Camera Sensitivity ISO, Custom White Balance

Calibration display

RECORDING MODE

CUSTOM WHITE BALANCE

Custom-white-balance function allows a photographer to calibrate the camera to a specific lighting condition. The setting can be used repeatedly until reset. Custom white balance is especially useful with mixed-lighting conditions or when critical control over color is needed.

To calibrate the camera, press the function button and turn the

control dial until the custom white-balance icon and “SET” appear on the data panel and red on the monitors. Select a white object and fill the image area with it; the object does not need to be in

focus. Press the shutter-release button to calibrate the camera. If an error occurs during calibration, an error message will appear on the monitors. Press the controller to cancel the message, then

recalibrate using a suitable reference target and the shutter-release button. This sequence can be repeated as many times as necessary.

The setting will remain until another calibration is made. If the custom white-balance setting needs to be used again, while pressing the function button, turn the control dial until the custom white-balance icon is displayed without the “SET” on the data panel and white on the monitors. The camera will use the last custom setting.

The built-in flash can be used with the custom setting. However, since the flash is daylight balanced, it will give an unusual color cast to an image if the camera is calibrated to any other light source.

Shooting tips

When making the calibration, the color of the object used is critical. The object should be white. A colored object will cause the calibration to compensate for the object color rather than the color temperature of the ambient light. A blank piece of white paper is an ideal surface and can easily be carried in a camera bag.

CAMERA SENSITIVITY - ISO

Five settings can be selected for camera sensitivity: Auto, 100, 200, 400, and 800; the numerical values are based on an ISO equivalent. ISO is the standard used to indicate film sensitivity: the higher the number, the more sensitive the film. See setting the function dial section on page 40 to change the ISO setting.

The auto setting automatically adjusts the camera sensitivity to the light conditions between ISO 100 and 400. When the flash is activated and camera sensitivity is set to auto, the ISO value is set to ISO 200. When any other setting than auto is used, “ISO” will appear on the data panel, and “ISO” and the set value will be displayed on the monitors.

Photographers can select a specific sensitivity setting. Like grain in silver-halide film that increases with speed, noise increases with sensitivity in digital imaging; an ISO setting of 100 will have the least noise and 800 will have the most noise. A change in ISO also affects the flash range (p. 79); the higher the ISO, the greater the range.

As the ISO value doubles, the camera sensitivity doubles; changing the ISO between 100 and 200, 200 and 400, or 400 and 800 changes the camera sensitivity by one stop or 1 Ev (p. 36). A change between 100 and 800 changes the camera sensitivity by a factor of 8 or three stops. High ISO settings (400, 800) will allow the photographer to hand hold the camera in low-light conditions without the need of a flash.

Camera Notes

When making bulb exposures (p. 92), noise can be more pronounced because of the unusual- ly long exposure times, especially at 400 and 800 ISO. When making long bulb exposures of 20 to 30 seconds, a camera sensitivity setting of 100 or 200 will produce excellent results. At high- er ISO settings, using shorter exposure times (8 - 16 seconds) will reduce the effect of noise. With long exposures at high ISO settings, noise from interference may be noticeable.