Saturday, January 31, 2009

Advancing Technology in Digital Photography

How long do you think it would take you to count to 1 million?  I remember being about 10 years old and walking down to the end of the street I lived on.  Then continuing on a dusty trail through a field towards a pasture or a creek.  This was one of my usual haunts after school.  This particular day I decided the moment I got to the bottom of our driveway I would begin counting to see how long it would take to get to 1,000 and where I would be when I got to 1,000.  I was about halfway thru the field at the end or our street.  Looking back is was probably a third of a mile.

For this thought experiment let's suppose on average it will take you 3 seconds to pronounce each number from 1 to 1 million and begin pronouncing the next.  Counting day and night without stopping it would take 34 days 17 hours.  To further underscore the point I am about to make I seem to recall my church in Hot Springs organizing an event on government park property in which the word of God, the Bible would be read, by volunteers, without stopping from Genesis to Revelation.  This took just a weekend.

Now that I've set you up have you ever thought about what 10.1 megapixels mean in terms of say an ordinary Sony Cyber-Shot camera?  To capture a color photograph recall that light is made up of 3 primary colors red, blue, yellow.  An equal combination of these 3 colors give you something close to a white light.  Contrast this to food dye or buckets of paint.  It is just the opposite.  The combination of a drop each of red, blue, and yellow dyes give you something close to black when all blended.  Therefore 1 pixel is made up of 3 sensors tuned to just sample the 3 primary colors.

These samples are graded in brightness to maybe a thousand levels.  Now you have 3 color sensors X 10.1 million pixels equalling 30.3 million individual sensors in a space of about 1 centimeter by 1/2 centimeter square.  This is a solid state sensor device manufactured to precise levels such that if you have so much as 3000 defective pixels your picture of your friend's birthday party would be defective and you might be able to tell.  Back to Walmart it goes for an exchange.

The computer inside your digital camera has to record all this information and assimilate 30.3 million individually addressed sensors within the time it takes for you to become impatient AND before you jiggle the camera.

Now this article is not meant to be factually conclusive but if I am wrong in some aspect let me know.   People handle their cameras like aborigines handle a didgeridoo without ever appreciating or understanding what makes them work.  In fact a didgeridoo might be handled more sacredly.  Thoughtful people collaborated to make these cameras possible and it is amazing that they even work as long as they do.

Oh, and the display on the back of your camera is nearly as much of a feat as the camera.  The display is a piece of laminated glass that is nearly clear except for a slight gray appearance.  About half as thick as a Saltine Cracker the glass display is layered together with two pieces of precisely polarized fresnal lenses made of plastic film not much thicker than Saran wrap.  Behind all that is yet another thin film of electroluminescent plastic that serves to backlight the display.  When a certain volatage is applied to this plastic it glows that familiar LCD screen glow.

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