Art 20743 - Digital Hybrid Lecture 1 Art 20743 - Digital Hybrid Lecture 1

Art 20743 - Digital HybridLecture 1

Art 20743 - Digital HybridLecture 1

It’s all about ART and ALL of the POSSIBILITIES inherent in the medium

of photography.

It’s all about ART and ALL of the POSSIBILITIES inherent in the medium

of photography.

Before we get “technical” ...lets looks at some pictures

Before we get “technical” ...lets looks at some pictures

Joseph Nicéphore Niépce - view from his window at Gras 1826

Unknown Photographer - from a hot air balloon

Frederick Evans - Sea of Steps

Ansel Adams - Moonrise, Hernandez, N.M. 1941

Henri Cartier Bresson - Hole in a wall, Spain

W. Eugene Smith - Minimata, Japan

Bruce Davidson - Harlem

Keith Carter - Bubble Boy

Andreas Serrano - Piss Christ

Patrick Nagatani & Andrée Tracey

Doug & Mike Starn - Mona Lisa

Robert Parke Harrison - The Architect’s Brother

Jerry Uelsmann - Untitled, Colorado

Cameras & the 4 VariablesCameras & the 4 VariablesCameras & the 4 VariablesCameras & the 4 Variables

In its simplest form a camera is a light tight box that lets light in an opening on one side so that it may

strike film, paper or digital media on the other side.

There are a 5 basic camera types. SLR’s, Range Finders, Twin Lens Reflex, View Cameras and Digital cameras.

There are 4 variables involved in properly exposing film or digital media.

Aperture, Shutter Speed, the ISO or “Sensitivity to light”and the Amount of light at the scene are factors that need to be known and must work in concert with one another to attain proper

exposure.

This is true whether you are shooting film or digital pictures.

Apertures...aka...f StopsApertures...aka...f StopsApertures...aka...f StopsApertures...aka...f Stops

Older film cameras often had the aperture or f stop displayed on the lens

On low-end digital cameras it might be difficult to find this information on the camera but it’s generally there (via various functions and menus) and it will be available through your image editing application as well

through the “metadata”.

The standard series of aperture numbers is:f2, f2.8, f4, f5.6, f8, f11, f16, f22

It is likely that you will also see numbers that fall between the standard series. These are not “full” f

stops.

Apertures are formed by overlapping leaves of metal inside your lens that can open and close to control the

volume of light entering the camera

Each aperture is also known as an f Stop.

Each opening lets in either 1/2 as much or twice as much light as the one before it or after it.

The aperture or f Stop also controls how much of the picture appears to be in focus. This concept is known as Depth of Field. Depth of Field is defined as the amount of the picture from foreground to background

that appears to be in acceptable focus.

Large aperture openings like f2 yield “shallow” depth of field while small

aperture openings like f16 yield “large” depth of field.

small f# = small depth of field large f# = large depth of field

Controlling how much of the picture appears to be in focus

is a “creative control”. You determine what you want to draw your viewers attention

to.

This example shows “shallow depth of

field”. A very small plane of acceptable focus runs through the boy in the middle. The boy in front and the man in the rear are

clearly not in focus.

Very large depth of field allows the viewer to see

everything from the foreground to the back ground in

acceptable focus. This is not the way normal human vision and experience work and it may add a great deal of interest to the

image.In this example the place in the image

where the photographer is focusing has not changed from the shallow depth of

field picture....the aperture was changed to a larger f stop number to increase

the area of acceptable focus.

Depth of Field is not divided equally

You should note that Depth of Field is roughly divided 1/3 in front of where you are focused and 2/3 behind where you are

focused

Shutter SpeedsShutter SpeedsShutter SpeedsShutter Speeds

There are two basic shutter types. Neither reveals the entire picture all at once. Leaf shutters are found in Large and Medium format

cameras. They have overlapping metal leaves that open and

close when the shutter button is pushed. Focal Plane shutter sit directly in front of where

light is focused and are usually a curtain of metal or cloth with a slit in it that moves either up and down or

side to side.

