CREATE TABLE photos (id DECIMAL, camera_lens_id DECIMAL, mountain_id DECIMAL, color TEXT, name TEXT)
CREATE TABLE camera_lens (id DECIMAL, brand TEXT, name TEXT, focal_length_mm DECIMAL, max_aperture DECIMAL)
CREATE TABLE mountain (id DECIMAL, name TEXT, height DECIMAL, prominence DECIMAL, range TEXT, country TEXT)

What are the names of the cameras that have taken picture of the most mountains?
SELECT T2.name FROM photos AS T1 JOIN camera_lens AS T2 ON T1.camera_lens_id = T2.id GROUP BY T2.id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "T2"."name" FROM "photos" AS "T1" JOIN "camera_lens" AS "T2" ON "T1"."camera_lens_id" = "T2"."id" GROUP BY "T2"."id" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1