Photo-based Blog with Two Different Post Types

I’m working on a theme for a photo-based blog. The catch is that I want to make written blog posts with photos, not just photo posts with short captions. However when you click on a photo I want it to open the photo on its own page, so therefore will it also need to be its own post as well? If so, the photo posts would need to be formatted differently than the main blog posts, but I don’t know how to force them to open in this different template instead of the single.php that I already have for regular posts. I’m thinking an if else statement that filters out a category, but I can see that getting messy since it couldn’t be done by simply changing the class of the content div or anything like that.

I’ve seen a few photo-based blogs, but none yet that look like they do what I want.

I’m working on this with wamp so unfortunately I can’t give a link.