That makes sense to me. Basically a 21 f/1.4 lens (as most f/1.4 would have a t~1.4). Have you seen any reviews on the optics? My only curiousity is that video lenses may not need to be as sharp as photography lenses with FHD being equivalent to 2 MP and 4 K being about an 8 MP file in 16:9 and 10 MP file normalized to 4x6 format. It isn't until 8K that you really start talking about those lenses being needed to resolve details we are used too at ~33 MP in 16:9 and 39 MP equivalent in 4x6 format. Even if you can't find a good review, if they have a good return policy, you could check it out and return if not up to your standards.

BTW, 11 aperture blades, it should have some beautiful bokeh and smooth rendering.