Fundamentals of Digital Photography• Brief History • Camera Formats • Comparing Specifications • File Types: JPG vs RAW, Raster VS Vector • Pixels and Resolution • Colour Systems • Bit Depth • File Size

A Brief History of Photography

Brief History of Photography• Camera Obscura - as early as 400 BC

Brief History of Photography• Camera Obscura - Abelardo Morell

Brief History of Photography• Approximately 1826: Nicéphore Niépce invented

heliography (sun writing)

View from the Window at Le Gras

Brief History of Photography• 1839: announced the invention of the

daguerreotype - Louis Daguerre

Boulevard du Temple

Brief History of Photography• 1839: Henry Fox Talbot’s “photogenic drawing” • 1841: Calotype negative

Edinburgh Ale: James Ballantine, Dr George Bell and David Octavius Hill by

Hill & Adamson, ca. 1844

salt prints

Brief History of Photography• 1969: George Smith and Willard Boyle of Bell

Laboratories developed the CCD

Brief History of Photography• 1973: Fairchild Imaging

produced the first commercial CCD imager. 10,000 pixel sensor

• (100 x 100 pixels)

Brief History of Photography• 1975: Eastman Kodak engineer Steven Sasson

patented a prototype digital camera

Brief History of Photography• 1975: Bryce Bayer invented the Bayer Color Filter Array

that enabled a single CCD or CMOS image sensor to capture colour images.

Brief History of Photography• 1981: Sony Electronics introduced the Mavica

(Magnetic Video Camera)

Brief History of Photography• 1986: Kodak introduced a 1.4 megapixel sensor

Brief History of Photography• 1988: Digital Darkroom was released • 1988: first JPEG and MPEG standards were set

Brief History of Photography• 1990: Adobe release Photoshop 1.0

• 1990: Kodak released the first professional digital camera system Kodak DCS100

Brief History of Photography• 1994: SanDisk and Kodak released the first

CompactFlash Memory Card

Brief History of Photography• 1995: Canon and Kodak jointly released the EOS DCS

series of digital cameras intended for professional use.

Camera Formats

Camera Formats35mm – “point and shoot”, SLR, Full Frame SLR

Image sensor sizes

Camera Formats• Medium format: 645, 6x6, 6x7 film sizes

Camera Formats• Large Format: 4x5 and 8x10 film sizes

Camera Formats• Large Format: 4x5 and 8x10 film sizes

Core Concepts of Digital Imaging

RasterBitmap (Raster): A file format for digital images that treats the image an array of pixels. (Photoshop)

Pros: rich detail, precise shading, precise editing

Cons: blurry when enlarged (so needs to be created for a specific purpose), large file size

File Formats: PSD, JPG, PDF, TIFF, GIF, PNG,

VectorVector: Images created by mathematical shapes, lines, and curves rather than pixels. (Illustrator)

Pros: infinitely scalable, smaller file size, editable (never “flattened” like a photoshop file)

Cons: limited details, limited effects

File Formats: AI, EPS, PDF, SVG

Vector

Raster

What is a Pixel?

What is a Pixel?

• Short for Picture Element, the smallest element on a computer display or in a digital image.

• One square of color contained in a raster file (photo). It is similar to grain in a photo. Each pixel stores colour information for your image. It will usually store it in either 3 components, known as RGB (Red, Green, Blue), or 4 components, known as CMYK (Cyan, Magenta, Yellow, blacK).

• Arranged in a regular 2-dimensional grid: rows and columns. Monitors divide the screen into thousands (or millions) of pixels. The pixels are so close together that they appear connected.

What is Resolution? • Image Resolution describes the detail contained in an image.

• Pixel Resolution: Total pixel count of a digital image is just one determining factor but generally, the higher the pixel count the higher the resolution.

• Measured in Megapixels, width x height of an image measured in pixels, PPI, DPI and LPI.

• Good quality = continuous tone and no obvious squares of color.

Digital Camera Resolution • Charge Coupled Device (CCD) and Complimentary Metal Oxide

Semiconductor (CMOS)

• Megapixel = overall number of pixels on sensor (CCD or CMOS)

• Not all of the pixels on the chip are used.

Computer Screens & Pixel Resolution:

• Pixel resolution / screen resolution: is the number of distinct pixels in each dimension that can be displayed. ie:1680 x 1050

• Spacial resolution: The measure of how closely lines can be resolved in an image is called spatial resolution. For practical purposes the clarity of the image is decided by its spatial resolution, not the number of pixels in an image. In effect, spatial resolution refers to the number of independent pixel values per unit length.

