Understanding Exposure, Part 3: Shutter Speed | B&H Explora
The Exposure Triangle is the visual representation of the relationship between three main components of the Exposure: ISO, Shutter Speed. Does anyone know what the shutter speed numbers that have hash marks .. minutes (a single quote mark) and seconds (a double quote mark)? It's a . basics such as the relationship between aperture, shutter speeds, how. Then you need to understand three things — the aperture, the shutter speed, and the ISO. the first thing that comes to mind is its is relationship to Exposure.
The Elements of Exposure As you can see in the graphic above, there are three elements of exposure: These three elements are easiest to think of as an exposure triangle, with each element interacting with the other to result in a good exposure.
Each element of the exposure triangle has a slightly different way of manipulating light, and thereby the quality of the exposure that results: The larger the opening, the more light; the smaller the opening, the less light.
The longer the shutter speed, the more light that results. The shorter the shutter speed, the less light that hits the sensor. The lower the ISO, the less sensitive the sensor is to light.
The higher the ISO, the more sensitive it is.
Understanding Exposure (Shutter speed, Aperture, etc)
That means that you can't always manipulate one setting without having a direct impact on one or both of the other elements of the exposure triangle. For example, let's say that you're taking a portrait outdoors on a sunny day. You've got your camera mounted to a tripod and have dialed in the following settings: In that instance, you have several choices to rectify the situation: You can use a smaller ISO, sayto make the sensor less sensitive to light.
Naturally, if you find that an image is too dark, an opposite action would be necessary, such as using a larger aperture, a slower shutter speed, or a larger ISO.
The Exposure Triangle Explained in Plain English
Understanding Exposure Via a Metaphor Exposure is easier to understand if we describe it in more familiar terms. So, think of the camera as your brain and the lens as your eyes. Just like your eyes can see, but need your brain to record what they see, your lens can see but needs the camera to record what it sees. In this scenario, think of your eyelids like the aperture of a lens: Furthermore, blinking is a good way to think of the shutter speed.
The more you blink, the more that the duration of light is restricted. However, extending the period of time between blinks allows more light to enter your eye. Lastly, think of sunglasses as the ISO for your eyes. Wearing sunglasses makes your eyes less sensitive to light, so it's like using a low ISO like But remove those sunglasses on a bright day, and your eyes will become more sensitive to light, like using a high ISO like All three elements are measured using "stops.
For shutter speed and ISO, those numbers are very straightforward: It's easy to see how stops double or halve the light. ISO is measured in whole numbers like,and so on. Again, this is easy to see given that the numbers are nice and even from one stop to the next.
- Understanding Camera Shooting/Exposure Modes
- Understanding Exposure, Part 3: Shutter Speed
- Shutter Quotes
There are some small bushes 10 feet in front of your camera and some mountians 1 mile in front of your camera. Only the trees will be in focus given the small depth of field. With a smaller aperture you will get a larger depth of field and you may be able to get everything bushes, trees, and mountains in focus.Understanding the Exposure Triangle - Relation Between Aperture, Shutter and ISO
There are charts you can use to look up this information refered to as depth of field calculators or depth of field charts. It is also possible to use a feature on most SLR's called "depth of field preview" to see exactly what your camera will see at your chosen aperture so that you can tell whether the mountains, etc. It is fairly obvious why a small aperture large depth of field can be useful - everything or nearly everything will be in focus.
There are also reasons why a photography might prefer a large aperture and small depth of field. It may be to draw the viewers attention to just one part of the photograph - the viewer will always be drawn to what is in the sharpest focus.
Making compromises - using priority modes: It may also be that the photograher does not particularly care what the aperture is but chooses a large aperture to allow more light so that a faster shutter speed can be used - because what the photography cares most about is freezing some motion. Again, Aperture and Shutter speed, while independent settings, both affect the amount of light so often you want to change both at the same time to keep the amount of light consistent.
Often you must make a compromise. You may desire both a fast shutter speed and a small apeture large depth of field but this may result in a photography that is too dark, so you have to pick which one is more important to you.
This is where the Shutter prioirty and Aperture priority modes of you camera come into play. When you are about to take a picture, there are many things to consider, but one basic choice is which is more important for this shot? Then pick the appropriate mode on your camera. Your camera will display the aperture it has picked for you given your choice of shutter speed.
Your camera's light meter and the choices your camera makes for you: I just said that in Shutter priority mode, you pick that Shutter speed and then your camera will pick the Aperture.
It will be vice-versa for Aperture priority mode.
How does your camera decide what the other setting should be? By default, your camera assumes that you want the overall brightness of the image to be medium gray.
So your camera adjusts the other setting to give you medium gray. Pretend it's a black and white photograph, even if you are shooting in color. For example, your scene has a barn which is maroon [on the dark side], some grass [which is medium], and some blue sky [on the light side]. Overall this scene is naturally pretty close to medium gray. Now in some cases you may not want the overall brightness to be medium gray.
For a winter scene with snow the overall brightness should generally be very light gray almost white if you want your photograph to look natural.