Camera Usage Photography I COM 241

Single lens reflex camera Uses interchangeable lenses Higher quality image than point and shoot cameras –Greater resolution DSLR –Digital single lens reflex

Exposure Shutter speed + aperture = exposure Basically correct exposure tells camera how much light to let in camera to produce the best possible image

Shutter speed controlled in camera –Shutter opens and closes F-stop controlled by lens –Size of hole that light comes thru Both control how much light let into camera

Shutter Amount of time the shutter is open –Controls amount of light that enters camera Settings are in fractions of a second –So a shutter speed of 4 = 1/4 of a second –A shutter speed of 60 = 1/60 of a second

Each shutter setting is half (or double) the next Typical shutter speeds –1, 2, 4, 8, 15, 30, 60, 125, 250, 500 –Little different on digital cameras

Slow shutter speed – 1/8 to 1/30 of a second Fast shutter speed – 1/125 to1/500 of a second

Bike rider: slow shutter speed during the day (pan shot) Car lights: slow shutter speed at night (time exposure)

Fast shutter speeds during the day

Camera motion Faster shutter speed, less camera movement Longer the focal length of lens, more have to worry about camera movement General rule of thumb –Shutter speed greater than or equal to focal length of lens*

Aperture Opening in the lens thru which light enters camera –Control this by making opening larger or smaller Measured by f-stops –f/1.4, f/2, f/2.8, f/4, f/5.6….f/64

The aperture, or hole in the center of the lens, gets smaller as f number or f-stop increases

Each f-stop is half as fast as the previous one f/1.4 is largest and “ fastest ” –Admits the most light When go from f/2 to f2.8, that ’ s referred to as “ stopping down ”

Shutter closedShutter open

Depth of field/aperture Area of focus is known as depth of field As decrease size of aperture, depth of field increases –More in photo (background and foreground) is in focus

Shallow depth of field, lower f-stop

Greater depth of field, higher f-stop

shot at f/2.8 focus is on boy in middle aperture setting is f/16 focus is on boy in middle

Determinates of depth of field Aperture –Smaller aperture, greater depth of field Lens –Shorter the lens, the greater depth of field Wide angle vs. telephoto Distance from subject –Greater distance from subject, greater depth of field

Aperture / shutter speed Each smaller f-stop cuts amount of light in half Each increase in shutter speed cuts amount of light in half Maintain the same exposure by: –Increasing shutter speed, decreasing f-stop –Or vice versa

500 / f2 250 / f / f 4 60 / f / f8 15 / f11 8 / f16 Correct exposure Open up f- stop, use faster shutter speed Stop down f- stop, use slower shutter speed

Difference is in motion and depth of field –Faster the shutter speed less blurring –Higher the f/stop (f/16) greater the depth of field

1/4 sec, f/16 Small aperture (f/16) produces great depth of field But bird ’ s wings are blurred

1/250 sec, f/2.8 Freezes bird ’ s wings Background is now out of focus

ISO Sensitivity to light Higher ISO, more sensitive to light –Good for low light, fast action –Makes image look more coarse, grainy

Low ISO gives better resolution 100, 200, 400, 800, 1600 Can change on each shot –Digital camera

Determinates of exposure Shutter speed –Faster shutter speed, less light strikes film –Stop action F-stop –Smaller aperture (f/16), less light strikes film –Depth of field ISO Sensitivity to light –800 ISO is more sensitive than 200 ISO –Also looks a little grainer

Light meters Reflected –Meters light reflected from subject –Built into cameras Incident –Measures light falling on subject

What light meter “ sees ” Averages all tones in a scene Converts them to 18 percent gray

High contrast scenes Light background –Causes subject to be underexposed Dark backgrounds –Causes subject to be overexposed

How to compensate Move in closer Meter the palm of your hand For landscapes tilt the camera down