• 72 ppi for screen or 300 dpi for a print

Spatial Resolution: PPI & DPI

• The more pixels you force to squish into an inch, the smaller pixels have to make themselves, therefore, the higher the PPI count of that image.

300 ppi 100 ppi 72 ppi

Computer Screens & Pixel Resolution: • Standard definition TV (DVD, mini DV):

• 480 progressive or 480 interlaced – 720 x 480 pixels

• High definition TV (HD):

• 720p –1280 x 720 pixels

• 1080 i or 1080p –1920 x 1080 pixels

• Ultra-high-definition TV:

• 2160p commonly called 4K – 3840 × 2160

• 4320p commonly called 8K – 7680 × 4320

Resolution in Photoshop:Image menu > Image Size

Resolution in Photoshop:a little math…

• If we know that we want to print a 4x6 inch image at 300 PPI, then we can figure out how many pixels are in that image:

4” x 300 pixels = 1200 pixels 6” x 300 pixels = 1800 pixels 1200 x 1800 = 2 160 000 pixels in the image or 2MP

4” or 1200px

6” or 1800px

Resolution in Photoshop:a little math…

8”x10” image printed at 300 dpi = 2400px x 3000px = 20.6MB

Printing Resolutions The problem with printing is that most printing devices cannot reproduce exactly what we see on screen.

On screen, a pixel can be any one of a million colours but a printer only has a few colours of ink.

A printer needs to print several dots of ink beside each other to simulate the millions of colours we see onscreen, therefore, one dot is not = to one pixel onscreen.

How many different types of printers are on the market today?

Ink jet / Bubble Jet

Laser

Dye-Sublimation

Off-set printing press

Inkjet printers• Tone and colour are created by dropping liquid ink onto the paper in dithered dots.

• Dithering: the use of scattered dots, somewhat randomized instead of ordered halftone grids, which looks smoother on low resolution devices.

• The closer the dots are to each other the darker they appear.

• Smaller dots = smooth, continuous looking tone in a photo (higher quality and higher resolution).

• 240 dpi to 360 dpi image resolution for photo ink-jet printers

Laser Printers• Similar to Inkjets except toner instead of ink. Tone and

colour are created by “glueing” toner to paper using static electricity and then heat to “fuse” the powder to the paper.

• Instead of dithering laser’s print in screens (grids of dots)

• Laser printers print at one of three settings: 300 dpi, 600 dpi or 1200 dpi.

Dye-Sublimation Use transparent film that resembles sheets of coloured cellophane stuck together end to end. Embedded in this film are solid dyes corresponding to four basic colours: cyan, magenta, yellow and black.

Dye-subs generally are 300 or 400 dpi therefore you need the same amount of image resolution. 1:1 ratio.

Colour Systems• The way a computer or printer mixes colour to reproduce/

simulate the millions of colours we see.

• Photoshop represents these systems as channels.

Bitmap

Greyscale

RGB

CMYK

Colour SystemsBitmap - black or white pixels

Greyscale - 256 shades of grey

RGB - Additive colour (add the colours to get white)

CMYK - Subtractive colour (subtract the colours to get white)

Bit Depth

Colour Depth or Bit Depth: The number of colours contained in an image or displayed on a computer screen.

Bit = The smallest unit of information in a binary system.

How bits relate to colour

• Bitmap = 2 bits

• 8 bit Grayscale = 8 bits (28) = 256 shades of gray

• 8 bit RGB = 8 bits per channel (224) = 16 million colors

• 16 bit Grayscale = 16 bits (216) = 65 thousand shades of grey

• 16 bit RGB = 16 bits per channel (248) = 281,474,976,710,656!!!

Let’s review:

• Photoshop is a raster based image system (in other words, it’s based on pixels) Illustrator is a vector based system.

• The Resolution of an image is the product of it’s total pixels. (and what’s a pixel again?)

• Photoshop’s Image Size command helps us determine physical size (width and height) compared to the pixel count.

Let’s review:

• The resolution of a printer depends on the print system.

• Dye-subs print at 300-400 dpi.

• Lasers print at 300, 600, or 1200 dpi.

• Ink-jets are hard to figure out because they lay down many colours of ink in a dithered pattern. Basically if your image is 240 - 360 dpi and your printer is set to 1440 or higher you’ll achieve good results.

Let’s review:

• There are 4 basic colour systems:

Bitmap

Greyscale

RGB

CMYK

Let’s review:

• A bit is the smallest unit of information in a binary system

• Photoshop can work with 8bit, 16bit and now 32 bit files.

• The higher the bit depth of an image, the more color it contains.