Samsung SDP-6500 User Manual page 36

Adjusting your image with GUI
NEGA Effect
Allow to switch for negative / positive image (default : positive). Click [NEGA Effect] menu with the left mouse
button, current image turns negative image and menu turns checked state. To return positive image, click
[NEGA Effect] menu again (and then menu turns unchecked state).
Aperture
Allow to control the sharpness of the output image (default : On) Click [Aperture] menu with the left mouse
button to turn on/off aperture mode. (Image mode / Text mode)
Video Out
Allow to switches video output mode to NTSC or PAL.
Click [NTSC/PAL] menu with the left mouse button, video mode is switched to current value.