Search Engine Rankings when going from Pages to Posts

I am rebuilding a website for someone is has some pages ranked for keyphrases about the location they provide services in. It looks like whoever built this site only had search engines in mind, and not real people. When you click photography NY in the header - it takes you to a page where it talks about why photography is great with a few sprinkles of the phrase photography NY. All text, no photos...

To clean up the site for UX, I am thinking about taking the pages and making them into blog posts (it's a WordPress site).

Will this have a great effect on SEO with rankings for search engines?

Thanks for any help.