re: #12 Rightwingconspirator

Er, no, those would be C mount and while it’s possible to use them you won’t get the kind of results you might think. If you are interesting in primes on a Canon 7D then look at the actual Canon EF primes, the new Zeiss manual focus primes or old Pentax primes. Any of those options will work far better than old C mount cinema lenses.