Chapter Four Digital Photography Foundations (How to use the various settings on your digital camera)

Exposure Correct exposure depends on: Amount of light hits the sensor (aperture) Exposure time (shutter) Sensitivity of the sensor (ISO) Most digital cameras have good built-in exposure meters to help set the correct combinations of the above.

Aperture Eg. f2, f2.8, f4, f5.6, f8, f11, f16, f22, etc. f-stop = Focal length / diameter of aperture The bigger the aperture, the more light passing through

Depth of field Aperture affects depth of field Tutorials on depth of field: http://smad.jmu.edu/dof/ www.photoxels.com/tutorial_dof.html

Shutter speed 1/1000, 1/500, 1/250, 1/125, 1/60, 1/30, … Longer exposure allows more light to hit the sensor.

Reciprocity Increasing the shutter speed (freezes movement) can be compensated by widening the aperture (less depth of field). Similarly, decreasing the shutter speed (longer exposure) can be compensated by reducing the aperture (more depth of field).

Full Auto Mode Fully automatic Evaluates lighting Select ISO, white balance, aperture, shutter speed, flash, etc.

Program (P) Mode Similar to Auto mode Allow setting ISO, WB, exposure compensation Allow choosing aperture-shutter reciprocal combinations.

Program Exposure Canon Powershot G6 Very similar to AUTO exposure but you have access to all the normal manual controls, can set the ISO, exposure compensation, use AE lock, bracketing etc. The G6 has program shift, activate shift by pressing the * (AE/FE-Lock) button, then turn the main dial to select from various equivalent exposures. Example (pressing * metered 1/50 sec, F4.0):  • 1/30 sec, F4.5 (turn left)  • 1/40 sec, F4.0 (turn left)  • 1/50 sec, F4.0 (metered)  • 1/60 sec, F3.5 (turn right)  • 1/80 sec, F3.2 (turn right)

Aperture Priority (A) Mode Preset aperture (by you) Camera adjusts shutter speed based on lighting Give better control to depth of field (wider aperture for less DOF, and vice-versa). Tip: for portraits, you may set a wider aperture to “blur” the subject’s background Tip: for landscape, you may set a smaller aperture to make the whole scene clear

Shutter Priority (S/T) Mode Preset shutter speed (by you) Camera adjusts the aperture based on lighting Tip: fast shutter speed for capturing motion, also avoid “motion blur” due to hand shake Tip: slow shutter for “creative” blur

Manual (M) Mode You may set any combination of aperture and shutter speed and other settings (e.g. ISO). Useful for night and studio photography

Scene Modes Portrait Night portrait Landscape “blur the background” through large aperture and center-weighted metering Night portrait Slow shutter speed to “see enough light” of the background and flash for the foreground subject Landscape Small aperture for deep depth of field More sharpening, contrast, and saturation

Scene Modes (cont.) Night Landscape Beach/Snow and Backlight Slow shutter speed, no flash Beach/Snow and Backlight Compensate for overly bright reflections and backgrounds Close-Up/Macro Longest zoom and fast enough shutter speed (to avoid “hand shake” blur)

Scene Modes (cont.) Sports Black and White/Monochrome Other modes Relatively fast shutter speed to freeze actions Continuous shooting Black and White/Monochrome Capture grayscale images Other modes E.g. fireworks, pets, food

Metadata (EXIF) Records of exposure settings (e.g. ISO, aperture, shutter speed, etc.) Accessible through software

Depth of Field in Compact Digital Cameras Deeper depth of field is achieved by: Smaller aperture Shorter focal length Greater subject distance Compact digital cameras tend to have smaller image sensors and lenses with shorter focal lengths Hence, they tend to give deeper depths of field than compact film cameras.