Please Support - Ride for the child

This week I bought a new camera, a Canon 1100D. I know absolutely nothing about photography so I decided to do a bit of basic learning to enable me to get practicing.

The exposure triangle

What is it?

This is the intersection of the following three elements that an image’s exposure is worked out.

  • ISO – the measure of a digital camera sensor’s sensitivity to light
  • Aperture – the size of the opening in the lens when a picture is taken
  • Shutter speed – the amount of time the shutter is open

Shutter speed

What is it?

Shutter speed is the amount of time the shutter is open.

It is measure in fragments of seconds eg 1/2500 is much faster than 1/10. A standard shutter speed are 1/60th or faster, anything slower is difficult to use with camera shake (camera movement making it blur). If you use a shutter speed under 1/60 then it’s recommended that you use a tripod to steady the camera.

You should always consider if anything in your shot will be moving when choosing your shutter speed. If it’s moving you have two choices. Either freeze the moment (fast shutter speed), or letting the moving object look blurry (slow shutter).

Shutter speeds should be thought about alongside aperture and ISO. Changing shutter speeds means that you’ll need to change one or both of the other elements to compensate for it.

For example if you speed up your shutter speed one stop (for example from 1/125th to 1/250th) you’re effectively letting half as much light into your camera. To compensate for this you’ll probably need to increase your aperture one stop (for example from f16 to f11). The other alternative would be to choose a faster ISO rating (you might want to move from ISO 100 to ISO 400 for example).


What is it?

Aperture is ‘the size of the opening in the lens when a picture is taken.’

This means that the larger the hole the more more light that gets in – the smaller the hole the less light. Moving from one f-stop to another either halves or doubles the amount of opening in the lens.


Keep in mind that a change in shutter speed from one stop to the next doubles or halves the amount of light that gets in also – this means if you increase one and decrease the other you let the same amount of light in – very handy to keep in mind).

Depth of field

The most noticeable change from adjusting the aperture will be the depth of field that a shot has.  The Depth of Field (DOF) is that amount of your shot that will be in focus.

A large DOF means that most of your image will be in focus. A small DOF means  that only part of the image will be in focus and the rest will be blurred.

Aperture has a big impact upon depth of field. Large aperture (remember it’s a smaller number) will decrease depth of field while small aperture (larger numbers) will give you larger depth of field.

In conclusion

A large aperture eg 1.8 concentrates on something and makes the rest of the picture blurred. A small aperture eg 22 focuses on a larger image leaving none blurred.


What is it?

ISO measures the sensitivity of the image sensor. The lower the number the less sensitive your camera is to light and the finer the grain.

Higher ISO settings are generally used in darker situations to get faster shutter speeds. For example an indoor sports event when you want to freeze the action in lower light. However the higher the ISO you choose the noisier shots you will get.

100 ISO is generally accepted as ‘normal’ and will give you lovely crisp shots (little noise/grain).

How you choose it?

When choosing the ISO setting I generally ask myself the following four questions:

  • Light – Is the subject well lit?
  • Grain – Do I want a grainy shot or one without noise?
  • Tripod – Am I using a tripod?
  • Moving Subject – Is my subject moving or stationary?

If there is plenty of light, I want little grain, I’m using a tripod and my subject is stationary I will generally use a pretty low ISO rating.

If it’s dark, I purposely want grain, I don’t have a tripod and/or my subject is moving I might consider increasing the ISO as it will enable me to shoot with a faster shutter speed and still expose the shot well.

Situations where you might want to push ISO to higher settings include indoor sports, concerts, art galleries (might have a rule against flashes), blowing a birthday cake out in the dark


AV – Aperature priority mode

If you would like to choose your aperture, allowing you to choose your depth of field, aperture priority is a good choice. Aperture priority will allow you to set the aperture, again with your dials, and will choose the best matching shutter speed for you. This will allow you to change your depth of field manually, so you can increase or decrease the focus on your background details, as well as let you bring both into focus if you would like. To increase your depth of field and allow more things to be in focus, make sure you change your aperture to a larger number, this creates a smaller aperture hole. To decrease your depth of field, and cause some objects to be out of focus, make sure to set your aperture to a smaller number, this creates a larger aperture hole.

TV – Shutter priority mode

Shutter priority is the exact opposite of aperture priority, it allows you to select if you want a fast or slow shutter speed while the camera chooses the best aperture for the shot. You are able to use this for stop-action shots as well as blur motion images. If you slow down the shutter speed on a moving subject you can blur the action, illustrating the motion in the photograph. Both the aperture and shutter priority modes allow you to get out of the box with your images and experiment with what you can do with your camera.

P – Program mode

If you would like to choose some of the settings, but not all of them, use the Program Mode. While on the P mode the camera chooses the correct shutter speed and aperture for your chosen frame. This mode is good for when you want to do something creative with your images and get different variations of light and depth of field, but still want the camera to help you with the settings. You still have control of the flash and focus in this mode. You can keep the correct exposure and set a lower aperture or shutter speed by toggling the aperture or shutter speed dials while keeping the shutter button half clicked. Make sure that if your shutter speed gets below 1/250, displayed as 250, to use a tripod (personal opinion, some people may want to use a tripod at higher higher speeds as well).

M – Manual

The manual setting is one of the ‘creative mode’ settings on a canon, where you can choose your shutter speed and your aperture to create any match of the two that you desire. You will be able to choose if you want the image to be a little darker, a little lighter, or even a slower shutter speed, and you can interchange the two as needed. In this mode you will see the aperture and shutter speed numbers through the viewfinder called the exposure level indicator. You can use dials on your digital SLR to change these settings. In this mode you can have auto focus turned on or off, and you can choose which selectors to use for your focus if automatic focus is turned on. This setting is recommended for more experienced photographers. If you are just getting started with your camera, and you want to use this mode, start off experimenting with the settings and seeing what works, your goal is the get the smaller bars on the indicator as close to zero as your are able to, as zero is the “correct” exposure. Use of this mode may require a tripod and flash.

A-DEP – Automatic Depth of field mode.

The automatic depth of field mode will set the aperture for you. It will choose a higher aperture number, which is a smaller aperture hole, to allow the foreground and background to be in an acceptable focus.