Taking control of your camera
Hello and welcome to my camera course! If you are here you've probably been using your camera on Auto and are starting to get a bit frustrated with some of your photos. Are they sometimes blurred or out of focus? Perhaps the resulting photograph is not what you intended. Or perhaps you just really want to know what all those settings mean on your camera? You've come to the right place. We are going to talk about how taking control of Aperture and Shutter Speed can drastically change the way you take photographs. You'll be amazed at what you can achieve once you understand how to make these two settings work for you.
Lets begin by talking about light, because photography is all about light. A photograph is 'exposed' when you press the button on your camera the shutter opens and light hits your camera's sensor. The resulting photograph is determined by how much light you let into your camera (aperture) and how quickly you do it (shutter speed). It's that simple! We're going to talk through how to make these two settings work for you. Lets get started!
The exposure triangle
The first thing we are going to discuss is how to get a well exposed photo.
A well exposed image is all dependent on how much light you let into your camera.
There are three factors contributing to a well exposed image, and these are often referred to as the exposure triangle.
- Aperture or f-stop (the size of the opening in your lens when you take a picture)
- Shutter speed (how long the shutter remains opens when you take a picture)
- ISO (the sensitivity of your camera’s sensor to light)
A helpful way to explain these elements is to imagine you are standing in a dark room with a window and curtains at one end. Aperture can be compared to the size of the window: A large window will let lots of light into the room. A small window will only let a little light into the room.
Shutter speed is the amount of time the curtains stay open for. Curtains that are opened and closed quickly will only let a little light into the room. Curtains that stay open longer will let a lot of light into the room.
We can stretch the metaphor to imagine you are standing inside the room wearing sunglasses (ISO). Your eyes will be less sensitive to the light if you are wearing glasses and more sensitive to the light without them.
We’ll go through these elements one by one.
This refers to how wide the opening in your lens is.The best way to understand aperture is to think of it as similar to the controls for the pupil of your eye: The wider your pupil opens, the more light is let in.
Aperture is measured in ‘f-stops’.
A lens that is open to its widest aperture (for example f1.4, f2, f2.8, f4) will let a lot of light in. Its narrowest aperture (f16, f22) will only let a little light in.
Moving from one f-stop to the next doubles or halves the size of the opening in your lens (and the amount of light getting through).
Aperture and Depth of Field
When your camera lens is open to its widest aperture, it is letting in a lot of light, creating a shallow depth of field.
This means that only a small part of your photograph will be in focus.
This can be wonderful for creating photos with a blurry background such as in the photo of the bluebells above, this was shot at f2.8, only one of the bluebell plants is in focus.
In the below example, the children are deliberately out of focus because I wanted to draw attention to the unexpected visitor in the background. The focus is on the fox with an aperture of f5.6. A wider aperture (of f2.8 for example) would have blurred the foreground too much and not told the story I wanted, that of my children playing, oblivious to the wild animal in the garden. A narrower aperture (of f16) would have put the children in focus and your eye would not have been drawn to the fox, the subject of this photo.
As you ‘stop down’ and narrow your aperture, you’ll notice that more of your scene appears to be in focus. At f22, virtually your entire scene will be in focus.
The next example was shot at f10, this is because I wanted to get the two adults and two children in focus.
HOT TIP: A shallow depth of field (small f-number = wide open aperture) is good for portrait photos or where you want to isolate your subject from the background. A large depth of field (high f-number = closed down/small aperture) is good for group shots or scenes where you want to include the detail in the background.
2. Shutter Speed
Shutter speed refers to the amount of time the shutter stays open allowing light in to hit your sensor. Your shutter speed determines the amount of motion you are including in your frame. Imagine you are photographing a cycle race. If your shutter speed is set to 1/20, the cyclist will simply be a blur across your frame (this can be a very pleasing effect). A high shutter speed of 1/1000 should freeze the motion allowing you to capture the cyclist in sharp focus.
Have another look at the above photo, do you see each individual water droplet frozen in motion? The shutter speed used in this photo was 1/800, it was enough to capture the individual droplets of the fast moving water sprays.
The next photo shows another example of frozen motion. I managed to capture my daughter in mid-air using an very fast shutter speed of 1/1000.
You may not always want to freeze motion in your photos, sometimes you want motion blur to show movement, to achieve this you’ll need to lower your shutter speed.
You need to be very careful when you do this, have you ever taken a photo on Auto and it comes out unintentionally blurred? This may be because of something called camera shake. When we hold our cameras, no matter how still we think we are, there will inevitably be some movement.
Try hold as still as you can with your camera, look at your hands, do you notice how it moves - ever so slightly - in time with your breathing and your heartbeat? This is called camera shake and it can usually be cancelled out by using a fast shutter speed OR adhering to the simple focal length rule.
So if you're shooting with a 50mm lens, the rule says that you shouldn't pick a shutter speed slower than 1/50 if you want a sharp picture. So you could shoot at 1/80 or 1/100 and be just fine, but don't go to 1/40 or 1/20. If you are shooting at a focal length of 24mm you shouldn't pick a shutter speed slower than 1/24 or if you are at a focal length of 100mm then 1/100 should be your slowest shutter speed.
This is all well and good for sharp photos, but what if you want motion blur? In an ideal situation, you'll have your camera on a tripod so you can get those super slow shutter speeds. However, if you don't have one to hand, you can brace yourself against something or hold your camera on a flat surface to help you get slower shutter speeds.
