Basic Photography Notes

Basic Photography Notes

Exposure Meters

An exposure meter is a device that determines how much light the film should receive to make a correctly exposed print that is neither too dark nor too light. You cannot actually touch the meter but in many cameras you can see what the meter is deciding through the viewfinder. In inexpensive cameras you cannot see what the meter is deciding through the viewfinder. It is best to have a camera that shows both what shutter speed and aperture are being considered as well as has the ability to override the shutter speed and aperture chosen by the meter. In inexpensive cameras the exposure meter is accurate about 60% of the time.
In the most expensive cameras the exposure meter is accurate almost100% of the time.

Shutter Speeds

The shutter is a mechanical shade in the back center of the camera directly in front of the frame of film you are shooting. When the button on the camera to take a picture is pressed this shade opens for a fraction of a second. If the shutter is open for too little time the photograph will be too dark. If the shutter is open for too long the photograph will be too light. Many cameras allow the photographer to choose a shutter speed. The advantage of this type of camera is that by varying the shutter speed the photographer can control how motion will appear in the finished photograph.

1/8000 will stop any motion

1/4000 high enough speed to take pictures while walking

1/2000 will stop most motion

1/1000 will stop bicyclists and runners

1/500 will freeze a person jumping in the air

1/250 will stop some motion

1/125 to avoid camera shake

Speeds that blur motion. Use a tripod for these speeds.

1/60 slight blurring of motion

1/30 very good speed to show a bit of blur when photographing dancers

1/15 the blurring of motion becomes clearly evident

1/8 the blurring motion becomes more pronounced

1/4 the blurring of motion becomes extreme

1/2 high speed motion begins to become invisible

1 medium speed motion begins to become invisible

2 all motion begins to become invisible

4 more motion begins to become invisible

8 motion develops a fog like quality

B this one allows you to keep the shutter open as long as you want

When choosing a shutter speed to control motion, it must also be a shutter speed that correctly exposes the film so that the photograph is neither too light nor too dark.

Aperture

The aperture is a circular opening inside of the lens. It's diameter is varied by a group of metal flower petal like parts. When the button on the camera to take a picture is pressed all of the petals move together to change the diameter of this opening so that it is set to correspond with the light. If it is a very sunny day the meter will set the aperture to a very small circle perhaps the size of the head of an average carpentry nail. If it is a very overcast day the meter will set the aperture to a very large circle perhaps half the size of the diameter of the lens. If the aperture is open too little the photograph will be too dark. If the aperture is open too much the photograph will be too light. Many cameras allow the photographer to choose an aperture. The advantage of this type of camera is that by varying the aperture the photographer can control how much will appear in focus in addition to what is seen in focus through the viewfinder in the finished photograph. Aperture settings are also called f stops. The term "stopping down" refers to setting the aperture to a smaller circle

45 maximum amount of focus

32

22

16

11

8

5.6

4

2.8

2

1.4 minimum amount of focus

This 1:1 relationship between shutter speed and aperture is the most difficult concept to understand of how to use a camera. You will only understand it by trying it over and over again a couple of hundred times. Fortunately most camera meters will let you ignore this concept. However if you plan to use the Zone System method of making photographs you must understand this relationship between shutter speed and aperture.

Cameras that allow no control of shutter speed or aperture choice will make this decision without your assistance. Cameras designed during the 1970s or earlier that allow control of shutter speed and aperture choice generally provide some type of meter indication as to when you have chosen a shutter speed and f stop combination that will also expose the film just the right amount.

Cameras designed during the early 1980s that provide control of shutter speed and aperture choice allow you to choose either the shutter speed or the aperture and then the meter automatically sets the other one. Cameras designed during the late 1980s that provide control of shutter speed and aperture choice allow you to have the meter set so that both the shutter speed and the aperture are set automatically. This is called a programmed setting. Programmed settings are a tremendous asset to both amateur and professional photographers. There are many situations that happen so quickly you don't want to have to think about the proper shutter speed and aperture. The quality of the photograph is in no way inferior to one made with manual settings. It is just a less controlled photograph in terms of motion and what is in focus.

