Is there an option or way to have Aperture convert RAW or large TIFF images to JPEG prior to uploading to an iPad via Photostream?
You mean, uploading to Photo Stream from Aperture?
If you have Aperture set to automatic upload, then you have no control over the upload format.
But if turn off automatic upload and drag your images manually to the Photo Stream, Aperture will only upload jpegs.
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