Digital Photography Complete Course: Learn Everything You Need to Know in 20 Weeks

Book Preface

Photography is more popular than ever before,  with billions of photos shot and shared each year.  If photography has never been so popular it  is largely because it has never been so simple.  Sophisticated modern cameras make it easy to  shoot and upload photos, while editing software  can give dramatic results. The downside is that  this exciting technology makes it all too tempting  to ignore the fundamentals of photography.  This book is a comprehensive guide to  photographic principles. It is divided into 20  modules, each of which follows the same stepby-step pattern and can be tackled in one week.  By the end you will understand what it takes to  make a good photo, and you will be a confident,  well-rounded photographer with a broad range  of skills and knowledge

Improving your photography means taking full  control of your camera. Many smartphones and  compact cameras lock you out or restrict control  of certain aspects of photography, such as the  ability to set exposure. To get the best out of  this book, it’s highly recommended that you use  either a bridge camera (also known as a hybrid  or prosumer) or an interchangeable lens system camera (or system camera for short). The latter  type is preferable because, as the name suggests,  you can swap lenses to suit a particular task.  System cameras also let you expand their  capabilities by adding other accessories, such  as flashguns. System cameras can be neatly split  into two groups: digital single lens reflex (dSLR)  and mirrorless.

Inside every digital camera  is a light-sensitive surface  called a digital sensor. When  you press the shutter button to take a photo, the sensor collects  and records the exact amount  of light that falls onto it. This  information is then converted  in-camera into the data that’s  needed to make a digital image.

Seeing the light Light either reaches the camera  direct from the light source (1) – this is known as incident light –  or it bounces off objects in a scene  before it reaches the camera (2).  This is known as reflected light.

Exposing an image A digital sensor is covered in  millions of microscopic cavities  known as photosites. When  exposed to light, particles of  light (photons) fall into the  photosites. When the exposure  ends, the camera meticulously  counts the number of photons  in each photosite and uses this  information to create a photo.  The darkest areas of the image are  those where the fewest photons  were recorded by the photosites.  Brighter areas are where more photons were recorded.

Converting light
In order to create a sharp photo, light must be focused  precisely onto the sensor. This is achieved through the  use of a glass (or plastic) optical system known as a  lens. The amount of light reaching the sensor is  controlled by two physical mechanisms.

The first is an iris inside the lens  known as the aperture. The second  is a mechanical curtain called the  shutter that sits directly in front  of the sensor. These two controls  effectively work like a tap that  enables you to turn on and  off the flow of photons  reaching the sensor.

When you press the shutter  button, the shutter opens to  reveal the sensor, stays open for  a period known as the shutter  speed, and closes. The camera  analyses the light and produces  an image which is written to the  memory card.

Colour A photosite on its own only  records levels of brightness.  To record colour, a colour filter –  red, green, or blue – is placed  over each photosite. This filtration  blocks colours of light that are  dissimilar to the filter. A cluster  of one red, two green, and one  blue photosite is combined by  the camera to make up one pixel in the final photo.

Modern digital cameras are  far more complex devices than  their film-based cousins. A  digital camera is essentially a  computer designed solely for  creating pictures. This involves  a large number of external  dials and menu options to  control the camera’s functions,  which will vary from model  to model. Fortunately, once  you’ve mastered one camera,  it’s generally simple to get to  grips with another, particularly  if you stick to the same brand.