Task 1

1. What is the earliest reference of photography?

The earliest reference to photography came from Chinese philosopher Mo Ti in the early 5th century, he formally recorded the creation of an inverted image formed by light rays passing through a pin-hole in a darkened room. He called this room the 'collecting place' or the 'locked treasure room'.

2. Who created the first camera obscura?

The camera obscura was not built until the 10th century by Alhazen an Islamic soldier and scientist who's experiments included placing five lanterns outside a room with a small hole. The term "camera obscura" was first used by the German astronomer Johannes Kepler in the early 17th century. He used it for astronomical applications and had a portable tent camera for surveying in Upper Austria.

3. Draw a diagram showing how a pin-hole camera works. 

4. Who was the person responsible for the first permanent camera image.

The first person to create a permanent camera image was Joseph Nicéphore Niépce in 1826. In the window of his upper-story workroom at his Saint-Loup-de-Varennes country house, Le Gras, he set up a camera obscura, placed within it a polished pewter plate coated with bitumen of Judea (an asphalt derivative of petroleum), and uncapped the lens. After at least a day-long exposure of eight hours, the plate was removed and the latent image of the view from the window was rendered visible by washing it with a mixture of oil of lavender and white petroleum which dissolved away the parts of the bitumen which had not been hardened by light. 

5. What are two ways to control the amount of exposure of a photograph?

Two ways to control the amount of exposure of a photograph are adjusting shutter speed and aperture settings.
Shutter Speed : The shutter blocks all light from exposing the sensor until you press the button. Then it quickly opens and closes giving the sensor a brief flash of light. You control the length of time the shutter remains open by setting the shutter speed, longer shutter speeds =more light, shorter shutter speeds = less light.

Aperture: Before light reaches the sensor it must pass through an opening called an 'aperture'. You can control the Aperture by setting the 'Aperture opening' also known as f - stop.

6. Name two shutter types and briefly explain how they operate.

Electronic shutter: turns the sensor on and off to capture the exposure. The image is built up as the light is captured by the sensor. Camera's with the electronic shutter can be exceptionally accurate when designed with precision.

Leaf shutter: is a type of camera shutter consisting of a mechanism with one or more pivoting metal leaves which normally does not allow light through the lens onto the film or digital image sensor, but which when triggered opens the shutter by moving the leaves to uncover the lens for the required time to make an exposure, then shuts.

7. What is an f-stop?

F-stop is how Aperture is measured, each stop represents a factor of two in the amount of light admitted. The photographer makes adjustments to the opening of the diaphragm by setting the f-stop. F-stop is the ratio of the focal length of the lens to the diameter of its opening. The larger the numerical value of the f-stop, the smaller the opening of the aperture.

8. What is an f-number?

 An F-number also known as a focal ratio, is the ratio of the diameter of the lens aperture to the length of the lens. On a camera, a photographer can alter the f-number by changing the f-stop setting on the camera’s lens. Each increment of an f-stop (and, thus, and f-number) represents a decrease of light entering the lens by half the previous intensity.

9. What does exposure mean?

Exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph. Exposure is measured in lux seconds, and can be computed from exposure value (EV) and scene luminance over a specified area.

10. If exposure = time x intensity, what does time stand for and what does intensity stand for? (hint look at question 5)

Exposure = shutter speed (time) x aperture (intensity)