When a friend of mine heard that I'd bought a new camera, he joked that he was going to quiz me on ISO and Shutter Speeds on the following Monday.  It's a good thing he was joking because I had zero idea what he was talking about :)  Since I'm a total beginner at photography I asked around for book suggestions and was told by several people that Understanding Exposure by Bryan Peterson is a great book to start with.

One of the first things it had me do was set the camera to M (manual mode) and go out in the back yard to try and get a "Correct Exposure".  First of all...this was horrifying since I've never even tried shooting Manual Mode before.  Also, I had no idea what a Correct Exposure was, so I went back to the manual on my camera to see if I could figure it out.

It turns out cameras are actually pretty smart on their own and use a system for letting you know what shutter speed you need based on your current ISO and Aperture settings.  So the above image is shown in the viewfinder to let you know if you are letting too much or too little light on the exposure.  When the dot is dead center, as shown above, that means you have achieved a Correct Exposure.

So, I headed into the back yard and set the Aperture to 5.6 and the ISO to 400..that meant I needed to adjust the shutter speed to 200 in order to get my Correct Exposure.  This achieved the image above of my favorite test subject (he will actually sit still for long periods...unlike my son).

Bryan gives a great example for how Aperture, ISO and Shutter Speed work together to creating an exposure.  He describes the lens opening (Aperture) as a kitchen faucet opening at f/11 and imagine there are 200 worker bees(ISO) with buckets below the opening of the faucet.  The water coming through the faucet is the light and the shutter speed needs to be set correctly so that the exact amount of water comes through to fill the 200 buckets exactly.  This is what setting the shutter speed does for an exposure and when it shows Correct Exposure then you have the right setting for that shot.

The next thing I learned is there are multiple Correct Exposures for a shot depending on what you set the ISO and Aperture to.  Each shot has a different result depending on motion in the scene, etc...but they are still all "correct".  To give an example of what I mean, I've taken the same shot of my moving ceiling fan three times with the Aperture at f/8 and different ISO settings.

This shot was taken with ISO 200 which meant I had to move the shutter speed to 250 in order to get a correct exposure.  Notice how the lamp is sharp but the blades are blurred.

This shot was taken with ISO 400 and required a shutter speed of 500 to get correct exposure.  The lamp is still clear and now the blades are a bit more clear than in the previous shot.

This final shot was taken with ISO 800 and a shutter speed of 1000 to get correct exposure.  Notice how the blades are now very clear even on the moving fan.  Sorry the pics are a little dark, but it's the best thing I had to show movement nearby.

Anyway, this gives you a look into what I'm currently learning and I'm having a blast with it.  I'm attempting to learn what I can before our Disney World trip in a week...wish me luck!


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