Gear custom post types. I want to be able to relate multiple 'gear' posts under a 'photographer' and then also be able to point to the related 'photographers' under a gear page.
WordPress by itself doesn't provide a built-in way to handle
many-to-many relationships, you have two general ways of creating such relationship:
Using a plugin
The best plugin for this purpose is
Posts 2 Posts by Scribuwhich is not maintained currently, but It's bug-less and won't introduce any problems in a long shot. But please be aware that this plugin requires some coding to get it up and ready and has to be active to work.
Coding it yourself
I'm not against the above plugin but, If you're not going to have only one relationship of this type then, I highly recommend you to develop a basic
many-to-manyrelationship for it. The only reason for this is the age of plugin and its small community.