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Paul Light
paul@lightwavephoto.com
http://www.lightwavephoto.com/basphoto2.html
Last revised May 12, 2002
All materials copyright Paul Light 1998-2002 all rights reserved


Basic Photography Notes
	Exposure Meters An exposure meter is a device that determines how much light the film should receive to make a correctly exposed print that is neither too dark nor too light. You cannot actually touch the meter but in many cameras you can see what the meter is deciding through the viewfinder. In inexpensive cameras you cannot see what the meter is deciding through the viewfinder. It is best to have a camera that shows both what shutter speed and aperture are being considered as well as has the ability to override the shutter speed and aperture chosen by the meter. In inexpensive cameras the exposure meter is accurate about 60% of the time. In the most expensive cameras the exposure meter is accurate almost100% of the time. Shutter Speeds The shutter is a mechanical shade in the back center of the camera directly in front of the frame of film you are shooting. When the button on the camera to take a picture is pressed this shade opens for a fraction of a second. If the shutter is open for too little time the photograph will be too dark. If the shutter is open for too long the photograph will be too light. Many cameras allow the photographer to choose a shutter speed. The advantage of this type of camera is that by varying the shutter speed the photographer can control how motion will appear in the finished photograph. 1/8000 will stop any motion 1/4000 high enough speed to take pictures while walking 1/2000 will stop most motion 1/1000 will stop bicyclists and runners 1/500 will freeze a person jumping in the air 1/250 will stop some motion 1/125 to avoid camera shake Speeds that blur motion. Use a tripod for these speeds. 1/60 slight blurring of motion 1/30 very good speed to show a bit of blur when photographing dancers 1/15 the blurring of motion becomes clearly evident 1/8 the blurring motion becomes more pronounced 1/4 the blurring of motion becomes extreme 1/2 high speed motion begins to become invisible 1 medium speed motion begins to become invisible 2 all motion begins to become invisible 4 more motion begins to become invisible 8 motion develops a fog like quality B this one allows you to keep the shutter open as long as you want When choosing a shutter speed to control motion, it must also be a shutter speed that correctly exposes the film so that the photograph is neither too light nor too dark. Aperture The aperture is a circular opening inside of the lens. It's diameter is varied by a group of metal flower petal like parts. When the button on the camera to take a picture is pressed all of the petals move together to change the diameter of this opening so that it is set to correspond with the light. If it is a very sunny day the meter will set the aperture to a very small circle perhaps the size of the head of an average carpentry nail. If it is a very overcast day the meter will set the aperture to a very large circle perhaps half the size of the diameter of the lens. If the aperture is open too little the photograph will be too dark. If the aperture is open too much the photograph will be too light. Many cameras allow the photographer to choose an aperture. The advantage of this type of camera is that by varying the aperture the photographer can control how much will appear in focus in addition to what is seen in focus through the viewfinder in the finished photograph. Aperture settings are also called f stops. The term "stopping down" refers to setting the aperture to a smaller circle 45 maximum amount of focus 32 22 16 11 8 5.6 4 2.8 2 1.4 minimum amount of focus This 1:1 relationship between shutter speed and aperture is the most difficult concept to understand of how to use a camera. You will only understand it by trying it over and over again a couple of hundred times. Fortunately most camera meters will let you ignore this concept. However if you plan to use the Zone System method of making photographs you must understand this relationship between shutter speed and aperture. Cameras that allow no control of shutter speed or aperture choice will make this decision without your assistance. Cameras designed during the 1970s or earlier that allow control of shutter speed and aperture choice generally provide some type of meter indication as to when you have chosen a shutter speed and f stop combination that will also expose the film just the right amount. Cameras designed during the early 1980s that provide control of shutter speed and aperture choice allow you to choose either the shutter speed or the aperture and then the meter automatically sets the other one. Cameras designed during the late 1980s that provide control of shutter speed and aperture choice allow you to have the meter set so that both the shutter speed and the aperture are set automatically. This is called a programmed setting. Programmed settings are a tremendous asset to both amateur and professional photographers. There are many situations that happen so quickly you don't want to have to think about the proper shutter speed and aperture. The quality of the photograph is in no way inferior to one made with manual settings. It is just a less controlled photograph in terms of motion and what is in focus.
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Paul Light paul@lightwavephoto.com http://www.lightwavephoto.com/basphoto2.html Last revised May 12, 2002 All materials copyright Paul Light 1998-2002 all rights reserved