The Chicago Manual of Style recommends that images are cited differently depending on the source from which the images originated. This guide pertains particularly to still images relating to television content.
The HWS community has online access to the 17th edition of the Chicago Manual of Style.
This scenario applies to original works of art. In the case of television programs, photographs taken behind the scenes would fit into this category, as would location photographs and other works that are clearly not stills of the show itself.
To cite an image extracted from a larger work, see 14.158.
This scenario applies to published works, i.e., books and journal articles, containing images. In this instance, images are extracted from another, larger, body of work. The citation is chiefly back to the work itself, either book or article.
This scenario would particularly lend itself to still images from a show that are taken from or referenced in another work.
DeCandido, GraceAnne A. "Bibliographic Good vs. Evil in Buffy the Vampire Slayer." American Libraries 30, no. 8
(September 1999): 44-47. https://www.jstor.org/stable/25637287
Cohen, Nicole, and Andrew Jones. "20 Years Ago, 'Buffy' Welcomed Us All to the Hellmouth (aka High School)." NPR.org,
March 10, 2017. https://www.npr.org/2017/03/10/519465836/20-years-ago-buffy-welcomed-us-all-to-the-hellmouth-aka-high-school.
You may find yourself wishing to extract a still image from a moving image resource, in which case this librarian would recommend you cite the original moving image, similar to scenario 2 (above).
When working with these types of online media, Chicago prescribes:
Note also: if the source is a recording of an earlier event, include information about that earlier event.
Television Academy. "True Blood Cast Shares a Vampire Pun at the Emmys | Television Academy Throwback." Filmed
August 2010 at the 62nd Emmy Awards. YouTube video, 0:49. Oct. 27, 2020. https://www.youtube.com/watch?v=l5DSrItKonA
Note: The above example is a "Throwback" video whereupon it was posted to YouTube 10 years after its original broadcast. The information about the original broadcast (62nd Emmy Awards) was extracted from the notes accompanying the posting.