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CAMERA ANATOMY

http://www.youtube.com/watch?v=j-kWYvuLmqM

When you strip it down to it’s most basic construction, a digital camera is no different than a film camera from 150 years ago.

All camera designs begin with a lightproof box.

On one side of this box sits the lens for focusing light and on the other side sits the focal plane (the area the lens focuses on.)

A VERY FANCY BOX

The focal plane holds a light sensitive recording medium of some kind.

In an 18-century camera obscura, this might have been a big piece of paper – the photographer would trace over the projected image to create a drawing or painting.

In a digital camera,, the focal plane houses, a digital image sensor.

FANCY BOX CON’T.

An image sensor is a special light sensitive silicon chip.

2 Major Chips on the market, Charged Couple Device (CCD) and Metal Oxide Semiconductor (MOS)

WHAT DOES AN IMAGE SENSOR DO?

1) When taking a picture, the light falling on the image sensor is sampled and converted into electrical signals.

2) After the image sensor is exposed, these signals are boosted by an amplifier and sent to an analog-to-digital converter that turns the signals into digits.

3) Finally, the digits are sent to an on board computer for processing, which is saved to the memory card.WHAT DOES AN

IMAGE SENSOR DO, CON’T?

A great advantage that digital cameras have over film cameras is the smaller size of the image sensor. (They don’t need to hold film inside of them)

As light falls on the image sensor, the camera turns it into an image and passes that image onto the LCD screen (Viewfinder.)

POINT-AND-SHOOT DESIGN

A Point-and-Shoot with an optical viewfinder, uses an entirely separate lens for the viewfinder.

The main camera lens is used to expose the sensor, while the optical viewfinder looks through a different lens.

Optical View finder shows you 80 -85% of final image, while LCD screen shows you 98 – 100% of final image.

POINT-AND-SHOOT DESIGN

SLR only has one lens, as apposed to the Point and Shoot, which houses the sensor, and one for the optical viewfinder.

When looking through a viewfinder of an SLR, your looking through same lens that exposes the image sensor.

If you look at the profile of your SLR, you’ll see that the lens is actually sitting much lower than the viewfinder.

SLR DESIGN

If you were to saw your camera in half, you would find the image sensor and shutter, sitting directly behind the lens.

In front of the shutter, you would find a mirror set at a 45 degree angle. The mirror bounces the light from the lens up toward the top of the camera.

The light enters the prism and is redirected out through the viewfinder.

SLR CON’T

SLR ANATOMY