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The Basics: Light and How The First Cameras Worked
The Basics: Light and How The First Cameras Worked
Imagine you are standing in the middle of a room with no windows, doors or lights. What do you see? Well, nothing because there’s no light. Now imagine you pull out a flashlight and turn it on. The light from the flashlight moves in a straight line. When that beam of light hits an object, the light bounces off that item and into your eyes, allowing you to see whatever is inside the room.
All light behaves just like that flashlight — it travels in a straight line. But, light also bounces off of objects, which is what allows us to see and photograph objects. When light bounces off an object, it continues to travel in a straight line, but it bounces back at the same angle that it comes in at.
That means light rays are essentially bouncing everywhere in all kinds of different directions. The first camera was essentially a room with a small hole on one side wall. Light would pass through that hole, and since it’s reflected in straight lines, the image would be projected on the opposite wall, upside down. While devices like this existed long before true photography, it wasn’t until someone decided to place material that was sensitive to light at the back of that room that photography was born. When light hit the material, which through the course of photography’s history was made up of things from glass to paper, the chemicals reacted to light, etching an image in the surface.
Camera Obscura:
It all started with camera obscura... which is basically just a box with a pinhole. The light reflecting off of an object goes through the pinhole and projects its image on the far side of the box. This was used by artists to "copy" images from real life.
2. SILVER NITRATE SENSITIVITY- JOHANN HEINRICH SCHULZE (1727)
2. SILVER NITRATE SENSITIVITY- JOHANN HEINRICH SCHULZE (1727)
Schulze discovered that silver nitrate darkened when exposed to light. This was the first step in being able to "record" an image made from light.
3. FIRST PHOTO- JOSEPH NICEPHORE NIEPCE (1826)
3. FIRST PHOTO- JOSEPH NICEPHORE NIEPCE (1826)
The first photo was made by using a pewter plate that was covered in bitumen and exposed to light. The light areas hardened the bitumen and the rest of the areas were washed away with the oil of lavender. The resulting image revealed light regions of hardened bitumen and dark areas of bare pewter.
Advantage: A photo!
Disadvantage: It took 8 hours of exposure time! And the image somewhat fades.
Since that first camera did not capture very much light, it actually took eight hours to take a single photograph. The image was also quite blurry. So how are we able to take sharp images in milliseconds today? A camera lens.
While light bounces off of objects, it can also pass through objects — but, when it does, it can actually change direction. A camera lens takes all the light rays bouncing around and uses glass to redirect them to a single point, creating a sharp image.
When all of those light rays meet back together on a digital camera sensor or a piece of film, they create a sharp image. If the light doesn’t meet at the right point, the image will look blurry or out-of-focus. A lens’s focusing system moves the glass piece closer or farther from the sensor or film, allowing the photographer to adjust the lens so that the object is sharp.
Distance also plays a role in how camera lenses are able to zoom in. When the front piece of glass moves farther away from the camera sensor, objects become closer. Focal length is the measurement of the distance between where the light rays first hit the lens and where they reach the camera sensor. For example, on a lens with a 300mm focal length, the light takes 300 mm to be directed back into a sharp point on the camera sensor. A 300mm lens is considered a telephoto, or a lens that’s able to bring far objects close.
4. DAGUERREOTYPE- LOUIS DAGUERRE (1838)
4. DAGUERREOTYPE- LOUIS DAGUERRE (1838)
This was the first-ever photo of a human! Can you find the man getting his shoes shined? He stayed in one place long enough for the camera to record him. Others were walking around the street but their image was not recorded because they were moving around.
In this process, the exposure plate is treated with mercury fumes to make it more sensitive. The exposure time goes down to 30 minutes (instead of 8 hours).
Advantage- Faster exposure and more permanent image.
Disadvantage- Still took 30 minutes to take a photo.
6. CALOTYPE- (COPIES!)- WILLIAM HENRY FOX TALBOTT (1841)
The image was made as a "negative," from which a "positive" copy could be made. For the first time, multiple copies could be made of an image.
6. CALOTYPE- (COPIES!)- WILLIAM HENRY FOX TALBOTT (1841)
The image was made as a "negative," from which a "positive" copy could be made. For the first time, multiple copies could be made of an image.
Advantage- Multiple copies could be printed
Disadvantage- 30 minute exposure time
7. COLLODION PROCESS- FREDERICK SCOTT ARCHER (1851)
The exposure plate is treated with collodion (a liquid chemical) which makes the plate extra sensitive to light. Exposure time is reduced to 2-3 seconds.
7. COLLODION PROCESS- FREDERICK SCOTT ARCHER (1851)
The exposure plate is treated with collodion (a liquid chemical) which makes the plate extra sensitive to light. Exposure time is reduced to 2-3 seconds.
Advantage- Faster exposure!
Disadvantage- Messy and not portable. Plate needs to be exposed and printed right away.
10. FLEXIBLE PHOTO PAPER- GEORGE EASTMAN (1884)
Film!
Advantage- Many exposures, very portable, could be sent away for development
10. FLEXIBLE PHOTO PAPER- GEORGE EASTMAN (1884)
Film!
Advantage- Many exposures, very portable, could be sent away for development
Disadvantage- ???
DIGITAL SENSORS
DIGITAL SENSORS
Switching from film to a digital sensor allowed images to be further manipulated.
Advantage- Delete unwanted exposures, digital manipulation
Disadvantage- ???
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