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Aperture (AV mode)Aperture is another name for the hole in the lens of a camera

through which light floods into the camera. The diameter of this hole can be adjusted by using the aperture priority mode, adjusting this controls the depth of field in an image. The depth of field is a term that refers to the range of distance that appears sharp in an image.

Lens aperture sizes are measured in f-numbers or “f-stops”, the lower the f-number the bigger the aperture opening meaning the depth of field is reduced and light intake is increased. Higher f-numbers mean that the aperture opening will be much smaller, increasing the depth of field but decreasing the amount of light able to enter the camera.

The size of the aperture has a direct impact on the depth of field. A large f-number like f/32 will bring all foreground and background objects in focus, while a smaller one like f/1.4 will isolate the foreground and blur the background.

In taking this photograph I set the camera to AV mode and set the aperture to f/16. This is quite a high aperture setting and so the foreground is in focus but the image goes blurry towards the background. As less light is let into the camera the depth f field decreases.

In this image I set the camera to quite a medium aperture of f/8. This makes the depth of field larger and so more of the image from the foreground to background is in focus. This is good for situations where a larger subject in the foreground is desired to be in focus but the background still wants to remain blurred.

When taking this image I set the aperture to f/4 meaning the depth of field was large and so the whole of the image could be in focus, from the foreground to the background. This is good in situations where you want the background to be in focus as well as he foreground, for example if you were photographing someone in front of a famous monument.

f/16

f/8

f/4

Shutter Speed (Tv mode)Shutter speed is the length of time the camera’s shutter is open when taking the photograph. These times are recorded in fractions of a second but are often simplified so 1/125 sec is shown as 125, 1/15 sec as 15 and so on. Speeds of a second or longer are shown as 1”, 2”, and so on. The longer the shutter is open the longer the film or image sensor is exposed to light.The shutter speed can also change the way movement appears in a photograph, a short one freezing fast moving objects and long ones blurring them, often for artistic affect. You must think about your shutter speed in relation to your aperture as these two settings work together and counter act each other. Taking an image with a slow shutter speed and narrow aperture and then one with a fast shutter speed and a wide aperture will get you two photographs of similar brightness. This means if you want a fast shutter speed to capture a running athlete, you must compensate by widening your aperture to let more light in.When shooting with no tripod you must be sure to use a fast enough shutter speed in order to avoid camera shake. If the shutter is open too long it will capture the movement you make while taking the image, even if you thought you were being completely still.

In this photograph I have set the shutter speed to one one-hundredth of a second. This is a very quick shutter speed and means that the motion can be frozen.

In this photograph I have set the shutter speed to one-eighth of a second. This is quite a middle range shutter speed and as you can see doesn’t freeze the motion as in the photo above, but shows some of the motion as blur. This can be done to create artistic affect but can also just be camera shake and in this case I think it was as I was not using a tripod.

This image has been taken with a very slow shutter speed of one third of a second. Because of this slow shutter speed there is a lot of blur and camera shake. This, if planned can add to the quality of the photo and give it good artistic affect, but sometimes it just looks as though the shutter speed hasn’t been correctly set. Using a tripod to hold the camera steady would be a good way to ensure the only blur I am getting is motion blur and not from camera shake.

1/100

1/8

0”3

ISO settingsISO is the sensitivity of the image sensor to available light. This sensor is the most important part of the camera responsible for gathering light and transforming it into an image.ISO is measured in numbers, the lower the number, the lower the sensitivity meaning that if you take a photo in a very bright environment the sensor will not take too much of it in blowing out the image.In a dark situation a high ISO is more suitable and will allow the camera to capture images without the need for a flash. Higher sensitivity does however come at a price, and the higher the ISO the more grain or noise you can see in the image. Grain is variation in brightness and colour of an image and decreases the quality of your photograph.Each camera will have a base ISO which is the lowest ISO number that the sensor can produce the highest image quality without adding noise so optimally you should always try and stick to the base ISO. However in low light situations you may not be able to do so.Typically ISO numbers start from around 100-200 and go up by the power of two so 100, 200, 400, 800, 1600, 3200, 6400 etc. The important thing to take from that and to ensure you understand I that with each jump up in the ISO numbers light sensitivity effectively doubles. This also means that when a sensor is for example four times as sensitive to light it needs four times less time to capture the image, this is where shutter speed comes into effect.

Example

ISO 100 - 1 secondISO 400 – ¼ second

This must be considered to ensure that you can freeze motion and get the quality images you want.

In this photograph I used a very low ISO. In this instance the natural light wasn’t really good enough to use such a low ISO setting and so the image is too dark.

In this photograph I used quite a middle range ISO setting and increased the light sensitivity slightly, but the image is quite dim and not very well illuminated.

In this photograph I used a very high ISO and this illuminated the image very well where the natural light available couldn’t.

100

400

1600

White BalanceWhite balance is the way you can get the colours in your photographs as accurate as possible. Sometimes, if the white balance isn't correctly set, images can come out with an orange, blue or yellow tint to them, and not look like the real thing. Different types of artificial light can cause these different tints, for instance fluorescent lights often give an image a blueish look while tungsten lighting often adds a yellowish tinge to the image. These different tinges are often called “Temperature”.Preset white balances often work well and the auto-setting is usually enough to work out the right white balance for a photograph. Most cameras also have a manual white balance mode where you tell the camera what white looks like so it can determine what the other colours in the image should look like. You do this by taking a photo of a white card specifically made for this purpose, this tells the camera what the colour looks like in the light conditions of the scene and allows the other colours to be collaborated accordingly.

The white balance settings made a difference to the temperature of the images. The first two photographs have a warmer tinge to them, as they have been set as the shade and cloudy settings. These light conditions give a slightly blue look to photographs and so the camera compensate for this by warming the image, hence the yellow/orange warmth.The second two photographs have been taken with the tungsten and florescent settings. These light settings give off a yellow light, especially the tungsten light, so again, the camera compensates by cooling the image. This is why the photographs have a blue tint.The idea is to get the white balance right so you cant see a coloured tint over the image and it just looks accurate, with all the correct colours.

ShadeCloudy

FlorescentTungsten

Original image

Cropped

Levels

Dodging and burning

Colour adjustments (curves)