What cause white dots in the pictures from a camera?

Question

At night I've taken pictures with flash on. I'll be standing still and take about 4 - 6 pics. There again this white perfect circle in one area, next picture it moved just alittle to another area. Sometimes it larger or smaller and some disappeared. Or in a bunch at a time. What causes it to do that? It's not raining, the cam is not facing any outside light.

It's totally dark. The lens are clean and lint free. Can broken glass make perfect circle or reflect it off the ground onto brick wall or fence poles. Can be in different sizes? Can it be in a bunch? Just maybe how I holding the cam and not knowing I moved? Do digal camera have that many error ? Just got it brand new from Walmart in Jan. It's HP brand. Could it be the brand I got. It is bugging the c**p out of me . I just want to get a nice picture at night.

Answer 1

I have the same problem a lot of times... so I looked into why this happens a while ago. Of course, I cannot guarentee this is what you're seeing because I do not have an example of your photos.

This error is very common in digital photography, although I'm sure the brand does not necessarily effect this. It's the camera's exposure to light that creates defective pixels, and in your case, it seems as though your camera is experiencing hot pixels, which most commonly appear against darker backgrounds such as when you shoot in night mode or in long exposures.

You see... in digital photography, the charge-coupled device, or CCD, emits an electrical charge, and if it's exposed to heat or darkness long enough, the charge will leak and activate the pixels "to light up". Usually those pixels in cameras get heated up faster and that is why they turn white.

I would suggest testing your new camera for hot pixels (aka charge leakage that is suceptible to low light and heat). But the steps seem rather lenghthy, so perhaps before you use your camera in the dark, expose it to light so the flash can be "adjusted" to the darkness. Here's a link that might help...

http://webpages.charter.net/bbiggers/DCE...

So sorry to hear about your problem, but most new cameras have these defects. They're just too high tech. xD

-Hizumi =)