Polaroid Cameras I brochure

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The block diagram shows a fast microprocessor, memory, a color display and buttons for a user interface; with a power supply for rechargeable battery operation. That would be a good description for a laptop computer. Add the lens and the CCD module and you have a camera!

All of this processing power means that the camera can make many calculations and decisions while you take the picture.

Before the shot:

Display options on the screen and allow the user to change them with the buttons

Display the viewed image on the LCD screen

Focus the camera

Determine exposure time and whether to fire the flash

Charge the flash, if needed

Determine the color balance to correct for lighting

During the shot

Discharge the CCD

Expose the CCD to the image for the time required

Fire the flash

Stop charging the CCD after the proper exposure is made

After the shot:

Measure the charge on all the elements of the CCD (all 4 million in a 4 megapixel camera)

Convert the voltage on each of the CCD elements to a number

Store the raw image in memory

Read the raw image out of memory and compress it using a JPEG algorithm

Store the compressed image on the memory card

Display the photo briefly on the LCD panel

Calculate memory remaining and display the number of shots remaining.

Sound like a lot of computation. It is! And that’s just part of it, since it must do all that three times to do color!

The focus, exposure and color balance calculations are the principle reason that most people take better photos with a digital camera than with film. Although modern film cameras do an admirable job with focus and exposure control, no film camera can do color compensation. With film you must use a different film for outdoor and indoor shots, or put a filter over the lens.

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Contents Cameras Basic operation and features Why Digital?Why now? Elements of a digital cameraPage Page Megapixel What the heck is a megapixel?Megapixel 4064 x Page Low resolution applications Zoom Optical required, Digital only is not acceptableLCD screen Memory cardsCompression What is a JPEG? Big/Small Rugged/Fragile LensesDigital camera flash Cleaning the lens of a cameraUSB The connection from the camera to the computer Digital camera software What can you do with photo editing software? Photo restoration Batteries File typesJpg Page Some cameras have this setting Some other common features on many camerasPutting it all together Page Printing at the digital kiosk Discussion questions on ethics Addendum Copyright lawDiscussion questions on copyrights Checklist Megapixels Feature/Mode SelectFeatures common to most cameras ZoomPage Addendum 2 Digital cameras versus the Space Shuttle Space Shuttle Camera Computer