Intro to Photography Week 1Presentation Transcript
What is Photography? Photography (noun) the process of recording images on sensitized material by the action of light, X- rays, etc, and the chemical processing of this material to produce a print, slide, or cine film
How early did photography start? 11th-16th century: The camera obscura projects an image of its surroundings on a screen Consists of a box or room with a hole in one side Light from an external scene passes through the hole and strikes a surface inside where it is reproduced, upside-down, Allows artists to hand trace the images it projected onto paper
Diagram of a Camera Obscura
The First PhotographsNicéphore Niépces earliest surviving photograph of a scene fromnature, circa 1826, "View from the Window at Le Gras," Saint-Loup-de-Varennes (France). Shot with a camera obscura.
"Boulevard du Temple", taken by Louis Daguerre in late 1838 or early1839, was the first-ever photograph of a person. It is an image of a busystreet, but because exposure time was over ten minutes, the city traffic wasmoving too much to appear. The exception is a man in the bottom leftcorner, who stood still getting his boots polished long enough to show up inthe picture.
Robert Cornelius, self-portrait, Oct. or Nov. 1839.The back reads, "The firstlight picture ever taken."This self-portrait is the firstphotographic portrait imageof a human ever produced.
The first permanentcolorphotograph, taken byJames Clerk Maxwellin 1861. Hephotographed atartan ribbon threetimes, throughred, green and bluefilters.
Types of Early Photographs Daguerreotype: 1839 – 1855 Ambrotype: 1854 – 1870 Tintype: 1854 – 1900 Required exposures of several minutes Expensive and each picture was a once- only affair.
Types of Early Photographs
Introducing Negatives A negative image is a total inversion of a positive image, in which light areas appear dark and vice versa In 1841 Henry Fox Talbot invented the negative-to- positive process Made it possible to create multiple copies of the same image
But all the variousprocesses were tediousand photography wasonly for professionals orthe very rich…
Cameras BecomeCommonplace George Eastman started a company called Kodak in the 1880s. In 1884, George Eastman invented film with a base that was flexible, unbreakable, and could be rolled. The constant changing of solid plates was no longer required.
Cameras BecomeCommonplace Eastman placed this flexible, rolled film into a self-contained box camera. The camera had a small single lens with no focusing adjustment. You’d take pictures & send the camera back to the factory to have the film, much like our disposable cameras today. This was the first camera inexpensive enough for the average person to afford.
Modern Day: 35 mm Film Basic film size Photographic film is cut into strips 35 millimeters (about 1 3/8 inches) wide— hence the name. It took until the late 1940s for 35mm film to become cheap enough for most people to afford
Modern Day:Intro to Basic Print Processing Gelatin silver print: 1895 – current Printed using negatives The dominant black-and-white photographic process of the 20th century.
In the Dark –Processing Black & White Film Process the film negatives Negatives are reverse images. Negative is placed in an enlarger that projects the image onto a photo- sensitive paper… … hence the need for it to be dark… paper is sensitive to any light except red light.
In the Dark
In the Dark Paper is exposed to light… The paper is put through a chemical process: Developer – starts chemical process Stop Bath – stops chemical process Fix Bath – “fixes” image onto paper
Photography Gets Colorful In B&W photographic film there is usually one layer of silver salts. Color film uses at least three layers. Dyes, which absorb to the surface of the silver salts, make the crystals sensitive to different colors.
Photography Gets Colorful In the early 1940s, commercially viable color films were brought to the market. These films used the modern technology of dye-coupled colors in which a chemical process connects the three dye layers together to create an apparent color image.
So how does the camera itself work?
What does a camera do? The camera is a device that senses and records an image. The image can be sensed by: photographic film An electronic image sensor The image is recorded on: photographic film digital memory
What does a photographer do? Photographers control the camera and lens to "expose" the light recording material (either film or digital memory) To form/capture an image… …which, after appropriate processing (in the dark room or on your computer), is converted to a usable, printable image. Expose Capture Process
Parts of a Camera Lens Shutter Aperture Mirror Pentaprism Viewfinder Sensor
Parts of a Camera
Exposure Defined The exposure of a photo determines how dark or light a photo will be when it is captured by your cameras sensor. There are three factors that affect the exposure of a photo: lens aperture shutter speed ISO
Lens Aperture Aperture is the size of the hole in the camera lens through which light enters when taking a photo.
Shutter Speed The shutter speed is the length of time that the cameras shutter is open… How long the cameras sensor is exposed to light through the lens.
ISO * With film cameras, the ISO indicates the sensitivity of the film to light With digital cameras, it specifies the light sensitivity setting for the camera. Range from 100 (low sensitivity, bright light) 3200 (high sensitivity, low light) * ISO stands for International Standards Organization, and it is a standardized industry scale for measuring sensitivity to light.
White Balance A camera setting that adjusts for lighting in order to make white objects appear white in photos. Why? Because light cast from different sources is different in color (called temperature). That is to say, light is rarely truly white in nature but our eyes adjusts. Image data acquired by sensors – either film or electronic image sensors – does not match the sensors in the human eye & does not adjust.
White Balance Auto / AWB – Your camera makes its best guess. Daylight/Sunny Cloudy Shade Tungsten – Incandescent lighting such as lights bulbs. Fluorescent Flash
White Balance The left half shows the photo as it came from the digital camera or SOOC. * The right half shows the photo adjusted.* SOOC = ―Straight Out of Camera‖
The Digital Revolution Digital cameras use an electronic image sensor based on light-sensitive electronics called CCD or CMOS. Digital image is stored electronically In 1991, Kodak produced the first digital camera advanced enough to be used successfully by professionals.
Megapixels A pixel is one dot of information in a digital photograph. A megapixel (MP or Mpx) = one million pixel Expresses the number of image sensor elements of digital cameras
Megapixels The higher the number of megapixels a digital camera can record the more information recorded the larger the image the larger the print but also… the larger the file
JPEG * JPEG is a compressed image file format. JPEG images are not limited to a certain amount of color, like GIF images are. Therefore, the JPEG format is best for compressing photographic images. The JPEG format though, due to its compression, does lose some quality. * JPEG =Joint Photographic Experts Group which created the standard.
Point & Shoot vs. DSLR DSLR have removable lenses have a reflex mirror which allows live optical viewing through the lens taking the image. Point & Shoot more compact you are not seeing a ―live‖ image there is no mirror in the camera
Film vs. Digital Convenience Flexibility in editing Cost Archiving So why does film still survive?
AssignmentBring examples of photographsyou find interesting.