How did Ibn Baṭṭūṭah’s work differ from al-Idrīsī’s?

Ibn Baṭṭūṭah traveled to places he wrote about, while al-Idrīsī sent explorers.
Ibn Baṭṭūṭah focused on work in mathematics, while al-Idrīsī was an astronomer.
Ibn Baṭṭūṭah became a political adviser in Sicily, while al-Idrīsī traded along the Silk Road.
Ibn Baṭṭūṭah developed the idea for the camera obscura, while al-Idrīsī explained how it worked.