Disagree, adopting American photographer's means of scattering light evenly (8)

I believe the answer is:

diffuser

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'photographer's means of scattering light evenly' is the definition.
I can't tell whether this defines the answer.

'disagree adopting american' is the wordplay.
'disagree' becomes 'differ' (synonyms).
'adopting' means one lot of letters goes inside another (inserted letters are taken on or adopted).
'american' becomes 'US' (United States).
'differ' placed around 'us' is 'DIFFUSER'.

Can you help me to learn more?

(Another definition for diffuser that I've seen is " Translucent light cover".)

I've seen this clue in The Irish Times.

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