Leaf Shutter

Focal Planeshutter

Most digital cameras don’t have a shutter at all. Rather the CCD or CMOS chip is simply turned on and

off for the proscribed amount of time

Shutter Speeds on film cameras used to be found on dials that sat on top of the camera. This dial listed

the standard series of shutter speeds.

The Standard series of shutter speeds is:B, 1 sec., 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125,

1/250, 1/500, 1/1000

Digital cameras do not always make it clear what shutter speeds are available unless you use a “manual”

mode or an “shutter priority” mode.

Like apertures, each shutter speed lets in either 1/2 or 2x as much light as the one before it or after it.

The camera’s “Shutter” controls the duration of light that strikes film or

digital media.

Shutter speeds also control the “apparent motion” of things within the image. This is another creative control that you have access

to.

Subjects that move from side to side tend to show a greater degree of blur at slower shutter speeds. This happens because the points of light forming the image will move across the film plane striking different areas of the film. This is perceived visually as

movement.

Motion that comes directly toward you or away from you will show less blur even at slower shutter speeds

because the light forming the image hits the film in a relatively close area of the film.

“Panning” a shot means to follow it while you are shooting the picture. This renders an image that has a

sharp “subject” but a blurred background.

Once you’ve determined the proper exposure via metering you are not locked into just one exposure. There are equivalent exposures and they will yield a different looking picture but it will have the same amount of

overall exposure.

This is true for digital photography as well

Light, Film, Digital & Light, Film, Digital & Metering for Proper Metering for Proper

ExposureExposure

Light, Film, Digital & Light, Film, Digital & Metering for Proper Metering for Proper

ExposureExposure

The Visible Spectrum

For the purposes of the class we are primarily

concerned with the visible spectrum. That is the part of the electromagnetic

spectrum with wavelengths of light from 400 nanometers to 700 nanometers. These are the colors you see in the

Rainbow.

In the world of films there are specialty films that are sensitive to other parts of the spectrum. X-ray and Infrared are common ones.

The film you are familiar with consists of several layers.

Essentially, it is a piece of plastic coated with a gelatin emulsion which has

a form of silver in it.

This “silver halide” emulsion is sensitive to all parts of the visible

spectrum equally.

Color films are constructed the same way however, they contain 3 layers of silver emulsion which will be bleached and dyed

in the development process.

Film comes in a number of different formats or sizes

They also come in different types and sensitivities

There are advantages and disadvantages to each

Films are rated for their relative sensitivity to light. This designation is known as the ISO Number or Film Speed. The International Standards Organization

is responsible for this standardized rating.

Films that have low numbers are “slower” films but have finer grain

Films that have higher numbers are “faster” films but have more grain

Digital photography has the same system for the purposes of determining exposure. There is also an equivalent visual experience to “grain” in digital

photography

To get correct exposure for film or digital cameras you must properly meter the light at the scene of the

photograph

This involves pointing your camera at the subject, activating the metering system and properly interpreting the results from this act.

Many cameras work well with automated meter settings however, its important to understand there will be

exceptions to this

Exposure for all cameras is determined by a meter calibrated for an 18% gray card

This arrangement tends to works well under most conditions where the scene has a variety of tones or

colors represented.

This arrangement encounters difficulties when the light and tonal ranges are extreme

It is important to understand this concept and how it works so that you may intelligently compensate when you

run into those adverse lighting conditions

These are typically difficult lighting situations

The solution is to NOT meter the extreme tones

It is critical to understand how your camera works!

All Digital imaging is based on what came before it and it is important

to understand the controls that you have available for creative purposes

If you have a “point and shoot” digital camera you need to familiarize yourself with the following modes: Shutter Priority, Aperture Priority, Manual and

Programmed Exposure.