Advance Manual : 226-H Technical Presentation
Project # 3 : The Non Technical Audience
Title : Lights to Pixel
Delivered at : Toast of Comsofil Toastmasters Club
Evaluated by : ACB/CL Salvador Villalino
Target Norm : Advance Communicator Bronze
* * * * * *
<<slide 1>>
Who among you here, has seen a digital camera? Or should I say, how many of us here has at least one digital camera. It could be a Point-and-Shoot camera, a miniature camera from a cell phone or a high end one a Digital Single Lens Reflex camera. And I would bet… all us has one way or another, has used a digital camera.
Good evening fellow toastmasters and guests.
How about reversing the question. How many of us here has seen or used a film-based camera? Let me some hands. Gee… there are still quite a few of us who belongs to the Jurassic Era of photography.
<<slide 2>>
Do you still remember that few years ago, camera often looks likes these… and you would carry a bunch of small rolls called films which you load to your camera before taking pictures?
And you would always make sure that every shot you made counts because you are limited to the number of film you have at hand? Of course, we all can relate. Besides, we are in the same age bracket. Isn’t it?
<<slide 3>>
Lately, you may have seen some gizmos or small apparatus that take pictures but in a rather different way. Young adult and even teenagers regularly carry a small Point-and-Shoot camera which we often called a “Digital Camera”. Or perhaps you’ve heard people talked about taking pictures using Web-Camera. And yes, the even cell phones has advanced so much it now carries its own power to take pictures. Teenagers and even kids enjoyed the power of the camera phone they take many picture of themselves and post it to Friendster or Facebook. Those small roll of films simply banished, instead it was replaced with memory cards which can hold up to thousand of pictures vs. few dozen on a film. Perhaps, you can see professional photographers strut their latest digital SLRs to their heart’s content just to show off how expensive their cameras are!
<<slide 4>>
Amidst the advancement of technology, have you even asked this simple question? “How does a camera works “? Perhaps on corollary, you may even ask “How does a digital camera works”?
Let’s take a look! The lens forms the image
In physics, an image may be formed once you put a lens between an image and a converging plane. It is expressed as S1 – the distance between the lens and the object and S2 the distance between the lens and the imaging plane. As per law of physics, the image will naturally appears inverted relative to the orientation of the subject.
For example if you are taking a picture of man, the resulting image would appear as inverted man in the imaging plane.
<<slide 5>>
The phenomenon of projecting an image onto a plane is not new. This was observed during the time of Aristotle who help develop a rudimentary Pinhole Box to observe solar eclipse. We still use Pinhole boxes to observe solar eclipse, do we?
The application was not limited to solar eclipse. They also notice that an image of a tree can be projected inside a Pinhole box. However, the image disappears once the subject was taken out of focus.
The problem now is “How to record or capture the image permanently”
<<slide 6>>
For over a thousand years, the problem lingers. In the early 1000AD, an Arab inventor Alhazen (Ibn Al-Haytham) enhanced the design of the pinhole into a much more complex machine called Camera Obscura. For the first time, a lens was inserted in the hole to magnify the image. They discovered that by changing the lens, they can control the magnification of an image – make it big or make it small.
<<slide 7>>
European inventors tried to improve the design of camera obscura, which eventually became the foundation of modern camera.
Yet, the problem still lingers. The projected image disappears once the subject is taken out of focus.
Did you know that some “ingenious” artist use camera obscura as a template for their paintings. By tracing, they can “capture” the projected image.
<<slide 8>>
A breakthrough happened on the hot summer of 1827. French inventor Joseph Nicephore Niepce successfully made the first photographic image using the Camera Obscura. Instead of tracing, Niepce thought of letting the light draw the image. Niepce’s photographs were produced on a polished pewter plate covered with a petroleum derivative called bitumen of Judea. Bitumen hardens with exposure to light. The unhardened material may then be washed away and the metal plate polished, rendering a negative image which then may be coated with ink and impressed upon paper, producing a print
However, Niepce's photograph required eight hours of light exposure to create and after appearing would soon fade away.
Niépce also began experimenting with silver compounds based on a Johann Heinrich Schultz discovery in 1724 that a silver and chalk mixture darkens when exposed to light.
<<slide 9>>
Joseph made several photographs but it was crude and extremely “ugly”. Most of his works were destroyed or discarded into the waste basket. There is only one known surviving photography made by Joseph. This was taken from the window of his house and took more than 12 hours of exposure.
<<slide 10>>
Niepce’s intuitive idea of allowing the light to draw the image pave way to the advent of photography. The problem shifted on how to capture the image but how to improve the quality of the captured image. Everyone agrees that the answer lies on the type of medium to use.
Niepce’s work on metal and silver was generally categorized as heliographs.
A fellow Frenchman Louis Daguerre found a way to minimize the exposure time to 30 minutes and to keep the image from disappearing afterwards. Daguerre's process 'fixed' the images onto a sheet of silver-plated copper. He polished the silver and coated it in iodine, creating a surface that was sensitive to light. Then, he put the plate in a camera and exposed it for a few minutes. After the image was painted by light, Daguerre bathed the plate in a solution of silver chloride. This process created a lasting image, one that would not change if exposed to light. This method has been known as the Dageurotype.
Other media type were also discovered. Notable among these are:
- Sensitized paper – paper covered with silver salt solution. Invented by Henry Fox Talbot
Talbot sensitized paper to light with a silver salt solution. He then exposed the paper to light. The background became black, and the subject was rendered in gradations of grey. This was a negative image, and from the paper negative, Talbot made contact prints, reversing the light and shadows to create a detailed picture. In 1841, he perfected this paper-negative process and called it a calotype, Greek for beautiful picture.
- Tintypes
Tintypes, patented in 1856 by Hamilton Smith, were another medium that heralded the birth of photography. A thin sheet of iron was used to provide a base for light-sensitive material, yielding a positive image.
- Wet Plate Negatives
In 1851, Frederick Scoff Archer, an English sculptor, invented the wet plate negative. Using a viscous solution of collodion, he coated glass with light-sensitive silver salts. Because it was glass and not paper, this wet plate created a more stable and detailed negative.
Photography advanced considerably when sensitized materials could be coated on plate glass. However, wet plates had to be developed quickly before the emulsion dried. In the field this meant carrying along a portable darkroom.
- Dry Plate Negatives & Hand-held Cameras
In 1879, the dry plate was invented, a glass negative plate with a dried gelatin emulsion. Dry plates could be stored for a period of time. Photographers no longer needed portable darkrooms and could now hire technicians to develop their photographs. Dry processes absorbed light quickly so rapidly that the hand-held camera was now possible.
<<slide 11>>
- Flexible Roll Film
In 1889, George Eastman invented film with a base that was flexible, unbreakable, and could be rolled. Emulsions coated on a cellulose nitrate film base, such as Eastman's, made the mass-produced box camera a reality.
- Color Photographs
In the early 1940s, commercially viable color films (except Kodachrome, introduced in 1935) were brought to the market. These films used the modern technology of dye-coupled colors in which a chemical process connects the three dye layers together to create an apparent color image
- Digital Sensors
First introduced in early 1980s, digital sensor slowly gain acceptance as the medium of choice for photography. As the advances of technology flourish, the initial problem on digital sensor eventually vanish. At present, the quality of digital sensor has reach the level of that in film and some pundits even claim it has surpass it. If you look around, 99% of camera are powered by digital sensor: may it be phone camera, point-and-shoot up to the powerful DSLRs.
<<slide 12>>
From plates to film to the current trend in sensor and memory cards, what do you think would be the future?
Back to you evening master!
