While I see many people switching over to the Panasonic GH4 and Sony A7 series cameras (like the A7sII/A7RII), there's one product that I wanted to remind people about - the FotoDiox ND Throttle. When shooting with Sony cameras, especially in SLOG, the minimum ISO could be anywhere from 1600-3200. SLOG is such a great option to have, but means you really have to deal with ND Filters to keep a wide aperture and proper shutter speed.
The easiest and most simple solution that I know of is the FotoDiox ND Throttle. The FotoDiox ND Throttle is a variable ND Filter built right into a lens adapter, and allows you to dial in your exposure without changing your ISO, Shutter, and Aperture. Of course this only works if you are adapting a Full Frame lens to the Sony or Panasonic, and not using a native lens.
It doesn't matter if you're working with a Canon EF autofocus lens, a manual Rokinon Lens, or even high end Cinema Prime Lenses like the
XEEN, Canon CN-E, Zeiss CP.2, etc. The FotoDiox ND Throttle is one simple adapter that I highly suggest all Sony A7 series or GH4 shooters look into and find the time to try it out. Even if you're not using it all the time, I think you'll find it's worth keeping in the gear bag.
FotoDiox ND Throttle Variable ND Filter + Lens Adapter
So while I think Canon L lenses offer great image quality, you can get a (4) piece Rokinon Cine DS Lens Bundle Set for about the price of one Canon L Lens. The DS line from Rokinon are designed to be color matched, same exposure ranges, common focus and iris gear positions, a de-clicked aperture, etc. For me personally I feel they are better for video than standard Autofocus Photo Lenses (image quality aside). If you're looking into a set of Rokinon Cine lenses, I highly suggest starting with the 'Cine DS' line for the reasons stated above.
The image quality is great, and I think you'll really appreciate the longer focus (pull) throw, and de-clicked aperture which lets you set F-stops in smaller increments than you can with auto focus lenses. The built in gear ring is great for follow focuses, and the standard positions make it easier to swap lenses without moving your FF around each time.
Rokinon Cine DS Lens Bundle for Canon EF Mount
Now if you really want to step it up a bit, the Rokinon XEEN Cinema Prime lenses have a standard physical size, lens diameter, better optics, less breathing, etc. To date they are probably the most affordable Cinema Prime Lenses that cover a full frame sensor. They have a 114mm Diameter which is exactly the same as a Canon CN-E Prime, or Zeiss CP.2. You can find great deals on XEEN Lens Sets via eBay (click here).