Yes! Any of the adapters can be used to shoot video. In fact one of the first tests I shot was this slow motion footage - shot on the cardboard prototype of the Polaroid Land Camera adapter and an iPhone 6 - so your results will likely be better than this!
So, the short answer is yes. But there are some caveats…
- Dust - the focussing screen inside all ObscuraFlex™ adapters is a physical membrane, so dust, scratches (and possibly the slight texture of the screen itself) may show up in the footage. It shouldn’t be too much of an issue in HD, but video shot at 4k and watched on a large screen might start to notice “stuff on the lens” which may be undesirable.
- Exposure - the ObscuraFlex™ system requires a fair amount of light, and even with a wide open lens, it’s probably going to be a “daylight only” kind of solution.
- Image Rotation - the image inside the camera will be rotated upside down - which doesn’t seem like a big deal until you try to follow a moving subject. The free app Blackmagic Cam has a "Flip Image for SLR Lens" feature that addresses this by rotating the image 180º.
- Framing and Stabilization - most smartphones have built-in image stabilization that can become quite noticeable when shooting with ObscuraFlex. Dust on the focusing screen will move around as the phone digitally shifts the image to keep everything feeling smooth. So you may want to turn off stabilization completely. And depending on your setup you may have to zoom in a little, and crop carefully.
- Focus Breathing - all stills lenses “breathe” when you adjust focus, this is a phenomenon that motion picture and video lenses go to extreme lengths to eliminate with complex mechanical systems that compensate precisely for the zooming effect a lens exhibits as it moves back and forth. This effect will be quite noticeable as you adjust focus.
That said, as a filmmaker myself I am very excited by the video possibilities of the ObscuraFlex™ system and would not hesitate to shoot with it on the right project.