HOT TIP: A fast shutter speed (1/500 and above) will freeze motion, a slow shutter speed (1/20) will allow you to introduce motion blur into your image
This refers to the sensitivity of your camera’s sensor to light. A low ISO (of 100 - 250) will mean your camera is less sensitive to light, while a high ISO (1000+) will mean your sensor is very sensitive to light and so you will need less light hitting the sensor to properly expose your image.
However there is a trade-off. As the ISO increases so does the digital noise (or film grain) and the dynamic range (the camera’s ability to capture both lights and darks effectively) is negatively affected. Lets look at the two photos below. The one on the left of the couple was taken with an ISO of 250. This is a low ISO, I had lots of light streaming into my camera from the sun so I needed my camera's sensor to be less sensitive to light. I also didn't want a lot of grain on this romantic image. The photo on the right was taken indoors at a birthday party in a room with no windows, so no natural light. It was dark and in order to get a properly exposed photo I had to increase my camera's sensitivity to the light. In order to freeze the motion of the little guy coming down the slide, I needed a shutter speed of at least 1/400. At the widest aperture (f2.8) I needed to ramp my ISO up to 1250 to get a properly exposed photo. If you zoom in you can see how much grain there is in this photo.
ISO numbers start from 100-200 (Base ISO) and double in value. So, the ISO sequence is: 100, 200, 400, 800, 1600, 3200, 6400 and etc. The important thing to understand, is that each step between the numbers effectively doubles the sensitivity of the sensor.
So, an ISO of 200 is two times more sensitive than an ISO of 100, while an ISO of 400 is two times more sensitive than an ISO of 200. This makes an ISO of 400 four times more sensitive to light than an ISO of 100, and an ISO of 1600 sixteen times more sensitive to light than an ISO of 100.
What does it mean when a sensor is sixteen times more sensitive to light? It means that it needs sixteen times less time to capture an image!
Unless they are after a moody feel to their photographs, most photographers try to keep their ISO as low as possible to avoid noise.
When there is plenty of light, you should use the lowest ISO to retain the most amount of detail and to have the highest image quality.
As a general rule when you are outdoors on a bright sunny day you should be able to get a well exposed photo with a fast shutter speed using your camera’s base ISO (the lowest it will go - usually between 100 and 200). At an ISO of 100 there will be almost no grain or digital noise in your photograph.
If you are in shade you may find you need to increase your ISO if you want a fast shutter speed or a narrower aperture.
Likewise, when you are indoors, or taking photos at night when there is not a lot of light around, you will need to bump up your ISO to ensure you get a well exposed photograph.
Putting it all together
So aperture, shutter speed and ISO all work together to allow the right amount of light onto the camera’s sensor to properly expose your image, but how can you tell your image will be properly exposed?
You may prefer a wide aperture and a very fast shutter speed or perhaps you want a narrow aperture and a slower shutter speed. There is more than one way to achieve perfect exposure, the look you are trying to achieve will dictate how you choose your exposure settings. This is where your camera’s meter comes in.
Using your camera’s meter
A good starting point to see whether or not you will have a properly exposed image before you press the shutter is to look at your camera’s meter. This will tell you if your camera thinks you will get a well exposed image with the settings you have chosen.
Where is your meter? You should see it when you look through your camera’s view finder. On the bottom or side of the view finder, you should see a line with some lines through it. This is your camera’s meter. The bigger mark in the centre of the line, is the benchmark you are aiming for when you dial in your settings. When the display blinks on that centre line, the camera’s meter thinks that your settings will result in a properly exposed image.
Which setting should I change? Aperture, Shutter Speed, or ISO?
Think about what you are trying to achieve with your image. The easiest thing to do is to decide which of the following two factors are the most important for your image.
* Is it important to freeze motion? (you’ll need a faster/higher shutter speed)
* Is it important to incorporate deliberate movement / motion blur? (slower shutter speed)
* Do you want a very blurry background, such as in a portrait in the example above? (wider aperture)
* Or is it important to have everything in focus from foreground to background, such as in a landscape in the photo below? (narrow aperture)
* Is it important to have an image with perfect clarity? (you’ll want the lowest ISO you can get)
* Is it important to have an image with more grittiness or are you in a dark room or in a situation with very little light such as during the evening/night-time? (you’ll need a higher ISO)
Lets think about it
If you want to freeze motion (or to incorporate deliberate motion blur in your image) AND you need a very clean image (or gritty digital noise), but aperture doesn’t matter or is less important, then shutter speed and ISO should be your controls, aperture will be your variable.
If you want a blurry background (or everything to be in focus) AND you need a very clean image, but Shutter Speed doesn’t matter or is less important (usually because your subject is unmoving), then aperture and ISO should be your controls, while shutter speed will be your variable.
If you want a very shallow depth of field AND you need to stop motion but your ISO doesn’t matter or is less important, then aperture and shutter speed will be your priorities.
Of course the easiest way to really get to grips with all of this is to practise. So try and take your camera out a few times a week and take photos. You’ll soon be able to change your settings to achieve what you want without even thinking about it.
I hope you have enjoyed today and learned enough to start taking control of your camera. If you spend just 30minutes a week practising what you have learned today, you’ll be amazed at the images you produce!
I’m always here to answer any questions so if you hit a stumbling block or need to know more about the various settings on your camera please do get in touch.
I’d really love to see your work so please do email your images to me at firstname.lastname@example.org
If, like I once did, you find you cannot get enough of taking photographs at every opportunity and you want to learn more, do get in touch. I’d love to help you with taking the next step in your photography,
I look forward to seeing your work! Please do keep in touch.