Lesson 4: 15.3.2010 – Image Basics – Bits, Bytes and Pixels

Lesson 4: 15.3.2010 – Image Basics – Bits, Bytes and Pixels

Image Types
- Vector images – scalable, direction value, made up of shapes
- Rastor – Working with this at CIT, made up of tones, Photographic Image


Photoshop Fundamentals

· Digital images are made up of a mosaic of pixels. This means that pixel-based images will always have a fixed resolution and is said to be ‘resolution dependant’. If you enlarge such an image beyond the size at which it is meant to be printed, the pixel structure will soon become apparent.
· If the picture is not a photograph but an illustration made from a program such as Adobe Illustrator and the picture is drawn using vector paths the image will be resolution-independent. The image can then be scaled to reproduce at any size. Where the pixel image will start to break up as soon as it’s magnified the vector-drawn image will reproduce perfectly smooth.
· Megapixels to megabytes: If you multiply the ‘megapixel’ size by three you will get a rough idea of the megabyte size of the RGB image output. Eg. A 6 megapixel camera will produce 18 MB RGB images.
· The pixel dimensions of an image are an absolute value. So if you want to know how big an image can be printed, you simply divide the number of pixels by the pixel resolution you wish to print at.
· Number of pixels = physical dimension X (ppi) resolution.
· ppi: pixels per inch – This describes the digital, pixel resolution of an image.


Computer and Image Basics

In order to understand image editing programs and to perform other related tasks you will need a basic understanding of computers and the terminology associated with them.
Bit – ‘Binary Digit’ the smallest unit of a binary number having a value of 0 or 1. This is represented in a computer by an electrical current being off or on, or the direction of a magnetic polarity. It can also be represented optically on media such as CDs or DVDs.

Binary Number – The number system used by computers in which only the digits 0 or 1 are used to represent values. Other systems include decimal numbers (using 10 digits), octal numbers (using 8 digits) and hexadecimal numbers (using 16 digits).

Binary Arithmetic – Mathematical operations such as addition and multiplication can be performed on binary numbers in the same way as we do with decimal numbers.

Byte – A group of 8 bits, this can represent 256 values.

Word – The number of bits that the computer processor can manipulate or process in a single operation. Usually a multiple of 8 eg. 16, 32, 64 etc. This defines how big a number can be represented in the computer, and therefore the amount of memory that can be referenced.

Kilobyte – 1024 bytes

Megabyte – 1048576 bytes

Gigabyte – 1024 megabytes

Terabyte, Petabyte – Even bigger

File Structure – How files and folders (directories) are logically linked together by the operating systems of a computer.

File Extension – A few letter codes following a period appended to the name of a file to help identify the type and contents of a file eg. tiff, jpg etc
Server – A computer that provides services to other computers that are connected to it. Eg. file server, print server, internet server, application server.

Client – A computer that utilizes the services of a server.

Vector – A combination of a direction and a value (eg. length, intensity)

Vector Image – An image described by combining lines and shapes which are defined mathematically. Can be viewed or printed at any size with no loss of sharpness.

Raster Image – An image composed of many individual dots or ‘pixels’ arranged in a grid pattern.
NB: To display any image on a screen it must be converted to a raster image by the computer.

Pixel – ‘Picture Element’ – the smallest component of a raster image. Each pixel has a value representing a colour or a tone.

Bit Depth – The number of bits used to define the shades of colour in an image or in each channel of an image.
Higher Bit Depth = More Shades or Colours
1 bit = 2 values
8 bit = 256 values
etc

Image Size – How big the image is – it may be expressed in a number of ways; Pixel Dimensions, total number of pixels, the size of the image in inches, cm or page size.

Pixel Dimensions – The number of pixels across the width and down the height of an image.

Resolution – The number of pixels or dots per inch or cm.

File Type/ Format – The specification for how the image is described in an image file. It is usually identifiable by the file extension used. Eg. TIFF - .tif, tiff, JPEG - .jpg, .jpeg
One file type may support a number of different image description formats. Eg. TIFF or PSD can save different types of images.

(f) Exercise 1 - Image Uses

(f) Exercise 1 - Image Uses

As a photographer you will be engaged in the task of creating images for a wide variety of purposes. It is important to understand the end use (or uses) of and image in order to create images with specifications most appropriate to the end use. This is important firstly to satisfy the clients needs and secondly to ensure you produce the required images in the most efficient way.

Task 1. Identify as many different types/areas of work a photographer may be engaged in.

