Understanding ISO, Shutter Speed and Aperture. It is difficult to take good pictures without having a solid understanding of ISO, Shutter Speed and Aperture – the Three Kings of Photography, also known as the “Exposure Triangle”. While most new DSLRs have “Auto” modes that automatically pick the right shutter speed, aperture and even ISO for your exposure, using an Auto mode puts limits on what you can achieve with your camera. In many cases, the camera has to guess what the right exposure should be by evaluating the amount of light that passes through the lens. Thoroughly understanding how ISO, shutter speed and aperture work together allows photographers to fully take charge of the situation by manually controlling the camera. Knowing how to adjust the settings of the camera when needed, helps to get the best out of your camera and push it to its limits to take great photographs.
BobGilchrist 2 months ago. Good start but this will confuse the uninitiated. It is also a missed opportunity to show the relationship in exposure between the aperture. Locate the button, wheel, or dial on your camera or lens that controls the aperture. If you’re using an older camera and lens, the aperture control is a ring that. What is the relationship between aperture, shutter speed and ISO in photography? Learn from this short, comprehensive camera tutorial. Applicable to both.
What settings do I need to change to create a motion blur effect? Turn off Auto ISO and set your ISO to the lowest number. If the shutter speed is too fast and you.
The Exposure Triangle Explained. Creating a harmonious exposure using the aperture, shutter speed and ISO is a juggling act. As soon as you make a decision about one. What are Shutter Speed, Aperture and ISO? © 2006 Ken Rockwell.com.
Let’s quickly review a summary of the Exposure Triangle as a refresher: ISO – the level of sensitivity of your camera to available light. It is typically measured in numbers, a lower number representing lower sensitivity to available light, while higher numbers mean more sensitivity. More sensitivity comes at the cost though, as the ISO increases, so does the grain/noise in the images.
- Shutter Speed. The shutter is a small “curtain” in the camera that quickly rolls over the image sensor (the digital version of film) and allows light to shine.
- What is the relationship between aperture, shutter speed and ISO in photography? Learn about these basic settings on your DSLR camera in this how-to video.
- Learning even just the basics of photography takes a bit of work and one of the more complex ideas is the relationship between ISO, aperture, and shutter speed.
Examples of ISO: 1. Shutter Speed – the length of time a camera shutter is open to expose light into the camera sensor. Shutter speeds are typically measured in fractions of a second, when they are under a second. Slow shutter speeds allow more light into the camera sensor and are used for low- light and night photography, while fast shutter speeds help to freeze motion. Examples of shutter speeds: 1/1.
Aperture – a hole within a lens, through which light travels into the camera body. The larger the hole, the more light passes to the camera sensor.
Aperture also controls the depth of field, which is the portion of a scene that appears to be sharp. If the aperture is very small, the depth of field is large, while if the aperture is large, the depth of field is small. In photography, aperture is typically expressed in “f” numbers (also known as “focal ratio”, since the f- number is the ratio of the diameter of the lens aperture to the length of the lens). Examples of f- numbers are: f/1. How do the Shutter Speed, Aperture and ISO work together to create an exposure? To have a good understanding about exposure and how shutter speed, aperture and ISO affect it, we need to understand what happens within the camera when a picture is taken. As you point your camera at a subject and press the shutter button, the subject gets into your camera lens in a form of light.
If your subject is well- lit, there is plenty of light that travels into the lens, whereas if you are taking a picture in a dim environment, there is not much light that travels into the lens. When the light enters the lens, it passes through various optical elements made of glass, then goes through the lens “Aperture” (a hole inside the lens that can be changed from small to large).
Once the light goes past the lens aperture, it then hits the shutter curtain, which is like a window that is closed at all times, but opens when needed. The shutter then opens in a matter of milliseconds, letting the light hit the camera sensor for a specified amount of time.
This specified amount of time is called “Shutter Speed” and it can be extremely short (up to 1/8. The sensor then gathers the light, based on a pre- defined sensitivity, also known as “ISO”. Then the shutter closes and the light is completely blocked from reaching the camera sensor. To get the image properly exposed, so that it is not too bright or too dark, Shutter Speed, Aperture and ISO need to play together. When lots of light enters the lens (let’s say it is broad daylight with plenty of sunlight), what happens when the lens aperture/hole is very small? Lots of light gets blocked. This means that the camera sensor would need more time to collect the light.
