Wednesday, April 7, 2010

Adding up...

You would think when you join up as an art major, you wouldn't have to deal with math anymore... right? Wrong! Wrong, wrong, wrong!

Anyone who's studied photography knows that the main factor is light. There are two variables: aperture (how big the opening gets) and shutter speed (how long the shutter stays open). Both basically fulfill an equation that looks something like this:

light coming in x time= exposure

Lost yet? Yeah, that's what I thought. So I made a little diagram...

So in other words, you need a certain amount of light and the two factors have to balance that out. But--since each has a different effect-- you might want to swap one for the other. This is known as reciprocity. Like so....
Got it? Good. Now I'm going to let you in on a little secret... if the exposure is too long (when using film) there's this loving thing called reciprocity failure. That's right. The simple back and fourth FAILS! This just goes to show that math and science isn't everything it pretends to be.

You see, if your shutter speed is too long, all the sudden you need MORE time to make sure enough light gets in. I'm sure someday this odd fact will start to make sense to me, but for now... it's proof to me that math is completely overestimated and unpredictable.


  1. I have no clue what you just said! Haha! But kudos to you! :-)

  2. I don't have a clue either. Math smarts waved bye-bye to me when they started putting letters with the numbers.
    Good luck with the fun part of photog stuff!

  3. Photography is SO confusing to me. I have two beautiful film cameras, but have basically no idea how to use 'em. All the shutter speed, light, and aperture talk goes way over my head.