Elements of Exposure
Exposure refers to the amount of light and the duration of time that light is allowed to expose film or a digital-imaging sensor. Exposure is controlled by f-stop, shutter speed, and film speed/iso
Stop An increment of exposure that doubles or halves the amount of light of an exposure. F-stops, shutter speeds, and film speeds are calculated in stops. - one-stop difference between: - f/8 and f/11-1/60 and 1/125 of a second, - the ISOs 200 and 400.
Aperture Aperture refers to the lens opening through which light passes on its way to the film or digital sensor F-stop A numerical representation of the diameter of a lens aperture. f = focal length of the lens in a fraction. The smaller the f-number, the bigger the aperture and the less depth of field. The bigger the f-number, the smaller the aperture and the greater the depth of field
Aperture Depth of field refers to how much the scene is in focus, both in front of and behind the subject or the point of focus.
Aperture f/1.4 wider = shallow depth of field f/2.0 f/2.8 f/4.0 f/5.6 f/8 f/11 f/16 f/22 smaller = greater depth of field
Aperture
Aperture & Shutter Speed The aperture and shutter-speed combinations shown below allow the same amount of light to enter the camera but result in different images. Smaller apertures extend the zone of sharp focus, and slow shutter speeds show blurred movement.
Aperture Larger f/stop number Stopping down = closing the opening = block more light from entering the camera. Smaller f/stop number Stopping up = opening the aperture = allow more light into the camera.
Aperture Aperture F7 Distance 10 Feet Away Both in focus
Aperture Aperture F7 Distance 5 Feet Away Right Figurine out of focus
Aperture Aperture F7 Distance 2 Feet Away Right Figurine out of focus
Below 50mm Wide Angle Looks like you got Further away MORE DOF Above 50mm Telephoto Looks like you got closer LESS DOF
The further away you are The wider the DOF The Closer you are The more narrow your DOF
1. A- All pictures you took in class today 2. 2 pictures of the same subject: Low F# and High F# 3. 3 Pictures, Choose subject, you move closer to subject same aperture 15 feet away 10 feet away 2 feet away 4. 3 picture, subject and photographer do not move. Same aperture. Zoom out completely Zoom in halfway Zoom in all the way
Depth of Field Shallow depth of field Greater depth of field f/2.8 f/8 larger aperture = smaller # = less depth of field Smaller aperture = larger # = greater depth of field
Depth of Field Shallow depth of field are good for close ups Greater depth of field are good when you want to capture everything
Shutter Speed Shutter speeds the amount of time the mechanical door in a camera or lens opens and closes to allow light to hit the film or digital-imaging sensor. Expressed as fractions of a second or as numbers of seconds Depends on the lighting conditions, the film speed, and the f-stop Shorter duration = less light gets to the film Longer duration = more light
Shutter Speeds 8 sec. Very slow (candle light) (blur action) 4 sec. 2 sec. slow 1 sec. ½ sec. ¼ sec 1/8 sec. 1/15 sec. 1/30 sec. 1/60 sec. 1/125 sec. 1/250 sec. 1/500 sec. fast 1/1000 sec. 1/2000 sec. 1/4000 sec. Very fast (bright outside) (freeze action)
Shutter Speeds
Shutter Speeds L: Hugh in midair on fast shutter speed R: Hugh in midair on slow shutter speed
Shutter Speeds Shorter duration = faster less light gets to the film More frozen /static the subject and action Ex: Freeze a sports action Longer duration = slower More light More blurring and streaking of the subject Ex: Blur a waterfall
Shutter Speeds Fast shutter speed Slow shutter speed
Film Speeds Film speed a number that represents a film s relative sensitivity to light. The lower the number, the less sensitive the film is. The higher the number, the more sensitive it is.
Film Speeds ISO International Standards Organization. It indicates how sensitive the film is the light. Lower numbers = slow film (50, 100, 200) - less sensitive - more light is needed higher numbers = fast film (800, 1600) - less light is needed - more sensitive
Film Speeds (ISOs) 25 50 slow 100 200 400 800 1600 fast 3200
Example Shutter speed @ 1/125 sec., Aperture @f/2.0 I want a greater depth of field & change my aperture to f/4.0 (2 stops down). I will need to change my shutter speed up 2 stops to 1/30 sec. (to compensate for the light loss)
Measuring the light (w/ aperture & shutter speed) ½ sec. @ f/22 @ f/5.6 (4 stops up) ½ sec. @ f/22 1/8 sec. @
Measuring the light (adding ISO) ISO 100: 1/60 sec. @ f/8 Stop down two ISOs to 400 Absorbing light faster (ISO 100 400) Want to keep the same depth of field Need to speed up shutter speed (1/60 sec. 1/250) 2 stops down To compensate for the more sensitive light to film. ISO 400: 1/250 sec. @ f/8
Measuring light 1. ISO 100: 1/125 sec. @ f/5.6 ISO 400: sec. @ f/5.6 2. ISO 100: 1/125 sec. @ f/5.6 ISO 100: sec. @ f/22 3. ISO 800: 1/125 sec. @ f/16 ISO 800: 1/15 sec. @
Exposure Metering Basics Exposure metering using either a handheld meter or a camera s built-in meter to determine the exposure for a given situation or scene Underexposed images little shadow detail, no defined highlights Overexposed images the photo is too bright. Typically colors will look washed out and highlights will often be "blown out" or completely white. - lacking color or detail
Exposure Metering Basics Underexposed Overexposed
Exposure Exposure is determined by the combination of shutter speed and aperture (f-number). If you increase the f-number, you can still achieve optimal exposure by choosing a slower shutter speed. To put it another way, if you lower the f-number, you can still produce a photograph of the same brightness by choosing a faster shutter speed.
Exposure Metering Basics Spot Metering when the meter in a camera reads from a small area in the center of the viewfinder by reading light within a narrow angle, usually 1% - 3.5% of the image area. 1. Decide the aperture setting 2. Spot meter a neutral grey 3. Set the shutter speed according to the camera s meter
Exposure Metering Basics 1. Decide the aperture setting 2. Spot meter a neutral grey 3. Set the shutter speed according to the camera s meter
How to hold a camera Cup, don t grip the lens
Elbow tuck
Making a stance
Right-angled stance