Photoshop’s “Photomerge” command
I own RealViz Stitcher, having paid an inordinate sum initially, and over the years to upgrade it. But in tandem with built-in Camera Raw, Photoshop CS3’s command works quite well. The 30-megapixel image below was created in seconds using it.
Photomerge apparently uses a fairly sophisticated means of merging the photos. The result is a layered and masked file. The uneven (and therefore likely better) “join” can be seen below:
One of the merged layers, hidden, to reveal the “join” pattern