Could someone please explain why I am getting white, semi-transparent dots for night photography with flash on?
Original image here.
Fingerprints on the front lens (especially of a point and shoot) look exactly like this photo. The light from the flash bouncing back from the perimeter of the lens at high angles will emphasize them. You are not actually seeing the oil from the print itself, you are seeing the high angle light refracted by the shape of the oil on top of the lens. Since this light is grossly out of focus, the points look larger due to bokeh. The brighter the light, the larger the "spot".