Sunday, August 5, 2007

An Eye for the Camera...

Here is a comparison between the Eye and the Camera... Although the concepts or principles concerning the camera is based on the functions and capabilities of the human eyes, it has advantages, similarities, differences and disadvantages as compared to our visual organ...

HUMAN EYES vs. CAMERA Human eyes have often been compared to cameras. They are alike in terms of structure, but they have one fundamental difference in functioning mechanism.


Similarities:
1. opening for light to enter aperture pupil
2. control the amount of light entering camera/eye diaphragm control size of aperture iris muscles control size of pupil
3. refract light glass biconvex lens mainly cornea ;
lens, aqueous & vitreous humor
4. object of light action to form image photosensitive chemicals on film photoreceptors(rods & cones) in retina
5. absorb excessive light to prevent multiple images formation dark internal surface pigmented, dark choroid

Difference:
1. focusing mechanism change distance between lens & film change focal length of lens using ciliary muscles


And here's a short and brief origin of the modern cameras...
Camera obscura.
The forerunner to the camera was the camera obscura. The camera obscura is an instrument consisting of a darkened chamber or box, into which light is admitted through a double convex lens, forming an image of external objects on a surface of paper or glass, etc., placed at the focus of the lens.[4] The camera obscura was first invented by the Iraqi scientist Ibn al-Haytham (Alhazen) as described in his Book of Optics (1015-1021).[1] English scientist Robert Boyle and his assistant Robert Hooke later developed a portable camera obscura in the 1660s.[2]
The first camera that was small and portable enough to be practical for photography was built by Johann Zahn in 1685, though it would be almost 150 years before technology caught up to the point where this was possible. Early photographic cameras were essentially similar to Zahn's model, though usually with the addition of sliding boxes for focusing. Before each exposure, a sensitized plate would be inserted in front of the viewing screen to record the image. Jacques Daguerre's popular daguerreotype process utilized copper plates, while the calotype process invented by William Fox Talbot recorded images on paper.

The first permanent colour photograph, taken by James Clerk Maxwell in 1861.
The first permanent photograph was made in 1826 by Joseph Nicéphore Niépce using a sliding wooden box camera made by Charles and Vincent Chevalier in Paris. Niépce built on a discovery by Johann Heinrich Schultz (1724): a silver and chalk mixture darkens under exposure to light. However, while this was the birth of photography, the camera itself can be traced back much further. Before the invention of photography, there was no way to preserve the images produced by these cameras apart from manually tracing them.
The development of the collodion wet plate process by Frederick Scott Archer in 1850 cut exposure times dramatically, but required photographers to prepare and develop their glass plates on the spot, usually in a mobile darkroom. Despite their complexity, the wet-plate ambrotype and tintype processes were in widespread use in the latter half of the 19th century. Wet plate cameras were little different from previous designs, though there were some models, such as the sophisticated Dubroni of 1864, where the sensitizing and developing of the plates could be carried out inside the camera itself rather than in a separate darkroom. Other cameras were fitted with multiple lenses for making cartes de visite. It was during the wet plate era that the use of bellows for focusing became widespread.

***Here are some site feeds from http://library.thinkquest.org/28030/eyeevo.htm and http://en.wikipedia.org/wiki/Camera... I just think the sources deserve due respect and recognition for their works as published in my blog... Please, do not support plagiarism... Just passin by... Leave a message on my tagboard if you wish to copy some posts in this blog and your site as well... thanks...

1 comment:

Anonymous said...

Good for people to know.