Headlines, take #1

My post dated 11/11/11 referred to David Bellos's Is that a fish in your ear? (subtitled, Translation and the meaning of everything). Chapter 7 features a number of clear, succinct descriptions of well-known translation challenges.
The section on headlines says that the target-language version of a source-language headline "must conform to the general conventions of headline writing" in the target-language culture "because headline writing is just as much a genre -- a particular kind of language use restricted to particular contexts -- as promising, christening, threatening, and so forth".
French headlines and article headings typically explain quite a lot of what is to come, often at greater length than English headlines.
English headlines are often written specifically to intrigue, arouse curiosity, trigger a smile (using a pun or other play on words or language) or even be thorough enigmatic, since the point is not so much to summarise as to entice the reader to read on.
This approach can also be considered as an aspect of 'translation by emulation'.

Much the same approach applies to caption writing.

To sum up, headlines and captions should be drafted after completing the translation of a technical journalism article. The words of the source texts are a minor consideration. The aim has to be to write headlines and captions that work in their own right for the assumed or explicity defined target audience.