When you've exhausted the can into the pipe, back off to a nice distance and let it do its thing.The butane moves down the pipe, extracting the cannabis as it goes. When it gets to the bottom (~30 seconds after dispensing), it begins to drain into the receiving vessel. Notice the pale, glowing yellow-green-gold hue of the extract. It is obvious no chlorophyll was pulled out of the herb.
Over approximately five to eight minutes, the butane extract will finish draining from the pipe to the receiving semillas marihuana. Maintain caution with the pipe, however, since there is a lot of residual butane still evaporating from within the pipe (notice the stream of fumes coming from the top hole).