Certs from anywhere. People who want to learn will seek out learning. People who are hiring want proof that potential candidates are hungry learners... certifications provide that proof. The hiring entity, of course, should then do their due diligence and research the certs. In the technical arena, the certs are well known... less so in this field.
Certificates of completion for seminars are perfectly acceptable examples of a "certification"/cert that would demonstrate that one is actively pursuing ones betterment. Laurels and awards on projects show efforts at choosing projects and groups that are getting work completed working on festival distribution. The cert you're looking for depends on what you want in a candidate.
Do you want to spend tons of $$$? Hire someone with a GREAT reel, a long CV, cinematography awards from prestigious festivals/groups and union membership (which is also a guarantee of employee quality from the union).
Cheaper options can have fewer of these categories met. Someone with a GREAT reel and a short CV may just not have had the number of opportunities to gather the other bits yet, so they'll be cheaper based on amount of experience.
I've done networking for >10 years, but am not certified to do so, no CCSE or CCSP. Does that mean I can't do it, nope. It means anyone hiring me is taking a gamble on the lack of the certification... to measure that, they may look at the length of time I've been doing that particular facet of my job and even call previous employers to make sure I have the skillset. The cert guarantees a minimum level of knowledge on the part of the candidate... they could still be a horrible employee, but at least they have had the exposure to the knowledge they should have.
Exposure to the knowledge is one of the primary facets when hiring someone... the other two I think are a big deal are that they are do-ers (will pursue a task without prompting) and that they are a good fit with the team. A staunch conservative christian simply won't fit if your team is comprised of highly motivated liberals with language like a sailor on leave (no offense intended to any sailors out there) wearing "Satan Loves You" t-shirts on set. They may be the best person for the particular "Look" you're going for, but would never work on that set.
You're hiring someone. Look at the process that way and the answers you seek become clearer. More experience = more $$$ & less risk... Less experience = less $$$ and more risk... less $$$ and less risk, you're running a charity that someone really loves!