Nikon D7500 Reference Manual - English - Page 139

2 Frame a featureless white object in the viewfinder. With the lens about ten centimeters (four inches) from a welllit, featureless white object, frame the object so that it fills the viewfinder and then press the shutter-release button halfway. In autofocus mode, focus will automatically be set to infinity; in manual focus mode, set focus to infinity manually. 3 Acquire dust off reference data. Press the shutter-release button the rest of the way down to acquire Image Dust Off reference data. The monitor turns off when the shutter-release button is pressed. If the reference object is too bright or too dark, the camera may be unable to acquire Image Dust Off reference data and a message will be displayed. Choose another reference object and repeat the process from Step 1. D Image Sensor Cleaning Dust off reference data recorded before image sensor cleaning is performed can not be used with photographs taken after image sensor cleaning is performed. Select Clean sensor and then start only if the dust off reference data will not be used with existing photographs. A Image Dust Off Reference Data The same reference data can be used for photographs taken with different lenses or at different apertures. Reference images can not be viewed using computer imaging software. A grid pattern is displayed when reference images are viewed on the camera. Menu Guide 139