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 table_272313_1 ( aspect_ratio VARCHAR, vertical VARCHAR, pixel_aspect_ratio VARCHAR )

### Question ###
What was the aspect ratio if the vertical pixel is 480 and pixel aspect ratio is 1:1?

### Accurate SQL ###

SELECT aspect_ratio FROM table_272313_1 WHERE vertical = 480 AND pixel_aspect_ratio = "1:1"