I think 撮る is a godan verb, so its potential form is 撮れる and its passive form is 撮られる.
In short about godan verb, potential forms and a passive forms are different.
The problem is about the ichidan verbs(+来る).
I guess a passive form and a potential form of ichidan verb are the same.
In addition to, this form is also honorific form.
(sorry I'm not familiar with Japanese grammar.)
If so, it's difficult to distinguish usage whether it's a potential form or not.
So nowadays, we remove ら from a potential form of ichidan verbs.
There is no clear criteria.
Even we have been distinguishing those from only the context.
This is extremely exceptional problem grammatically, so when you use these verbs, I recommend to use formal potential verbs until you get used to using these verbs.
I guess I made a lot of mistakes grammatically, if so, please point it out for feel free to make it easy to understand.https://www.nihongo-c.jp/blog/blog-entry-139.html