Note:
"Royalty-free" doesn't mean the image is free. What that term indicates is that you pay a one-time fee and are able to use it for whatever means you wish. You still have to pay.
The other type of payed image is "Rights Manged". These are usually the top of the line photographs and the terms are very specific. IE, how many times it will be used, the geographic distribution (local, regional or national), the type of project it will be used for, how large it will be utilized within the design, etc.
So, a rights managed image placed in a local publication will cost less than if placed in a national magazine. Or, the image used as a feature shot will cost more than if it were a small inset.
Free
Be sure to read the conditions, as they may require photo credits. Also, some of these "free" sites pull images from other places, such as, Flickr. Terms of use will vary greatly. Always be professional and respect other creatives individuals—they are your peers.
Morguefile
FreeDigitalPhotos
everystockphoto
FreePhotosBank
FreeRange
FreeImages
Museums
Free hi-res photos from their collections.
Metropolitan Museum of Art (400,000)
The British Library (1,000,000) Public Domain
The British Museum (2,000,000+)
Los Angeles County Museum of Art (20,000)
Pay
Pricing for stock photos range from dirt cheap to astronomical. Check before you click!
iStock Photo
Shutterstock
Getty Images
Fotolia
Photographing work for your portfolio
How to Photograph Your Portfolio Work in 6 Simple Steps.