What needs to happen for the sensor to collect the right amount of light? That’s right, the shutter needs to stay open longer. So, with a very small lens aperture, we would need more time, i. Now what would happen if the lens aperture/hole was very big? Obviously, a lot more light would hit the sensor, so we would need a much shorter shutter speed for the image to get properly exposed. If the shutter speed is too low, the sensor would get a lot more light than it needs and the light would start “burning” or “overexposing” the image, just like magnifying glass starts burning paper on a sunny day.
The overexposed area of the image will look very bright or pure white. In contrast, if the shutter speed is way too high, then the sensor is not able to gather enough light and the image would appear “underexposed” or too dark. Let’s do a real- life example. Grab your camera and set your camera mode to “Aperture Priority“.
Set your lens aperture on your camera to the lowest possible number the lens will allow, such as f/1. Set your ISO to 2. Auto ISO” is turned off. Now point your camera at an object that is NOT a light source (for example a picture on the wall) then half- press the shutter button to acquire correct focus and let the camera determine the optimal exposure settings. Do not move your camera and keep pointing at the same subject!
If you look inside the camera viewfinder now or on the back LCD, you should see several numbers. One of the numbers will show your aperture, which should be the same number as what you set your aperture to, then it should show your shutter speed, which should be a number such as “1. ISO. Write down these numbers on a piece of paper and then take a picture. When the picture comes up on the rear LCD of your camera, it should be properly exposed. It might be very blurry, but it should be properly exposed, which means not too bright or too dark.
Let’s say the settings you wrote down are 3. ISO). Now change your camera mode to “Manual Mode“. Manually set your aperture to the same number as you wrote down, which should be the lowest number your camera lens will allow (in our example it is 3.
Then set your shutter speed to the number you wrote down (in our example it is 1. ISO the same – 2. Make sure your lighting conditions in the room stay the same. Point at the same subject and take another picture. Your results should look very similar to the picture you took earlier, except this time, you are manually setting your camera shutter speed, instead of letting your camera make the guess. Now, let’s block the amount of light that is passing through the lens by increasing the aperture and see what happens.
Increase your aperture to a larger number such as “8. Point at the same subject and take another picture. What happened? Your image is too dark or underexposed now! Why did this happen? Because you blocked a portion of the light that hits the sensor and did not change the shutter speed. Because of this, the camera sensor did not have enough time to gather the light and therefore the image is underexposed. Had you decreased the shutter speed to a smaller number, this would not have happened.
Understand the relationship? Now change your aperture back to what it was before (smallest number), but this time, decrease your shutter speed to a much smaller number.
In my example, I will set my shutter speed to 4 (quarter of a second) from 1. Take another picture. Now your image should be overexposed and some parts of the image should appear too bright.
What happened this time? You let your lens pass through all the light it can gather without blocking it, then you let your sensor gather more light then it needs by decreasing the shutter speed.
This is a very basic explanation of how aperture and shutter speed play together. So, when does ISO come into play and what does it do? So far, we kept the ISO at the same number (2. Remember, ISO means sensor sensitivity. Lower numbers mean lower sensitivity, while higher numbers mean higher sensitivity. If you were to change your ISO from 2. In the above example, at aperture of f/3.
ISO 2. 00, if you were to increase the ISO to 4. This means that you could set your shutter speed to 1/2. Try it – set your aperture to the same number you wrote down earlier, multiply your shutter speed by two and set it to that number, then change your ISO to 4. It should look the same as the first image you took earlier.
If you were to increase the ISO to 8. As you can see, increasing ISO from 2.
However, increasing ISO comes at a cost – the higher the ISO, the more noise or grain it will add to the picture. Basically, this is how the Three Kings work together to create an exposure. I highly recommend practicing with your camera more to see the effects of changing aperture, shutter speed and ISO. What camera mode should I be using? As I pointed out in my “Understanding Digital Camera Modes” article, I recommend using “Aperture Priority” mode for beginners (although any other mode works equally well, as long as you know what you are doing). In this mode, you set your lens aperture, while the camera automatically guesses what the right shutter speed should be.
This way, you can control the depth of field in your images by changing the aperture (depth of field also depends on other factors such as camera to subject distance and focal length). There is absolutely nothing wrong with using “Auto” or “Program” modes, especially considering the fact that most modern DSLRs give the photographer pretty good control by allowing to override the shutter speed and aperture in those modes. But most people get lazy and end up using the Auto/Program modes without understanding what happens inside the camera, so I highly recommend to learn how to shoot in all camera modes. If your camera is equipped with an “Auto ISO” feature (known as “ISO Sensitivity Auto Control” on Nikon bodies), you should enable it, so that the camera automatically guesses what the right ISO should be in different lighting conditions.