What is the maximum aperture of the lens(es) with a focal length of 20mm?
CREATE TABLE table_name_77 (max_aperture VARCHAR, focal_length VARCHAR)
SELECT max_aperture FROM table_name_77 WHERE focal_length = "20mm"
### Context: CREATE TABLE table_name_77 (max_aperture VARCHAR, focal_length VARCHAR) ### Question: What is the maximum aperture of the lens(es) with a focal length of 20mm? ### Answer: SELECT max_aperture FROM table_name_77 WHERE focal_length = "20mm"