Explorecams - Explorecams allows you to search through thousands of images that people taken on specific photo camera bodies & lenses.
Openverse - Openverse is an Openly Licensed Images and Audio database and a growing community of photographers, illustrators, and musicians who share their work under a Creative Commons license.
DxO ONE - DSLR image quality for your iPhone
Magdeleine - Magdeleine is a stock photos website offering thousands of royalty-free, high-quality photos for personal and commercial projects.
Shutterstock - Shutterstock is a provider of stock photos, illustrations, and vector art. The website allows individuals to purchase a subscription and download copyrighted art for creative projects. Read more about Shutterstock.
Smithsonian Open Access - 2.8 million high-res images for anyone to download free.