What are the various categories of images and what's the difference between each? (Courtesy of Mary Lee Eggart, Louisiana State University http://www.ga.lsu.edu/Effective%20Poster%20Design%20for%20Academic%20Conferences.pdf)
--Public Domain Images
(Usually a work enters the public domain 70 years after the death of creator—but there are exceptions. Some creators designate works to be in the public domain during their lifetime.)
--Creative Commons Images
permit reproduction as long as proper attribution is given.
(Available through Flickr, free stock photos archives)
--Royalty/Subscription Images
provide high quality images for a single image fee or membership--expensive!
(iStockphoto, Jupiter Images, Getty Images)
--Copyright Protected Images
can be used under the fair use doctrine for educational purposes including as part of a display or presentation at professional symposia. Proper attribution should be given.
The following websites contain images or image searches that allow you to obtain copyright-free images that can be used for your posters:
Google Images (use the "usage rights" filter)
A little guide to the use of the Creative Commons and licenses you may encounter... (courtesy of Flickr: Creative Commons http://www.flickr.com/creativecommons/):
Attribution means: You let others copy, distribute, display, and perform your copyrighted work - and derivative works based upon it - but only if they give you credit.
Noncommercial means: You let others copy, distribute, display, and perform your work - and derivative works based upon it - but for noncommercial purposes only.
No Derivative Works means: You let others copy, distribute, display, and perform only verbatim copies of your work, not derivative works based upon it.
Share Alike means: You allow others to distribute derivative works only under a license identical to the license that governs your work.
For an additional listing of image search sites and information on images, please see:
Harvard Law School Library: Finding Creative Commons and Public Domain Images