The top Leo put around a lens (9)

I believe the answer is:

telephoto

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'lens' is the definition.
(telephoto lens is a kind of lens)

'the top leo put around a' is the wordplay.
'the top leo' can be anagrammed to 'TELEPHOTO'.
Though, I'm unsure how the anagram is indicated.

Can you help me to learn more?

(Other definitions for telephoto that I've seen before include "Distant shooter" , "Kind of lens" , "Magnifying lens in a camera" , "Sort of lens" , "Long type of camera lens" .)

I've seen this clue in The Irish Independent.

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