Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE mountain ( id VARCHAR, country VARCHAR )
TABLE: CREATE TABLE photos ( camera_lens_id VARCHAR, mountain_id VARCHAR )

### Question ###
How many distinct kinds of camera lenses are used to take photos of mountains in the country 'Ethiopia'?

### Accurate SQL ###

SELECT COUNT(DISTINCT T2.camera_lens_id) FROM mountain AS T1 JOIN photos AS T2 ON T1.id = T2.mountain_id WHERE T1.country = 'Ethiopia'