Canon EOS Rebel T6i EF-S 18-55mm IS STM Lens Kit Instruction Manual - Page 149

d: Program AE Shooting Tips  Change the ISO speed. Use the built-in flash. To match the subject and ambient lighting level, you can change the ISO speed (p.122) or use the built-in flash (p.166). In the mode, the built-in flash will not fire automatically. Therefore, press the (flash) button to raise the built-in flash when indoors or shooting in low light.  Change the program using Program shift. After pressing the shutter button halfway, turn the dial to change the shutter speed and aperture setting combination (program). Program shift is canceled automatically after the picture is taken. Program shift is not possible with flash.  If the "30"" shutter speed and the lowest f/number blink, it indicates underexposure. Increase the ISO speed or use flash.  If the "4000" shutter speed and the highest f/number blink, it indicates overexposure. Decrease the ISO speed. Differences Between and (Scene Intelligent Auto) In the mode, many functions, such as the AF operation and metering mode, are set automatically to prevent spoiled shots. The functions you can set are limited. With mode, only the shutter speed and aperture are set automatically. You can freely set the AF operation, metering mode, and other functions (p.354). 149