Digital Image Analysis and Camera Settings

Dr. Karcher explained some of the camera technology to me this week for me to better understand the camera settings. The F-stop or Shutter speed basically is a number that determines how long the camera is open or exposed to light. (1/80 would be 1/80 seconds). If you were taking pictures of something in motion, you would need to have a very small number to avoid blurriness of the object in motion. The aperture is the diameter opening of the camera in millimeters. The larger the aperture, the more light will be let into the camera. Both of these factors seem to be determining the amount of light allowed to be exposed to the camera during the picture. The ISO was an important term when using regular film, but Dr. Karcher did not know the true difference in ISO's on digital cameras. Higher ISO film was designed for higher quality pictures.

Dr. Karcher explained this information to me because I needed to find the most appropriate settings for the new camera combined with new LED lit light box. The first step was to set up a custom white balance. I placed a grey card (colorless object) under the light box with the camera attached. The grey card had a blue coloration to it, but once you push the menu button in the custom white balance setting, the camera corrects for the lighting and you see a grey card.

Once we had gotten the white balance adjusted for the LED lights, I took some pictures with the light box on the green using the "P" setting on the camera with the custom white balance I had just saved. This camera option basically takes pictures with what the camera feels are the most appropriate F-stop, aperture, and ISO, which you can view following the picture. The most common settings that come up under those conditions were selected as the most appropriate and saved to the camera.

This was an interesting lesson. The pictures taken with the settings selected by the camera with the new white balance setting were extremely clear and really different from the original images I collected. This was a great learning experience to determine the process of selecting the correct camera settings for different situations in DIA.