With the common use of the digital camera comes the end of the polaroid camera. I'm 100% sold on the digital camera, but there is one use for the polaroid that some may have never thought to exploit. Dowsing with a polaroid is a little known treasure hunting technique.
If you don't have one of these cameras laying around they are easy to find. You can find them on Ebay, flea markets, thrift stores, and garage sales. The hard part is finding film these days. To try this you will need a uv filter and sx70 film.
It seems that buried gold creates a magnetic change in the earth and thus creates a shaft of light that will appear in the picture. If you have an area that you suspect has hidden treasure the best time to take pictures a half hour after sunrise or a half hour before sunset. I've been told that a foggy day is a good time as well.
Does this work? All I will say is I have a friend that had taken pictures of an area that he wasn't treasure hunting in and one picture had a shaft of light. He went back to the area in which the picture was taken and sure enough there were treasure signs that he had overlooked.
If you want to read more about this Louis Matacia has written several books that covers this and much more. Finding Treasure Auras and Finding Treasure Combining Science and Parapsychology are the titles.