Hierarchy classification:

1. top of the aat hierarchies
2. Activities Facet
3. Processes and Techniques (hierarchy name)
4. [processes and techniques by specific type]
5. [image-making processes and techniques]
6. [photography and photographic processes and techniques]
7. photographic techniques
8. picture-taking techniques
9. [picture-taking techniques by radiation type]

Anotations

Scope note:

Quasi-photographic techniques to record different densities in a gas as a pattern of colored bands of light and dark; frequently used to record patterns of radiated heat; not all forms of this technique require a camera and lens.