Digital Photography (Short Course)

Take a step toward working in photography? 

You will need access to a digital camera and some type of storage or output device during the course.

This is required so that you can take some photographs on a digital camera and submit them as a print or as a digitised file. An inexpensive digital camera and a printer or 3.5 inch floppy disk would be a minimum. If you plant o purchase a digital camera, but have not yet decided what to buy, it is recommended that you delay buying a camera until you have completed Lesson 3 and commenced Lesson 4. It is also suggested that you ask your tutors advice as to which camera would best suit your needs. Access to a suitable computer is also advantageous but not essential.

Lesson Structure

There are 11 lessons in this course:

1. Introduction To Digital Technology: How images are captured and stored, categories of equipment & software, scope of applications
2. Equipment -getting started; deciding what you need : CCD's, Image Sizes, Raster Images,, Video Cards, Colour depth, Computer terminology etc.
3. Digital Technology: Colour, resolution, sensors (how technology enables digital images to be captured).
4. Digital Cameras: Image formation, lenses, camera stability, one shot cameras, 3 shot cameras, terminology (eg.DPI, DVD, Bit, EDO RAM, Plug In etc)
5. Taking Photographs: Principles of Photo Composition, Creating effects, Default Setting, Compression of Data, Dithering, Halftones etc
6. Scanning Images : Techniques which can be used for digitally capturing images from film photographs, or graphics
7. Uploading Images : How digital images can be transferred effectively from a camera (or scanner) onto another device (eg. a computer, video monitor, television set, etc).
8. The Digital Darkroom: Techniques that can be used to process digital photographs within a computer to achieve improved or changed images
9. Compositing & Imaging - Production & manipulation of images; How digital photos can be manipulated and changed to produce altered images
10. Special Effects: Scope and nature of special effects that can be created with digital photographs
11. Outputs & Applications- Printers, The Internet; How and where digital photography can effectively be used.

Aims

• Describe the scope and nature of digital photography
• Select appropriate equipment for use in digital photography
• Explain how technology enables digital images to be captured.
• Compare different digital cameras and select an appropriate camera for a particular application.
• Control the effects created in a digital photograph which you take.
• Describe techniques which can be used for digitally capturing images from film photographs, or graphics.
• Explain how digital images can be transferred effectively from a camera (or scanner) onto another device (eg. a computer, video monitor, television set, etc).
• Describe techniques that can be used to process digital photographs within a computer to achieve improved or changed images.
• Explain how digital photos can be manipulated and changed to produce altered images.
• Discuss the scope and nature of special effects that can be created with digital photographs.
• Identify how and where digital photography can effectively be used.
• Digital photography is a radically different technique to film photography which records images in the form of digital (ie. 2 digit or binary) codes. In simple terms digital codes are similar to Morse code. One number or digit is indicated by a pulse of electricity, a second digit is indicated by no electrical pulse. By combining these pulses and lack of pulses into codes, we can, for example, create representations for letters of the alphabet; allowing us to write language or text on a computer. When we combine these electrical "pulses" and "no pulses" (or ‘ones’ and ‘zeros’) in more complex combinations, we can create more complex representations. These can include the colour, and degree of darkness or brightness in a single spot on a picture.

What You Will Do

• Investigate software available for processing digital photographs
• Obtain literature on Adobe Photoshop and any two other types of software.
• Compare the different software options which you investigate.
• Develop a check list of what would be required if you were to purchase a digital camera for professional freelance photographic work (such as studio portraits and wedding photography)
• Find five photographs you have taken in the past which have not been as successful as you would have liked. Consider what you might have done to improve the way in which the image was taken in each of these. Consider what advantages digital photography might have offered if you had taken these using a digital imaging rather than film.

Digital cameras and film cameras work in much the same way in most respects. The only major difference is that a film camera captures the image through a chemical process on film, whereas a digital camera captures the image through an electronic process into an image sensor and into memory.

If you understand conventional photography, you already understand most of the operations of a digital camera.

IMAGE FORMATION

If a small hole is made in the wall of a dark room or, as may have been in ancient times, a tent, the action outside the room or tent would be seen, projected onto the interior wall opposite the hole, the picture being inverted left for right and upside down. This phenomenon was almost certainly known since ancient times.

This is how the earliest examples of image formation were achieved.

• Light can only travel in straight lines, and it can only move around a corner or angle by reflection.
• Given that light only travels in straight lines, an image is formed as follows:
• Imagine a standard lamp outside a dark room. Light rays are reflected from all parts of the standard lamp in straight lines.

If there is a hole in the wall of the room, some of these light rays will pass through that hole in the wall.

Light rays coming from the top of the lamp at a downward angle relative to the floor will meet the opposite wall close to the floor inside the room. This creates an image of the top of the lamp at close to floor level.

Light rays coming from the bottom of the lamp travel at an upwards angle through the hole to meet the wall close to the ceiling on the opposite wall. This creates an image of the bottom of the lamp near the ceiling.

The hole acts to restrict the transmission of light so that only the rays which enter it at the correct angle from the subject will pass freely through and form an objective image of the lamp. As a result, the rays are "selected" by the hole. The image is both upside down and inverted left for right. Rays that could form a correctly oriented image are diverging from the lamp in opposite directions and cannot form an image.

Box rooms were known as "Camera‑Obscura" or "Dark Chambers".

The camera obscura, is historically the forerunner of all modern cameras and has lent its name to them. Today it is perpetuated, in miniature, by the pinhole camera.

LENSES

One of the most significant developments in photographic history is the lens. Lenses probably originated when some distant ancestor happened to notice that a rounded crystal they were holding seemed to form an image of the sun on the ground, much the same as a magnifying glass.

The first practical lens for a camera obscura was designed in 1812. The first lens specifically made for photography was produced around 1840. Lenses operate on the principle called refraction. Although light moves in straight lines, its rays can be bent (or rather turned onto a different angle), when passed through a lens.

WHAT HAPPENS TO MAKE IT LOOK BENT?

• Light does not travel at the same speed through all transparent materials.
• When light illuminating your pencil or knife enters the water, it changes speed (slows down). As it does so, it changes direction to a new, straight-line course.
• This leads to the light being reflected from the object in the water being ‘refracted’, to a different angle before reaching your eyes.
• This is what makes the pencil or knife look bent.

The principle of refraction is the basis of all lens design.

The degree to which light ‘bends’ is dependent on two factors:

1. The angle the light hits the surface of the new medium which it is being passed through (eg: Water, glass etc).

2. The type of material the light is entering.

The simplest photographic lens uses this principle to refract and focus light. This is called a "biconvex lens”, having two outwardly curving surfaces. A magnifying glass is such a lens. A ray of light entering a biconvex lens is refracted

RECOMMENDED BOOK

ACS Distance Education also offers a wide range of eBooks to complete our courses. You may be particularly interested in our Photographic Techniques eBook.

Explore how to take better photos. This is a book packed full of practical tips, from the authors own experience, coupled with a solid introduction to well established and widely practiced photographic techniques. This is a well illustrated, excellent reference for students of photography; and an equally useful source of inspiration to the amateur photographer.