In a previous lesson I was taught about the DSLR camera and things that the camera is able to do.
THE DSLR
In the reflex design scheme, light travels through a single lens and a mirror is used to reflect a portion of that light through the view finder. The image is seen through the viewfinder is also the image that is captured by the camera's sensor.
The DSLR uses a rolling shutter to film Moving Images, whereby portions of the image are scanned as opposed to regular film cameras where the shutter spins and exposes a frame at a time.
APERTURE
The aperture is the opening at the rear of the lens that determines how much light travels through the lens and falls on the image sensor. The size of the aperture's opening is measured in f-stops. The f-stops work as inverse values, such that a small f/number corresponds to a larger or wider aperture size, which results in a shallow depth of field. A large f/number results in a smaller or narrower aperture size and therefore a deeper depth of field.
For more light we 'open up' the lens and for less light we 'close up' the lens.
SHUTTER SPEED
Shutter speed, also known as 'exposure time', stands for the length of time a camera shutter is open to expose light into the camera sensor. If the shutter speed is fast, it lets less light in and it can help to freeze action. If the shutter speed is slow, it allows more light in and can create an effect called 'motion blur'.
ISO
ISO was the indication of how sensitive a film was to light. It was measured in numbers (100, 200, 400, 800 etc.) The lower the number the lower the sensitivity of the film and the finer the grain in the shots you're taking and visa versa.
In Digital Photography ISO, the lower the number the less sensitivity your camera is to light and the finer the grain. Higher ISO settings are generally used in darker situations to get faster shutter speeds, resulting in noisier shots.
100 ISO is generally accepted as 'normal' and will give you lovely crisp shots (little noise).
EXPOSURE
There are three main ingredients to good exposure:
- Aperture
- Shutter Speed
- ISO
If you change just one part of the exposure, it is no longer perfect so you will need to change another point of the exposure an equal but opposite amount to make that triangle and therefore the exposure perfect again.
EDITING EXPOSURE (The Histogram)
In a 'well exposed image' the blacks should be black and the whites should be white. Histograms are a great way of monitoring this. The wave shape is how much pixels that are being recorded and how bright they are. A 'good' exposure should be a mixture of lows, mids and highs with nothing bunching at either end unless completely necessary for the picture.
DEPTH OF FIELD
Depth of Field (DOF) is the front-to-back zone of a photograph in which the image is razor sharp. As soon as an object (person, thing) falls out of this range, it begins to lose focus at an accelerating degree.
Two ways to describe the qualities of depth of field - shallow DOF or deep DOF. Shallow is when the included focus range is very narrow, a few inches to several feet. Deep is when the included range is a couple of yards to infinity. DOF is determined by three factors - aperture size, distance from the lens and the focal length of the lens.
CAMERA RIG
To be in conjunction with the DSLR for three reasons:
- To keep the image steady whilst being handheld
- To allow for focus pulling
- To prevent lens flare
