1

Aperture (AV mode)

Aperture is a name given to the hole in a lens which controls the depth of field in

photographs. It is controlled by aperture priority (AV) mode which is on your camera and also

in manual mode. The purpose of using aperture mode is to control the depth of field. It’s

useful in landscape photo’s, where a narrow aperture is necessary if objects in the

foreground, background or middle distance are all rendered crisply. It can also be useful in

portrait photography where a wide aperture is used to throw the background out of focus and

make it less distracting.

The lenses are measured in f-numbers. A small f-number means a bigger aperture opening

which reduces the depth of field of an image and let’s more light reach the lens. A high f-

number means a small aperture opening which will increase the depth of field letting less light

into the lens. AV mode let’s you control the aperture and let’s the camera adjust other settings

to get the correct exposure.

Smaller apertures reduce light coming into the camera which will need a longer exposure time

which will want you to use a tripod to keep your camera still.

This shows the range of aperture you can get in a lens.

The first image has been captured with

small f-number which has reduced the

depth of field to the image and has let

more light into the lens. This makes the

background blurry and the object in the

foreground is easily see.

The second image is set on a middle f-

number in-between both the high f-

number and the low f-number. This

makes the background less blurry but

still making the object in the foreground

easily seen. But the aperture is still low

enough to make the background blurry.

The last image has a high f-number

which makes both the fore-ground and

background visible with no blurriness.

This is because the higher f-number is

letting less light in and increases the

depth of field.

Low f-number

Medium f-number

High f-number

Shutter Speed (TV mode)

Shutter Speed measures the length of time the shutter is open to when you press the button

to take a photograph. Shutter mode (S or TV) let’s you control how long the shutter will be

open for. The camera will adjust the other settings to get the right exposure for you.

Shutter Speed is shown in fractions or parts of second. The smaller the number the faster the

shutter opens and closes. As exposures get longer, the shutter speed is measured in whole

seconds.

Slow shutter speed is used to show movement in a photograph by blurring the object. When

the slower shutter speed is used, a longer times passes from the movement the shutter

opens until it closes meaning there is more movement to be recorded by the camera. This

allows more light into the camera which when dark is really good. But when your subject

needs to be still, you will need a tripod to avoid camera shake.

Because there is more light falling on the sensor, the camera will compensate by adjusting

the aperture setting, using one that is small enough to achieve a correct exposure. This will

increase the depth of field in he image.

A faster shutter speed freezes the movement in a photo as it as shorter time passes from the

movement opens until the movement closes. This means less movement is recorded

because there is less time for it be recorded. This makes a sharp image which captures

moments that everyone can’t see with their eyes. Faster shutter speeds need a lot of light to

get the correct exposure.

The image below the difference in shutter speed. The first object has a faster shutter speed

as the moving object is shown without any blurred movement. The third object has a slow

shutter speed has the movement is blurred and the part not moving is seen clearly.

The first image is using a slow shutter

speed as the person moving is blurred

because as longer times passes from the

shutter opening and closing. The non-

moving objects are shown clearly making

sure the moving person is known.

The second image has a medium shutter

speed where the person is less blurry but

is still blurry because the shutter speed

isn’t fast enough to freeze movement.

The third image has a fast shutter image

which is fast enough to capture

movement so it’s froze the moving

person making it look like the person

isn’t moving and is in fact still.

Slow Shutter Speed

Medium Shutter Speed

Fast Shutter Speed

ISO (Film Speed)

The ISO setting changes how sensitive the sensor is to light and is measured in either ISO

and ASA. The ASA number of a film tells you how sensitive the film is to light. A faster film

needs less light to produce an image than a slow one. If you shoot in low light with nothing to

support the camera like a tripod, increasing the ISO speed may be increased to get the image

you need.

The faster an ISO speed get’s, the increase in seeing ‘noise’ on your image. Image noise is

the variation of either brightness or colour information in images made by the sensor of a

digital camera. Image noise is seen as a bad thing as it lowers the quality if the image. Image

noise is more noticeable in the shadows of images and in larger areas of colour such as the

sky. To get a good quality image, a lower ISO speed is required to avoid image noise.

If you crop a small section of an image and enlarge it, you can easily see the noise in the

image and it’s lack of sharpness.

The bottom image shows the difference between an low ISO setting and a High ISO setting. A

lower ISO setting makes the image darker and a higher ISO setting makes the image

brighter.

This image has the biggest ISO setting

as it’s better quality and is showing no

signs of image noise.

The second image has a medium ISO

setting as it doesn’t have as good quality

as the first image does but enough

quality to see the foreground.

The last image has the lowest ISO

setting which has made it blurry and has

given it a loss of sharpness compared to

the first image.

High ISO setting

Medium ISO setting

Low ISO setting

White Balance

White balance helps the camera understand what white is. It has an auto-white balance

setting which will work in most situations. Some situations you may need to change the

setting to adjust the colour in your image. Settings include Cloudy, which in bright daylight will

give your image a warmer tint to it, and fluorescent light which in daylight will give your image

a green tint to it. If the colours don’t show very well you may have to change the setting. But

in some situations you may choose the ‘wrong’ white balance on purpose to change the look

of your image.

Careful adjustments and selections can change the mood of the image quickly. Adding blue

can make your image feel cold and unwelcoming. If you add yellow or orange, these colours

has a the opposite effect to the image and the mood it’s giving off.

The bottom image shows the different settings of White Balance and how it can change your

image from it’s original look.

From the photo’s you can see how different the images look with different settings.

Daylight makes the image look brighter and more natural. Fluorescent gives a blue effect

to the image. Cloudy gives the image a yellow tint. Tungsten makes the image look darker

and more misty.

TungstenDaylight

FluorescentCloudy

Original image

Cropped

Levels

Dodging and burning

Colour adjustments

13

Flatbed Scanner

A flatbed scanner optically scans images, printed text, handwriting and converts them to a

digital image and they can seen on a computer, tablet or mobile. They are commonly used in

offices and have a glass plane and a moving optical sensor with RGB filters.

Advantages of using a scanner:

-Can easily scan a magazine or work

- Can do more than one copy

- Easy to use

Disadvantages of using a scanner:

-Can be expensive to buy

- Some scanners might not scan very well

Webcam

A webcam streams or feeds an image in real time to or through computer to a computer

network. When ‘captured’ the video stream may be saved, viewed or sent to other networks

via the internet or as an email. A webcam is usually connected to a computer by a USB or

can be built into the computer software. They can be a source of security and privacy issues.

Advantages of using a webcam are:

-They’re cheap to buy and easy to use.

-They have good flexibility

Disadvantages of using a webcam are:

-Webcams are seen as a privacy issue as webcams can be remotely activated via spyware.

- Depending on the webcam, the image could not be a good quality and might be slow.

Mobile Phone

A mobile device that has the ability to take images using it’s own camera and take high-

definition video. A camera hone has been available since the early 21st century. They have

fixed focal length lenses and small sensors which can impede on their performance. They can

zoom in and out to get a good photo and an added flash to see things if it’s in the dark.

Different phones have different sensors as a USP (Unique Selling Point). The first camera

phone was sold in 200 in Japan a decade after the first digital camera.

Advantages of using a mobile camera phone are:

-Being able to take easy photo’s without having to carry a camera with you

- A phone can fit in your pocket or easily in your bag.

- The camera is free on the phone so you would just have to pay for the phone.

Disadvantages of using a mobile camera phone are:

-Some phones don’t produce good quality images

- It may be tricky to transfer images on your phone to your computer.