November 23, 2009

I was encouraged over the holiday by comments over the holiday from family about the blog. Thank you out there for those who check it out. My BiL had some questions about this picture so I thought that I would explain.

I was trying to figure out a POD during break on this day, and I saw a couple of people on bikes whiz past me and it reminded me of a technique I've been dying to try out. There were no more bicyclists, so I aimed toward the street.

With this situation, we've got the feeling of motion...of speed. But, in this case, instead of having the moving object out of focus, I've put the car in focus and all of the motionless things out of focus.

To do this, of course, you need a slow shutter speed. In this case, it was probably 1/10th to 1/20th of a second. The problem with that slow of a shutter speed is that it lets a lot of light in. In other words, you get a really bright picture. So bright that you can't see anything. To compensate for this, you need a larger aperture setting (a smaller hole for the light to come through). You also want your light sensor to absorb less light (make it slower). The light sensor sensitivity is controlled by ISO. The lower (slower) the ISO, the less light comes in. So, this ISO setting was probably about 100 or 200.

Now, I realize that this explanation doesn't mean anything to anyone, so let me explain how to do it on your camera if you've got one. (I actually was using our smaller camera because I don't carry around our big camera during the day and I haven't figured out how to adjust everything manually so this explanation can be used by anyone with a camera).

On most cameras (even the little silver ones) there is a dial with different pictures and letters. The control function that is represented by an "AV" means aperture value or aperture priority. It means that if you turn the dial to that function, you can control the aperture yourself and the camera will measure the light in the air and will automatically adjust the ISO and shutter speed that will correspond with the aperture setting you've chosen. Pretty amazing. Actually, the relatively short delay time between the moment you push the shutter release button and when the shutter actually opens is the camera's computer figuring all that out automatically!

So, if you want the shutter speed to be slower, you close the aperture (the hole that the light comes through) by increasing the number for the aperture setting. The camera will do the rest.

Another way you can go about doing this, which is not the way I did it, but is probably a more logical way would be to turn the dial on the camera to "TV" mode which stands for time value or time priority. In this case, "Time" corresponds with shutter speed (or how long the shutter stays open to expose the light sensor to the light. By the way, the light sensor is what captures what you see. It's the same thing as film in old cameras, but the digital counterpart). So, if you want a slower shutter speed, turn the dial to TV mode, set the shutter speed to a slower speed like 1/10th of a second and the camera will take care of the rest.

Now, if you want to take a picture like the one above, turn the dial to AV mode, set the aperture to a high number setting, and get ready. When the moving object comes along, point the camera in its direction, hold down the shutter button part-way to focus the camera on the moving object, then follow the object with the camera so that it stays in the view of the view finder. As the moving object passes, fully press the shutter button (take the picture).

Or, if you're going to control the shutter speed instead of the aperture, turn the dial to TV mode, set the shutter speed and follow the same procedure from there. The awesome camera will take care of the rest! Enjoy! WHew!! That was wordy!