To change default settings in lightroom while you’re under the develop tab click on the reset button at the bottom right of the right hand tool bar.
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This will reset all settings.
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Next make the adjustments how you’d like them to be.
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When you’re satisfied hold down option on a mac, or alt on a pc and the reset button will become a Set as default button. Click the button. The settings will now be saved as default settings.
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