Water spot behind lens ?

The image sensor in the camera needs cleaning. You can buy cleaning kits, but often you'll just make the problem worse until you gain experience. Many camera shops now offer professional sensor cleaning so you might decide that it's better to pay someone else to do it for you. If you join a local camera club there's also usually at least one sensor cleaning guru who can do it really well if you buy him or her a beer.

Prevention is better than cure, so always blow dust off the camera and lenses before changing them, and never leave the camera for any length of time without either a lens or a body cap on the front.

Do the spots only occur when taking flash pictures and do the spots look like "soap bubbles" and appear in different places in each picture? If so, these are dust particles reflecting the flash back into the lens. It's a problem with all point and shoot cameras because the flash is so close to the lens.

clean the lens,get it serviced the lens as well as CCD.

The spots are dust particles in the air reflecting the flash back to the camera because the flash is so close to the lens. This is a problem with all point and shoot cameras...some more than others.

I had the same problem with mine two i ended up sending it to canon and they replace the lens unit.

Received an explanation from Canon.

You did not mention the model of your camera but I assume its a compact camera.

It happened to me once. I opened the camera, strip the cards and cleaned the lens.

But I warn you, its very annoying operation. You need shakeless hands and super focusing abilities. And also it takes time, need patience. Use mild cleaner not strong one. You may use a hand blower, this method is more simple, dont need to go through lens and strip entire cards etc. Just open the back of the camera and look for a cavity to put nozzle through to lens area and cross your fingers than blow it lightly with hoping the dust gone. :)

Yes, if you have used different lenses and a smudge still appears (in the same place) there may be something on your sensor. Have you cleaned or touched the sensor in the past? Typically sensors only get dust (shows up as small fuzzy dark spots) on the sensor, not smudges.

If you can see condensation, then please do not switch on the camera.

Let it dry off. You could mildly use a blower(hair dryer) to dry , but not very powerful.

Once the condensation is dried, then if light spot remain and does not interfere in the quality of the photgraphs, it might go away in time. But if it is bothering you. Then you better take it to the nearest Canon service center, who will open and service your camera.

Best of luck.
Let me know if you need any help. Thanks for using FixYa!

it should be a stain spot on the camera lens..try taking it to an authorised service point and have it cleaned