I'm not familiar with the Brenizer Method but this is nothing new.
I've been playing with it for several years, generally using a 300mm f/2.8 lens currently mounted on a canon 1Ds3.
Most folks will tell you that using a tripod in necessary...it's not, as CS4 does a marvelous job of
photomerging hand held images. You should however be shooting in manual mode to lock-in your settings.
And when developing you images, prior to merging them, always sync any exposure adjustments to the brightest image to avoid having the blown out whites that are present in your example.
Also, if you prefer using your 50mm, you might want to crop and use only the center of each image for the merge process.
A quick peek at page 210 of this site
http://software.canon-europe.com/fil...Book_10_EN.pdf
will explain loss of quality at the edges of your original images.
Keep on shooting my friend.
