Many photos of rocks, minerals, fossils, landforms and so on can be found on the web. Not so many are free to use. You can always write to the owner of the image and ask permission to use it for your specific purpose. But often there's no time to go through all that. Here are some of my favorite places to find geology-related photos that are offered by their owners for all uses, no permission required. If you poke around the About.com Geology site, you will find examples that I've used from all of these sources.
I am not talking about "fair use," which means the copying or quoting of small portions of someone else's work for purposes of education, commentary, parody and so on. This page is about finding pictures to use yourself for whatever purposes you like.
Really free photos come in two ways: copyright-free and Creative Commons licensed.
The U.S. government is unusual in that most of its images are copyright-free, or in the public domain. They're the property of all Americans, and most of the time you can just grab them and do whatever you want. Make sure that the image you want belongs to a federal agency, though: state and local governments do NOT necessarily have the same policies.
The U.S. Geological Survey is the foremost science agency involved with rocks, landforms, fossils and resources. Its multimedia gallery at gallery.usgs.gov has thousands of things to choose from. Don't overlook the list of additional photo collections on the right-hand side.
The National Park Service is another good source. Start with the Search box on the NPS home page.
NOAA, the National Oceanic and Atmospheric Administration, has a huge image collection at photolib.noaa.gov devoted to the coasts, the sea, the atmosphere and space.
Creative Commons Photos
The Creative Commons license is a great invention that enables people to offer their work to the world on their own terms without losing their copyright. About.com Blogging Guide Susan Gunelius explains the basics of Creative Commons for the purposes of bloggers and other users. For the most freedom in using Creative Commons photos, look for images with the Attribution license. That allows anyone to edit and reproduce the photo for any purpose, as long as the photo's owner is credited.
Wikipedia is a popular source of this kind of imagery, specifically through Wikimedia Commons.
The photo sharing service Flickr also makes a lot of Creative Commons licensed photos available. The key there is to do a search first, then click the Advanced Search options and repeat the search with the appropriate Creative Commons options checked.
Let's CC is an easy-to-use site that does an amalgamated search for everythingphotos, videos, documents and sound fileswith Creative Commons licenses.
Press Releases and Newsroom Photos
Very often a scientific news story will be accompanied by press releases from the institutions that are involved. These have photos that are meant to be used by media outlets. If one of them interests you, check to see the guidelines for using it. Generally, all the institution wants is a simple acknowledgment of the photo's source. Look for them on the institutional home page under tabs like Newsroom, Media or Press.
If you make it your business to follow the science-related news, I have more sources and advice in my Geology News Sources category.
Take Your Own Pictures
Don't discount yourself. With only a little care, you can take photos good enough for the web with a basic point-and-shoot camera or even a high-end smartphone camera. You will need to use photo-editing software to prepare your images, if only to shrink them to a web-friendly size.
The advantage of rolling your own is that you will never stop training your eye and improving your skills. You can meet your own exact need better than a long search through other people's photos that don't quite do it for you. You'll also gain a better appreciation for the people who do photography at the professional level. Pro photographers add value that becomes more apparent as your eyes learn to see it.
I've gathered a few of my favorite tips for taking geological photos.
Are Stock Photos Free?
Stock photo agencies are companies with huge amounts of imagery that is offered "royalty free." That does not mean free. It means that when you buy the photo, the one price covers everything and that neither the photographer nor the agency will charge a royalty, that is, a fee that grows with the number of times you use the image. Stock photos are inexpensive, less than a dollar apiece if you use a lot of them. And some stock sites offer some free photos, as in really free. Stock photos are well made, but they tend to be generic and uninformative: if you just want a picture of a mountain, you can get a very pretty one. If you want a picture of smiling students holding up rocks, go for it. (About.com Advertising Guide Paul Suggett explains why the pros use stock photos only occasionally.) Look below for links to other articles on About.com with good advice on stock photos.
Ask the Owner
As I said at the top, you can always ask the owner of a photo for permission to use it. If you do so, remember that the owner OWNS the photo and has every right to say no, or not even reply. The best way to approach the owner is to be brief, clear and polite. Give enough detail about yourself and your intended purpose to help the owner reach a decision, but not too much information.
If the owner says yes, follow the owner's instructions completely. If the owner says no, don't try to argue. If your request is brief, clear and polite, there's no reason to take rejection personally.
People ask me for permission to use my photos. It's happened enough times over the years that I have written down my guidelines in my fair-use policy.