HOW TO USE A SLR CAMERA

Transcription

1 HOW TO USE A SLR CAMERA THE LENS- lets light into the camera. The shorter the lens the shorter the distance it can focus on and the larger angle it will view. The longer the lens the longer the distance it can focus on and the smaller angle it will view. APERTURE- is the adjustable hole in the lens that lets light

2 There are 2 things to know about Aperture 1) The larger the f-stop number the smaller the aperture and the smaller the amount of light that gets exposed on the film. 2) The smaller the aperture (hole) the more concentrated the image is as it exposes the film and so you get a greater depth of field. DEPTH OF FIELD (or depth of focus) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. This image has a large depth of field. The f-stop number was large The size of the aperture (hole) was small The amount of light that got into the lens was little This image has a shallow depth of field. The f-stop number was small The size of the aperture (hole) was large The amount of light that got into the lens was large

3 HOW TO ADJUST APERTURE To adjust the aperture twist the lens so the f stop number you want matches with the dot. The aperture settings are always on the lens you can tell it is the aperture as the numbers will include a 4, 5.6, 8 and 11 SHUTTER SPEED-Is the speed in which the shutter in your camera opens and shuts to let in light. The faster the shutter speed the less light gets in to expose the film and the image will be darker. The slower the shutter speed the more light gets in to expose the film and the image will be lighter. The bigger the shutter speed number the faster the shutter speed as it represents a fraction of a second ie. A shutter speed of 400 means the shutter opens for 1/400 th of a second.

4 HOW TO ADJUST SHUTTER SPEED SLRs with a LCD screen and DSLRs Analogue SLRs Set camera mode to TV to control the shutter speed Turn the dial to control the shutter speed WHAT DO YOU WANT FROM YOUR PHOTOGRAPH? Is the aperture the priority ie. you want to get a lot of detail from a close object (large aperture) or you want to get a large of depth of field (small aperture) OR Is the shutter speed the priority ie. you want to blur a shot (slow shutter speed) or you want to catch high speed action (fast shutter speed) What is the priority of these photographs? Aperture(big or small) or shutter speed (fast or slow)

5 THE RELATIONSHIP BETWEEN APERTURE, SHUTTER SPEED ISO AND LIGHT Once you know what your priority for the shot is you need to ensure you have the right balance between the light available in the shot, the ISO of you film, the aperture and the shutter speed so that your image will be correctly exposed. Small aperture (hole) = less light. So the shutter speed needs to be slower to let in enough light. Large aperture = more light. So shutter speed needs to be faster to let in enough light Fast shutter speed = less light. So the aperture needs to be larger. Slow shutter speed = more light. So the aperture needs to be smaller ISO- is a measure of film speed/sensitivity or sensor sensitivity In Film photography ISO (or ASA) is the indication of how sensitive a film is to light. It is measured in numbers (100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film to light and the finer the grain in the shots you re taking. In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography 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 cost is noisier or grainier shots. the one on the left is taken at 100 ISO and the one of the right at 3200 ISO 100 ISO is generally accepted as normal and will give you crisp shots (and little noise/grain). When you choose a specific ISO you ll notice that it impacts the aperture and shutter speed needed for a well exposed shot. For example if you bumped your ISO up from 100 to 400 you ll notice that you can shoot at higher shutter speeds and/or smaller apertures as the film is more light sensitive and so needs less light for exposure. Situations where you might need to push ISO to higher settings include: Indoor Sports Events where your subject is moving fast yet you may have limited light available. Concerts also low in light and often no-flash zones Art Galleries, Churches etc- many galleries have rules against using a flash and of course being indoors are not well lit. Birthday Parties blowing out the candles in a dark room can give you a nice moody shot which would be ruined by a bright flash. Increasing the ISO can help capture the scene.

6 LIGHT METER- tells you whether or not your shutter speed and aperture settings are balanced with the ISO you are using and the light present in the environment you are photographing in. When you look through your lens you will see a light meter that will look something like this: If you press and hold your shutter release half way down the arrow on the light meter will signal to you whether you have your settings balanced right to correctly expose your image. What the arrow is telling you If the arrow on the light meter is pointing to any of the numbers with the minus sign on the left your photograph will be under exposed, ie your current camera settings are not going to allow enough light into the lens to expose the image properly and your photograph will be too dark. If the arrow on the light meter is pointing to any of the numbers with the plus sign on the right means your image will be over exposed, ie. too much light will get into the lens and your photograph will be very light. The 0 in the middle of the meter is where you want your arrow to lie as it means the right amount of light will enter the lens and your photograph will be correctly exposed. To get the right exposure, focus on your subject and adjust your shutter speed or your aperture up and down until the arrow is on the 0. MANUAL FOCUS- Your camera may not have autofocus (AF) or you might prefer manual focus (MF) either way this is how you manually focus your camera. Twist the end of you lens until the image is sharp. There are two tools your camera may have to help you to see if your image is sharp and in focus as seen in the diagrams below. i. The split focusing system- When the image matches up on either side of the line in the middle of the circle your image is focused. ii. Crystal focusing system- the image is foucused when the crystals appear clear and sharp.

7 Put it all into practise- Answer the following questions- If you wanted to take photos in a dark environment like a concert would you use a film with a high ISO number like 400 or low ISO number like 100? If you wanted to capture a ballet dancer as she leaps in mid-air would you use a fast or slow shutter speed and would it be a small or big shutter speed number? If you wanted to photograph a flower and have behind it a blurry background what would you do with the aperture, would you set your camera to a high or low fstop number? PHOTO TAKING TASKS!!! Take the following photographs; try to think outside the square when choosing your subject matter. Put the photographs on your blog. 1) Captured motion 2) Blurred motion 3) Large depth of field 4) Shallow depth of field 5) Take a photograph in a dark setting 6) Take a deliberately out of focus shot