TREKCORE > VOY > EPISODES > THE SWARM > Behind the Scenes

	Robert Picardo provides his own opera singing for this and many future episodes e.g. "Tinker Tenor Doctor Spy" and "Renaissance", but does not do so in "Virtuoso" for Tincoo's hologram.
	By this time, especially following the experience in "Deadlock", the show's special effects team were seasoned in producing scenes in which Robert Picardo appears twice (as the Doctor and as the diagnostician hologram) (they did of course have practice in earlier Star Trek). Several scenes were done using a stand-in who looks very similar to Picardo when filmed from the back, with only part of him showing. That reduced the number of special effects required.
	From Janet's Star Trek Voyager Website