Is SONY good enough for Professional Photography?

The short answer: YES!

A little known fact is that Sony acquired the camera operations from Konica Minolta (after the merge of Konica and Minolta) in 2006. This technology included the professional equipment in production by Minolta at the time. Sony took this technology and built upon it to produce some outstanding camera over the last couple of years. Sony retained the Alpha/Maxxum/Dynax mounting system on their lenses and almost all of the old Minolta lenses are fully compatible with the newer Sony bodies.

It is true that currently over 80% of the professional market is dominated by Canon and Nikon cameras, but this fact alone does not make them the only professional cameras available. There are quite a number of world renowned photographers who use and have even switch to Sony. Take a look at the list of professional photographers from around the world below who use Sony cameras:

http://briansmith.com
http://www.andykatzphotography.com/
http://www.davidmclain.com/
http://www.photographybylambert.com/
http://mjs-exp.com/
http://www.merakohphotography.com/
http://www.studiotempura.com/
http://www.don-k-blogsite.com/
http://www.karenengelphotography.com
http://www.kristencaldwellphotography.com/
http://www.photomargaret.com/
http://www.nigelbarker.tv
http://www.cristinamittermeier.com/

The list could go on … but I would suggest you refer to Google for more professional photographers using Sony camera.