for Digital Photo Academy
Photography is all about light – observing it, manipulating it, capturing it, and presenting it. In fact, the word photography is based on two ancient Greek words that translate literally to “drawing with light.” Learning photography is mostly about how light interacts with your camera and how you control that interaction to record images.
HOW LIGHT INTERACTS WITH A DIGITAL SINGLE LENS REFLEX (DSLR) CAMERA
Using DSLRs as example:
1. Blue Arrow: Light passes through the aperture (a resizable iris) and the lenses which can be adjusted for focus. Light bounces up off the mirror and out of the optical Viewfinder.
2. When shutter button is pressed (red arrows): aperture sets to the desired size, the mirror flips up, and the shutter slides away like a curtain. Light passes through the lens to the sensor. In Live View, this also happens before shutter button is pressed, so sensor can send image to LCD screen on back of camera.
3. Sensor records image digitally on memory card. The size and electronics of the sensor determines resolution and color detail. (Fun Fact: the SLR camera worked identically, except it used film as the sensor.)
4. DSLRs are Interchangeable Lens (ICL) cameras, allowing you to change focal length and aperture sizes with different lenses.
A Mirrorless ICL camera is much the same as a DSLR without the flip-up mirror. A cell phone camera is mirrorless with cheap non-interchangeable lens and small sensor, using software image processing for focus and image enhancement.
IMPORTANT PHOTOGRAPHY CONCEPT: THE EXPOSURE TRIANGLE
DSLR and Mirrorless ICL cameras provide a dizzying array of features. Use the manufacturer’s default settings for most of them until you know more about them (consult your owner’s manual or find tutorials or books). The exception is the three elements of the Exposure Triangle, which form the foundation of photography and which you should learn to control yourself.
Three things affect exposure (the lightness/darkness of an image): shutter speed, aperture, and ISO. They comprise the Exposure Triangle and determine how dark or light the image will be, measured by exposure value (EV). Slow shutter speed, small aperture and small ISO values each produce darker images. The triangle below describes each of these three.
MODE AND EXPOSURE TRIANGLE SETTINGS
Consult your camera manual for instructions on shutter speed, aperture and ISO, allowing you to get darkness/brightness and related image attributes as you want them. Settings to know:
Mode: Use the Mode dial to select M (Manual), S (Shutter Speed Priority), or A (Aperture Priority). Ignore other settings. To start with, select M mode in which you control all three Exposure Triangle elements.
· Shutter Speed Priority. You select a shutter speed and the camera chooses an aperture to yield a 0 EV. Handy for panning shots.
· Aperture Priority. You select the aperture to control depth of field and the camera chooses a shutter speed to yield a 0 EV.
Shutter Speed and Aperture: Usually thumb/finger dials to flip through numerical settings.
ISO control is usually performed via a button on the camera body.
The current settings on your camera for Mode, Exposure Triangle and the resulting Exposure Value are displayed next to the scene in the Viewfinder or in the Live View LCD screen.
Cell Phone Cameras must provide the above functionality through special apps, for example, check out on Android: Bacon Camera, Camera MX, Camera FV-5, CameraZOOM; or on iPhone: VSCO, Camera +2, or ProCamera.
Suggestion: Before you shut off your camera for the day, it is good practice to return settings to “comfortable” values, so you are not surprised when you start up again. For example: Mode M, Shutter Speed 1/30, Aperture f8, ISO 100.
Poor Exposure Triangle settings can yield bad images (as seen next) but can also be used creatively (as in following).
EXPOSURE TRIANGLE “MISTAKES”
USING EXPOSURE TRIANGLE SETTINGS TO GET WHAT YOU WANT