How can I set my digital camera to 300 dpi?
You can’t and there is no need to. 300dpi or dots per inch refers to a print spec and it’s a bit strange the a photo contest would require it. A minimum specific resolution would make more sense. How large are the prints going to be? They might require that there be at least 300ppi or pixels per inch, but you’d need a print size, and the resolution of your camera to figure this out. For example, if you were going to print up to 8×10 inches, a 12 megapixel camera has about 4200 pixels on the 10 inch side, that would leave you will 420 pixels per inch (ppi) well above the 300 ppi requirement. If for some reason you need to file so ‘show’ 300 dpi, you’ll need to do that in software, but not all photo software will do this. Photoshop and photoshop elements will do this. You might have to ask someone else for help if 300dpi needs to show up on the file.