Here:
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Interestingly, the designer says that his original tricorder design was close to the size of the TOS prop, but the producers decided it was too bulky for the characters to carry through some of the movie's planned action scenes.
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I think it would be too easy to assume that a prop would never change. It wouldn’t be a challenge for the filmmakers or the fans if nothing ever changed. What comes with the change is speculation, possible ridicule and potential praise - but never in that order and never all three simultaneously. My goal, whether good, bad, or indifferent, is to give the public something to talk about.
Interestingly, the designer says that his original tricorder design was close to the size of the TOS prop, but the producers decided it was too bulky for the characters to carry through some of the movie's planned action scenes.