Great answer Dennis!
I think a good way to look at it is that if Google sees a blog post and is ranking it well for some search related to photography - they think you are knowledgeable & trustworthy. If they think you are knowledgeable and trust worthy about photography in general, they will assume you are knowledgeable and trustworthy about photography on a local level and reward you as such.
Dennis mentioned some steps you need to take to ensure that Google knows you desire those local SERPS - address citations being the most important. As Dennis also alluded to, there are other steps which you need to take as well to optimize your results, but a blog is a great start.