To convert light room RAW files to jpeg you actually have to export them to convert them. So select the photos you’d like to convert.
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Then select file. Then select export.
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In the export dialog you’ll need to select the settings you’d like here. Scroll down to the file settings section. In the drop down select jpeg.
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Select the quality and color space. Then click export. This will export these photos and turn them into jpegs.
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