The most common and most likely answer to this crossword clue is the 12 letter word TRANSPARENCY
I've seen this crossword clue in The Times
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More clues leading to the result TRANSPARENCY
Buddy explains!
The straight part
We know that "Openness/familiar to photographers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case openness/familiar to photographers = transparency.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TRANSPARENCY mean?
TRANSPARENCY noun- The quality of being transparent; transparence.
- Openness; accessibility to scrutiny.
- A translucent film-like material with an image imprinted on it, viewable by shining light through it.
- A transparent object.
- Sufficient accuracy to make the compressed result perceptually indistinguishable from the uncompressed input.