This WonderPana FreeArc XL Core Unit from FotodioX is designed to specifically fit the Sigma 14mm f/1.8 DG HSM Art lens, as well as a separately available WonderPana 8.0" Holder Bracket. Those items can be combined to allow for the convenient use of two 2.0mm thick filters measuring 7.9" wide, or one 2.0mm thick filter measuring 7.9" wide, along with one FotodioX 186mm round filter behind it. A compatible 186mm inner-pinch lens cap for 186mm FotodioX round filters is also provided.





The included WonderPana FreeArc XL Core Unit consists of a compression front filter ring. Use of the WonderPana 8.0" Holder Bracket is easily accomplished by attaching its two assembly pieces to opposite sides of the FreeArc XL Core Unit using six of that holder bracket's eight included brass short-screws. Pre-tapped threaded inserts along the edge of the Core Unit accommodate those screws and ensure that the two assembly pieces are positioned parallel to each other and can hold a 7.9" wide filter between them. The combined holder bracket and front filter ring can then be attached to a Sigma 14mm f/1.8 DG HSM Art lens by tightening the Core Unit's locking mechanism.





After being fitted onto a Sigma 14mm f/1.8 DG HSM Art lens, the bearing design of this WonderPana FreeArc XL Core Unit allows a WonderPana 8.0" Holder Bracket to be rotated 360°. This permits the use of graduated neutral density and other filters that are enhanced by varied positioning.





A FotodioX WonderPana 8.0" Holder Bracket provides two pairs of filter slots, a configuration that accommodates two compatible rectangular filters. For each rectangular filter that is placed within one of the holder bracket's slots, its position is secured by integrated guides within each slot. These guides apply pressure along both sides of a filter that is sufficient to hold it in place, but permits movement of that filter. This can complement the use of graduated filters whose effect can be adjusted to better suit changing lighting conditions or creative demands by sliding them up or down within a filter slot.





This FotodioX WonderPana FreeArc XL Core Unit includes front filter threads, which allow a FotodioX 186mm round filter to be used along with a WonderPana 8.0" Holder Bracket. If a 186mm round filter is used on the attached WonderPana FreeArc XL Core Unit, the rectangular filter slot closest to the rear of the holder bracket becomes unavailable.





The FotodioX 186mm Center-Pinch Snap-On Lens Cap for Select WonderPana Systems and Filters is a 186mm front lens cap with a squeeze, spring, and snap-on mechanism. It is easy to install as well as remove and can attach to a WonderPana FreeArc XL filter holder system in order to protect the front element of a lens that any one of those systems is mounted on. Additionally, with the exception of the FotodioX Ultra Slim filters, this lens cap can be used to protect a FotodioX 186mm filter that is mounted on a FotodioX WonderPana FreeArc XL filter holder system.





Lens caps protect your lens or filter from scratches, fingerprints, and the elements when the lens or filter is not in use.The FotodioX 186mm Slim Circular Polarizer Filter is compatible with FotodioX WonderPana FreeArc XL holder systems. It helps to reduce reflections as well as glare by filtering out light that has become polarized due to reflection from a non-metallic surface. The light from the sun naturally becomes partially polarized due to reflecting off electrons in air molecules, causing the light to scatter into what appears as haze. A polarizing filter arranges, and filters, this directionally polarized light perpendicularly to the reflected light, allowing for the absorption of much of this light. This results in a noticeable reduction of glare and reflections from non-metallic surfaces and an increase in the saturation of skies and foliage.





A circular polarizer only differs from a linear polarizer in that it contains a quarter wave plane in addition to the linear polarizing filter. The addition of this quarter wave plane is to circularly polarize the linearly polarized light for the use of auto focus and exposure functions. Due to how the light is broken down and filtered with a linear polarizer, auto focus and exposure accuracy become skewed during use. When the light becomes circularly polarized, it permits the use of these functions.





The FotodioX 186mm Slim Circular Polarizer Filter is constructed from optical glass for clarity as well as color fidelity and features lightweight, slim, aluminum-alloy filter rings. A rear filter ring connects to a compatible filter holder while the front filter ring allows the filter glass to be easily rotated. This provides the ability to achieve the desired degree of polarization.





A separately-available FotodioX 186mm Center-Pinch Snap-On Lens Cap can be used to protect the front of a FotodioX 186mm Slim Circular Polarizer Filter that is placed in front of a lens.The 186mm Center-Pinch Snap-On Lens Cap for Select WonderPana Systems and Filters from FotodioX is a 186mm front lens cap with a squeeze, spring, and snap-on mechanism. It is easy to install as well as remove, and can attach to a WonderPana FreeArc XL filter holder system in order to protect the front element of a lens that any one of those systems are mounted on. Additionally, this lens cap can be used to protect a non-ultra slim FotodioX WonderPana 186mm filter mounted on a FotodioX WonderPana FreeArc XL filter holder system, with no other filter placed in front of it.





Lens caps protect your lens or filter from scratches, fingerprints, and the elements when the lens or filter is not in use. It's always good to have a spare in your camera bag.