Johann Friedrich Clemens ( 1749 - 1831 ) was a Danish painter. Johann Friedrich Clemens s works have been put up for auction numerous times, with realized prices surpassing estimated prices, varying from 39.43 USD for Den rædsomste Nat i Kiøbenhavn imellem den 4. de og 5. te septr. 1807 in 2004 to 1280.27 USD for Bataillen d. 2. April 1801, paa Kiøbenhavns Reed in 2007 , based on the size and