The HolyManta VND camera adapter revives the tradition of easily accessible ND filters popularized by ENG and production digital cameras that seem to have fallen out of style with the introduction of DSLR and many large format cameras.
Currently the HolyManta offers a way to attach EF lenses to your Micro-Four-Thirds (MFT) and Sony NEX mount cameras. The variable ND filter offers 0 (with the filter retracted) to 10 stops of light reduction all easily controlled "never requiring you to take your eyes off the viewfinder."
An added benefit of putting the ND filter between the lens and camera comes from leaving the ND filter down when you swap lenses. The filter acts as a dust cover, protecting your sensor from dust and particulates that might scratch it.
Holy Manta is another example of a product developed with the aid of crowd-funding. In this case creator Thomas Läräng chose the European based service FundByMe. After flushing out the design and a fully functional prototype Thomas took the Manta to the public and raised $13,150 which set production in motion.
The Holy Manta comes physically in two parts: the adapter piece which mounts the lens to the camera and a separate ND filter unit which mounts between the lens and camera. The filter unit is held in place by two magnetic contact points and fits with a snug click.
To use the ND filter you just have to pull up on a mechanical lever and the ND element snaps into place. With the ND in place, a cogged wheel appears which controls the density of filter.
When you're finished shooting, the filter unit can remain on the camera and protected with a separately purchased body cap or quickly removed via a tiny metal eject pin.
The filter adapter feels almost invisible, and feels very much like a natural extension of the lens. The construction feels solid and professional. I felt comfortable hanging a large 35mm Rokinon on the front of my Panasonic GH2, and had no operational issues working in the field.
The ND filter controls are smooth and represent clever engineering. I was impressed by the transitioning between ND elements. I initially assumed that changing the filter density would be visually too abrupt to completely replace a smooth aperture ring, but to my complete surprise I found the transition to be smooth and in fact easier on the eye than most of my lens's built in iris.
The only drawback I encountered was the fact that the current version of the Holy Manta is a "cold" adapter, meaning that while using the mount the camera will not be able to communicate with the lens. The thinking behind the current version is that either your lens will have a manual aperture ring on the barrel or that you'll be shooting wide open and use the ND filter to control exposure. While there has been no announcement regarding a "hot-shoe" version (meaning, a version of the adapter which allows for communication between the lens and the camera), Thomas hinted at the possibility that one might be developed.
If your lenses have manual iris rings, the Manta is a great alternative to having ND filters attached to the front of your lens. You can quickly swap lenses without having to fiddle with additional filters or removing matte boxes.
The HolyManta is very usable without a manual iris (in fact it's what Thomas had originally intended it for). To use the Manta in this fashion you first will need to set the iris of your lens by mounting it to your camera without the adapter and opening it to the most open aperture. The beauty of the Manta is the smoothness with which the filter changes densities: this allows it to act as a sometimes superior replacement to the lens's own iris.
If there is still too much light (or you want a wider depth of field), you can pop the lens back on without the adapter, close down the aperture, and shoot with the ND filter.
Example footage using the filter can be seen in Thomas's FundByMe pitch video and other samples: (which can be found here>>) [www.holymanta.com/pages/media]
The Holy Manta lens adapter kit retails for $315 USD, while additional mounts and ND units can be purchased for around $95 to $315. Visit www.holymanta.com for more ordering information.