These have image circles that fit into 4:3 formats on Gopros. If you want to shoot full 180 circles on 16:9 Gopro formats you need a shorter fl or wider coverage. Lenses with shorter fl (eg. some Sunex lenses) often will not work as they cant get close enough to the sensor. Or you could use say the Entaniya 250 degree lens which has full 180 circle coverage on 16:9. This is the 250 degree lens I think --unwrapped -- https://vimeo.com/134291884 -- great flare resistance http://www.entapano.com/en/l/index.html
