To export to facebook lightroom 4, you must first go to the Publish Services panel on the left side of the Library module,
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Click the Facebook connection Set Up button.
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In the Lightroom Publishing Manager dialog box, look under Facebook Account and click Authorize On Facebook.
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Follow the prompts to allow Facebook to communicate with Lightroom.
To create a collection of photos to export to Facebook, right-click and choose Create Collection (A collection of any photos you choose)
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Give the collection a Name, indicate if you want to include selected photos, and choose or create a Facebook album to upload to.
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Or Create Smart Collection (A collection of photos based on rules you define).
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Give the smart collection a Name and choose or create a Facebook album to upload to.
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