Digital Art 2016-17Camera Basics

Stop – a photographic unit of measurement pertaining to either shutter speed, film/sensor speed or aperture (f-stop). The numbers are 1⁄2 or double in relation to one another.

Aperture – The adjustable opening in the lens that light travels through to the camera body. F-stops – The various settings of the aperture.

Depth of Field (DOF) - The area in focus from foreground to background. Depth of field is controlled primarily by aperture but also can be influenced by your lens’ focal length and your distance from the subject.

Focal Length - The distance between the center of a lens or curved mirror and the camera sensor or film. Focal length controls the amount of the scene shown (the angle of view) and the size of objects (their magnification).

Shutter – The window or door in the camera body that opens when you push the shutter button allowing light to strike the film or sensor.

Traditional, full f-stops on camera lenses:

f-1.4, f-2, f-2.8, f-4, f-5.6, f-8, f-11, f-16, f-22, f-32, f-45, f-64 Large opening « -------------------------------- » Small opening

An f-stop indicates the size the aperture is set at. The number is relative to the length of the lens. F-stops are actually fractions. F-4 is actually 1⁄4, meaning the diameter of the aperture measures 1/4 the length of the lens. Example: A 50mm lens set at f-4 has an aperture measuring 12.5mm in diameter. A 50mm lens set at f-2 has an aperture measuring 25mm. 25mm = 1⁄2 of 50mm, therefore an aperture measuring 25mm in diameter on a 50mm length lens is referred to as f-2. Hopefully this will explain why a small number like f-4 is actually bigger opening in the lens than f-8.

Note: Your camera will probably not have all of these f-stops. Your camera lens will most likely only feature a portion of the list above. Newer cameras often feature partial or half stops such as 3.5, 9.5 or 13.5. Zoom lenses ranging from wide to telephoto have a smaller range of f-stops than a lens with one fixed length.

Traditional shutter speeds that are one stop apart: 1, 2, 4, 8, 15, 30, 60, 125, 250, 500, 1000.

Note: The above numbers are actually fractions of a second. So they really represent 1/1, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, and 1/1000 of a second. Therefore 1/1 means 1 full second and 1/1000 means, “Man that was quick!”

Again, like the f-stops, a smaller number is actually more than a larger number since 8 refers to

1/8th

of a second and 60 refers to 1/60th

of a second.

Traditional film speeds: 50, 100, 200, 400, 800, 1600, and 3200

The higher number film speed indicates a faster film. 200-speed film captures images faster than 100 or 50 speed film. 200-speed film is twice as fast as 100-speed film. Therefore it is one stop faster. 400- speed is two stops faster than 100 speed film.

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Film/sensor speed (ISO), shutter speed, aperture setting (f-stop), and the amount of light falling on the subject work together to form your images. These make up the 4 factors that control exposure.

Digital Tips:

Photograph using the RAW file format. Photograph using as low of an ISO as you can. Push the histogram to the right, but without overexposing. Set your file numbering to continuous. Color space: Adobe RGB (not sRGB) Normal LCD brightness Photograph in manual mode to have the most control over your image capture. Format the memory card instead of just deleting the files. Make sure the date and time is correct on the camera. A short review time will extend the life of the battery.

In-Class Assignment Week of Tuesday, August 30th, 2016 Bracket Film, Shutter Speed & Aperture

1. Plan on exposing 3 images (scenes) in groups of three. Expose (bracket) each three-frame grouping of the same image at one stop under-exposed (N-1), normal-exposure (N), and one stop over-exposed (N +1). Use your camera’s light meter to determine camera settings for a normal exposure. Increase and decrease exposure by one stop above and below normal by using either the shutter or aperture (not both). If you have completed the assignment correctly you should end up with 3 sets of brackets (each set should contain the exact same scene from the same vantage point on all three frames). This makes 9 photographs total. Take notes. If you have metered correctly (and assuming your meter is working properly) the middle frame of each bracketed set will be optimally exposed, or very close. If not, we will need to make some adjustments.

2.

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2. You will then make numerous exposures using all the shutter speeds and f-stops on your camera. You may need to set your camera on a tripod or some other stable surface. Set the camera to shutter priority (Tv) and make exposures using every possible shutter speed while repeatedly photographing an object or person moving across the picture plane. You might photograph divers or gymnasts. Your images will range from freezing the subject’s action to having a blurry subject progressing across the photograph.

3. Then switch to the camera’s aperture priority (Av) to make exposures using every possible f-stop on the camera while repeatedly photographing a series of objects that recede into space. Your images will range from only one or two objects being in focus to having the entire scene sharp.

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