1. Architecture
2. Forensic
3. Industrial
4. Photojournalists
5. News Photographers
6. Press Photographers
7. Editorial Photographers
8. Advertising
9. Magazine Photographers
10. Educational Photographers
11. Kids books
12. Book Covers
13. Commercial Photographers
14. Glamour
15. Fashion
16. Catwalk Photographers
17. Event
18. New Born Photographers (In hospital)
19. Documentary
20. Family Portrait
21. Portraits
22. Nature
23. Wedding
24. Freelance
25. Botanical
26. Head shots (eg. For performers)
27. Travel
28. Environmental
29. Fine Arts Photographers
30. Nude
31. Landscape
32. Aerial
33. Food Photography
34. Still Life
35. Paparazzi
36. Underwater Photography
37. War Photography
38. Sports Photography
39. Animal Photography
40. Real-estate
41. Aviation Photography
42. Scientific Photography
43. Astrophotography
44. Emotive Photography
45. Stock Photography
46. Macro
47. Historic
48. Abstract
49. Cityscape's
50. Performance
51. Black and White
52. Jewelry
53. Models
54. Birds
55. People
56. Close Up Photography
57. Pet
58. Transportation
59. Street/Urban
60. Action Photography

Task 2. Select 3 areas of photography.

1. Photojournalism

Photojournalism is a type of journalism that presents a story through images.

-Potential employers include: local papers, international papers, media, news stations, news reporters, magazines, documentary films/books/reports, used promotional by advertisers, celebrities (promotional), organisations

-Ways to display images:
Newspaper - up to full page, low quality image
Gloss Magazine - Double A4 Page - Very high quality
Billboard - 6x10m, medium quality
Website - Size of screen, low resolution
TV Screen - Size of screen, medium quality
Flyers - Up to A4, Low quality
Film - Still Image Screen Size, High Quality

2. Forensic Photographer

A forensic Photographer is employed to capture a crime scene for further reference and investigation.

-Potential Clients: Police, newspapers, news, investigators, government

-Ways to display images:
Newspaper - up to full page, low quality image
Billboard - 6x10m, medium quality
TV Screen - Size of screen, medium quality
Film - Still Image Screen Size, High Quality

3. Wildlife Photographer

A wildlife photographer captures many aspects of wildlife such as animals, plants and landscapes.

-Potential Clients: Magazines, newspapers, Publishers, Books, information brochures, websites, kids books, wildlife groups eg WIRES

-Ways to display images:
Newspaper - up to full page, low quality image
Gloss Magazine - Double A4 Page - Very high quality
Billboard - 6x10m, medium quality
Website - Size of screen, low resolution
TV Screen - Size of screen, medium quality
Flyers - Up to A4, Low quality
Film - Still Image Screen Size, High Quality

Lesson 3: 1.3.2010 - Workflow Introduction

Lesson 3: 1.3.2010 - Workflow Introduction

Lesson 3 was an introduction to the entire process used to the before and afters of taking a photograph. A work flow diagram was drawn up to understand the steps in contracting, taking and printing a photograph. It begins with the contracts and agreements between the photographer and client. The next phase is taking the actual photograph in the form of Digital, Negatives, Stills etc. Step 3 is to upload images to the computer as well as multiple backup points. Step 4 sorting and selecting images before basic editing or if required advanced editing. Next is to prepare the file for output or delivery such as using the appropriate file type and size as well as correct media. You then reach the goal which would vary depending on the contract or prior agreement. It must meet the clients requirements such as digital or hard copy photographs.

Two main aspects to take from this work flow is that as a photographer it is important to be time efficient and bulletproof, eg. BACK UP YOUR PHOTOGRAPHS =]

Lesson 2: 22.2.2010 – Setting Up Your Blog

Lesson 2: 22.2.2010 – Setting Up Your Blog

Lesson 2 took us through setting up our blogs. After a bit of confusion and an entire lesson past, we finally had our blogs created. =]

Lesson 1: 15.2.2010 - Introduction to Imaging 1

Lesson 1: 15.2010 – Introduction

Introduction to Visual Culture

Geoff Woolfenden took us through an introduction to Imaging 1 and explained what we would be covering in the class. Biggest thing that i took out of the introduction was the importance to manage your files!! Having a bit of trouble with using the Macs as I've never used one before but I love the new features to a regular PC.

What We Will Be Covering

- Identify a range of file types and their uses.

- Compare and evaluate methods of uploading digital files using general operating systems and dedicated imaging software.

- Describe and demonstrate the uploading, viewing and outputting of digital files for a range of purposes using general operating systems and dedicated imaging software.

- Discriminate between a range of scanning devices and techniques for specified outcomes including internet use, data projection and photographic printing.

- Identify and explain a range of digital imaging concepts such as colour mode, colour space and bit depth as well as demonstrate typical fundamental digital image enhancement techniques.

- Identify digital image workflow patterns and create a simple file management methodology that conforms to established industry norms.

Starting Photoshop

There are a variety of ways to start Photoshop (or any other application for that matter). 1. Click on it’s icon in the Dock – The Adobe icon expands to reveal all the Adobe products installed. Click on the one you want. 2. Double click on an image file that has Photoshop assigned as it’s application. 3. Drag an image file onto the Photoshop icon on the Dock 4. Select an image file and use the right mouse click to open the drop down menu and select ‘Open with’ and select the application. 5. Select an image file and use the ‘File->Open With-> …’ menu to select the application. 6. Use the Finder to search the Applications folder, then double click on the one you want to start.