Photographics 10Photographics 10

Introduction to Digital Introduction to Digital PhotographyPhotography

Mr. ButtingerMr. Buttinger

Holy Cross High SchoolHoly Cross High School

The Digital Process

• The digital camera is one of the most remarkable instances of a shift from traditional technology (mechanical) to new technology (digital) because it is so truly different from its predecessor.

• Conventional cameras – store images on negatives.

• The following images are examples of images which have been created with different films and negatives:

Understanding the Basics

• Let's say you want to take a

picture and e-mail it to a friend. To do this, you need the image to be represented in the language that computers recognize -- bits and bytes.

• Essentially, a digital image is just a long string of 1s and 0s that represent all the tiny colored dots -- or pixels -- that collectively make up the image.

Process of Taking a Digital PhotographHow Canon DSLR Cameras Work - YouTube• 1. By pressing down the shutter button half way, the camera is allowed

to focus on a subject.

• 2. Once the shutter is pressed all the way down, the aperture allows light thru the lens and the image will be recorded upside down onto the CCD. (Charge Coupling Device)

• Canon Camera Shutter and Mirror action in slow motion - YouTube

• 3. The CCD will convert the light and color info. Into 1’s and 0’s (computer language) for each pixel.

• Let's see how a CMOS-Sensor in a Canon DLSR works 2/2 - YouTube

• 4. The camera’s computer will transfer this code of 1’s and 0’s to the LCD screen at the back of the camera and recreate the image on the pixels there. The camera will also save the image’s pixel information as a JPEG in the memory card.

Understanding the Basics

• Both film cameras and digital cameras have a series of lenses that focus light to create an image of a scene.

• It focuses light on to a semiconductor device that records light electronically.

• A computer then breaks this electronic information down into digital data.

• Once the photograph is digital data, the ability to manipulate the image digitally is infinite.

A Filmless Camera

• Instead of film, a digital camera has a sensor that

converts light into electrical charges.

• The image sensor employed by most digital cameras is a charge coupled device (CCD), that converts light into electrons.

• Once the sensor converts the light into electrons, it reads the value (accumulated charge) of each cell in the image.

A Filmless Camera• Pixel:

– A pixel (short for picture element) is one of the many tiny dots that make up the representation of a picture in a computer's memory.

• Resolution:– The amount of detail that the camera can capture is called

the resolution, and it is measured in pixels. The more pixels a camera has, the more detail it can capture and the larger pictures can be without becoming blurry or "grainy.�

A Filmless Camera

• Some typical resolutions include:– 640x480 - This is the low end on most "real" cameras.– 1216x912 - This is a "megapixel".– 1600x1200 � Two megapixels.– 2240x1680 - 4 megapixel, prints up to 16x20 inches.– 4064x2704 - 11.1 megapixels takes pictures at this

resolution. 13.5x9 inch prints with no loss of picture quality.

• How a Digital Camera is Made - YouTube

File Types and Data Storage

• Exchangeable image file format (Exif) is the variety of file formats that can be used to save digital camera’s images.

• RAW & TIFF are used for the highest quality format. (Raw files use up the most memory space.)

• JPEG is used as a space-saving but lower quality format. (Many low-end cameras can deliver only JPEG files.)

BITMAP files are very low quality images reserved usually for only internet purposes.

PHOTOSHOP file (PSD)- image information saved along with Photoshop data (layers, effects, etc…)

Film Types and Data Storage

• Data Storage Devices- A device for storing data. It usually refers to

permanent (non-volatile) storage. (The data will remain stored when power is removed from the device.)

– Here are some typical devices used:• SD card• XD card• Compact Flash

Editing Digital Images

• Digital image editing is the process of altering digital images, (Either digital photographs or other types of digitally represented images.

• Specialized software programs called vector graphics editors or bitmap graphics editors are the primary tools with which a user may manipulate, enhance, and transform images.

Editing Digital Images

• Bitmap images are stored in a computer in the form of a grid of picture elements called pixels.

• These pixels contain the image's color and brightness information. Image editors can change the pixels to enhance the image in many ways.

• Adobe Photoshop is the most common application commercially used for digitally manipulating images.