As the world is changing, so is the technology. Everyday humans make new discoveries filling in the vast gulf of information for the betterment of mankind. From steam engines to bullet trains, man has evolved from caves to skyscrapers making life easier for him and for his generations to come.

Though timers have been in use for centuries, which could have imagined their use in digital cameras to produce the most authentic and life like images this world has ever seen. Timers have revolutionized the field of photography. As the world has advanced from conventional darkrooms to computer soft-wares, so have the timers. Various types of timers have been invented over the years which include:

• Digital timers
  
• Electromechanical timers
  
• Electronic timers
  
• mechanical timers
  
• computer timers
  

According to web definitions, a timer is basically a special type of a clock which can be used to control the sequence of an event. These can be used in cameras to achieve high precision and good quality. Cameras like Nikon, Olympus, Agfa, and Sanyo use timers to let the user take pictures without touching the camera.

Uses:

• Mechanical timers are the oldest form of timers used. These are used in small alarm clocks and can be used without batteries.
  
  
• Electromechanical timers are basically used in aerospace and weapon systems. These timers controlled the launch sequence of rockets and missiles.
  
  
• For higher precision and accuracy, digital timers are used. These operate on due to quartz crystal which controls the frequency of the timer.
  
  
• The number of timers in a computer varies. Computers normally have one to sixteen electronic timers.
  

Timers can also be used as darkroom accessories. Portable timers can be used to turn external circuits either on or off automatically. It can also be used to signal the end of an interval. It consists of an easy to read dial which gives both elapsed and remaining time. It also consists of a buzzer which signals the end of an interval. It has an accuracy of +/- 0.015% at maximum dial setting.

Types of darkroom timers:

• General purpose timer
  
• Darkroom timer with a luminescent dial
  
• Digital electronic darkroom timer
  
• Digital darkroom timer
  
• Timer footswitch
  
• Interval timer
  
• Maylan stopwatch
  

A number of timers are available in the market. Some of them work just like normal kitchen timers and the other ones have memories and are capable of handling precise time intervals. Timers are utilized twice during the print. Basically there are two types of timers: enlarger and processor timers. The enlarger timer controls light settings on the enlarger, whereas process timers count down the time intervals. The best process timers can be read and set in the dark. The advanced process timers will also have memories. Digital timers are modern timers and have time settings in memory, these are more precise and have fractional settings which are easy to set and repeat. The earlier period timers, for instance the Time-o-Lite, are mechanical count-down timers. The timer is set for the desired time and when it reaches to 0 it automatically resets to the preferred time.

The extensively used darkroom timer is Gralab model 300. The minutes and seconds can be set in a time range of 60 minutes. It also consists of an electric synchronous motor which assures high accuracy and precision. It has an eight inch luminous dial which can be easily read in the darkroom. It has keyholes in the back which create wall mounting simple and a three wire grounded cord.