[Alex Rodriguez]

Rokinon, which is the same brand as Bowen, and Samyang, has just introduced a new line of cine primes for dslr shooters called xeen. The aperture ring is smooth and and the focus ring has a long throw. But if you want a real cheap fix to your problem you could use a variable polarizer/nd filter. It’s actually better than closing your iris because your depth of field doesn’t change.