Mysterious CIrcles

[Boozabazoo]

Hi, I have a friend who has a Nikon Cool pix and she is having problems with mysterious circles when she takes flash pictures. Can anyone tell me what is causing this and how to cure it. A sample pic is enclosed.

Thanks!

[Lemming51]

Caused by dust/flare on the digital sensor and/or lens.
Or ... they are supernatural beings called "orbs". ;-)
http://theshadowlands.net/ghost/orbs.htm

[another view]

I think there's a good chance that it's just a dirty lens. It might not show up in every shot, but should be in the same place when it does show up.

Coolpix cameras and other compact digitals are sealed so it's pretty unlikely that the dust is directly on the sensor - this is a problem with DSLR's though. I usually just use a microfiber cloth designed for cleaning lenses, maybe blow on it first to get the loose stuff off. Any camera store should have one.

[Lara]

Hmm, now I have a question guys. Would dust have a distinct pattern?

[another view]

On a lens, it could look like that. Possibly there's some light reflecting off something that's making it show up more (but I don't see that in the shot above). Dust shows up on sunrise/sunset shots because of the backlighting of the sun itself - it makes the dust glow on the lens element. I think this might be a similar thing. I have a shot (35mm slide) that I took of a sailboat race that has a spot like that - lots of reflections going on between all the surfaces of the boat and the water itself, not exactly sure what it is but probably the same thing.

With a compact digital camera like a Coolpix, the focal length is really short - like 7-20mm or something like that. The shorter the focal length, the more depth of field you will have with the same aperture (a few other factors count too, but in real-life shooting, this is all you really need to worry about in most cases). Because of this, something on the lens might show up as a distinct object even though it's so close to the sensor. More likely than a 200mm lens at f2.8 at 10' anyway!

Now on a DSLR, when you get dust on the sensor you'll see a small darker spot on the image. You can see right thru it though. I think that's because it's so close (on the glass filter sitting right on the sensor) and so out of focus that it shows up like that.

[Lara]

Thanks for the info Steve. Interesting that a speck of dirt or dust could create such a pattern.

[Liz]

Now, this is interesting. And we throw dust away.

Have a nice weekend, Lara!

Liz

Thanks for the info Steve. Interesting that a speck of dirt or dust could create such a pattern.