How Digital Cameras Actually Work.

March 06, 2015  •  Leave a Comment

Welcome to another edition of "Theoretical Thursday", where we attempt to make the complicated even more complicated...

Actually we do our best to simplify all things photographic so that everyone can enjoy it! 


This time, we're going to attempt to explain the AMAZING process of how a digital camera works! 

Sure, it's easy to think that THIS is what is inside a digital camera that makes it work...

However, that's not really the case...



This one is definitely going to involve some "science" so hold onto your hair!


First, a bit of history behind things...

Before photography was invented by some really smart French guys, the only pictures people looked at were drawings and paintings.

Well, that and shadow puppets in opium dens...but that's totally a different thing. 

However, cameras did exist!!! 

This big crazy thing being shown is called a "Camera Obscura".  It was extremely popular for artists/painters back in the 16th, 17th and 18th centuries.  However, building a huge room to be able to accurately paint a scene was a bit of a pain.

They eventually figured out a way to build "table top" Camera Obscuras.  Still allowing the artist to be able to paint from life more accurately.


This whole process is genuinely what eventually led to the "discovery" of the process of "photogravure" or "photography" in the early 1800's.




Sorry...It's a little slow going for a few minutes till we get to where we're going.

Essentially, this is how a camera obscura works, as well as a photographic camera.  

A. The "envisioned scene" B. A lens to focus/harness the image. C. Focused image which is inverted by the lens.


Long story short and some 150 years of technological evolution later...Film Cameras looked/operated much like this above.

The scene goes into the lens, it's flipped around and the shutter opens at a set timing to allow the image to "imprint" upon special chemically treated film that absorbs light and "records" the image. -How's that for a "thumbnail sketch" of things?


Film photography reigned supreme for many years...and then scientist/photographers lead once more into photography history and came up with something called a "digital" camera.  The first ones literally were film cameras with a crude digitization sensor/processor that produced very rough images.  But then again, the first photographic image was a pretty crude one.

For comparison's sake.  Above, the first photographic image ever.  Below, one of the first digitally rendered photographic images ever.

This was the surface of the moon as seen digitally in 1979.  Yeah.


Here's a really good diagram about what happens in terms of digital photography.

The scene,lens,sensor(film),processor(microcomputer),and image.

If you look at it in terms of the original camera obscura and also how a film camera work, you start to see the similarities. 


Here is a REALLY GREAT diagram of how photography works in digital. (Courtesy of digital camera world.)


So, to not get too bogged down into "technospeak" Light goes into/through the lens, goes through an Red/Green/Blue filtering process.  The light reacts with the sensor...The sensor does the sensing.  The sensor then allows the light reaction to be converted on the backside by converters and processors and eventually gets recorded in a series of super teeny tiny "pixels" that correspond to numerical information spit out by the processor/converters that results in an image.


It literally is a wonder of science that his can take place within the matter of a second or two depending on the quality/build of the camera.

Next time you pick up that camera to snap a few photos...Stop and think about what all is going on inside that little machine.  It's a lot more than just "point and shoot".


Thanks for reading and tune in next time for "Who the hell is .JPEG and what does he want with my pictures???" 



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