunately not... when it comes to light (which is what we're dealing with in photography), it's SUPER-FAST! And to freeze it (and the motion of a moving toddler), we need what might sound like some really fast shutter speeds. Soo.... to take care of this "side effect" of shutter speed, and to reduce the motion blur, we just choose a faster speed. In the image below, shot just a few seconds later, the shutter speed was 1/500th of a second.

image credit: MU Photography

Ah yes! Fast enough to catch a Jedi Knight's "Hiya!!"

Now, if all we did was increase the shutter speed and didn't adjust any of the other settings on the camera (you know, at least one of the other two sides of the exposure triangle), then the above image would be quite dark.

image credit: MU Photography

It would be dark because in order to stop the action and take care of all that motion blur, we wouldn't be letting as much light into the camera and then we'd get a dark image. So to compensate for this, all we have to do is change either the aperture or ISO to brighten the image while keeping the shutter speed fast to stop that action.


I hope you follow along this adventure through the EXPOSURE TRIANGLE as the next stop is: APERTURE!

UPDATE:

Click here to visit The Exposure Triangle Part 2: Aperture
Click here to visit The Exposure Triangle Part 3: ISO
Cheers!

lil' mama photog


If you would like to learn more about photography or host your own Yummy Mummy Photo Party, check out our website at www.yummymummyphoto.com



image credit: MU Photography