When using images from the web, always try to find the highest resolution images and from the most original sources, preferably the archive currently curating the work. Take detailed citation notes as you research, and bookmark all relevant URLs.
When inserting images into your document, make sure they are:
- at a legible size and resolution–not pixillated.
- properly scaled–not stretched or squeezed.
- not cropped–unless they are labelled “detail.”
To muck up an image is like mis-quoting. Treat the images with the same respect you treat your prose sources.
Label each image fig. 1, fig. 2, etc., and refer to them parenthetically in your text. E.g.: “Douglass’s portrait for his 1855 autobiography (fig. 3) contrasts sharply with that of his 1845 one (fig. 1).”
Cite the image at the moment in your text when you first mention it. After that, there is no need to cite it again, as long as you are clear in your text when you are referring to it. Include all the following information, as relevant and as known:
- title, if it has one (this may be the poster’s caption); or portrait sitter’s name, if known; or [your brief identification of it in square brackets].
- creator/s (e.g., artist, engraver, photographter, etc.)
- medium (oil, watercolor, daguerrotype, engraving, etching, etc.)
- year of creation or original publication
- original publication information, if it was published
- archive currently holding it, including collection name &/or item number if it has one
- reprint information, if using a reprint (e.g., in an art book)
- website or database information for digital copy (including full website citation info)
For details, see Tipsheets > Chicago Citation Guide and Lipson, Cite Right.