Sigma 8-16mm and filters

Didn't know this existed.

http://fotodioxpro.com/index.php/wonderpana-145-system-holder-only-for-the-sigma-8-16mm-aps-c-lens.html

"WonderPana 145 Filter System
The WonderPana System is a groundbreaking Lens Hood Filter System available for many Super Wide Angle (SWA) & Ultra Wide Angle (UWA) Lenses on the market today. The WonderPana System allows the use of round UV, Circular Polarizer and ND filters on SWA and UWA lenses. Round filter designs prevent the typical glare and unwanted reflection issues inherent in other designs. The Metal Hood and dedicated snap-on lens cap of the WonderPana System provides excellent protection for your valuable lens investment(s). The WonderPana is ideal for Panorama, Nature, Architectural, Fashion and Event photographers and is an invaluable asset for Analog and Digital Filmmakers alike.

The WonderPana 145 System is designed from the ground up to accommodate round UV, Circular Polarizer and ND filters on SWA and UWA lenses. The WonderPana 145 System works with all Fotodiox Pro 145mm round filters, including: Multi-Coated UV filters, Circular Polarizers and Neutral Density 4, 8, 16 and 32 filters. The WonderPana145 can be upgraded to the WonderPana 66 System which will allow for the use of the industry standard 6x6” square from Schneider, LEE, and Cokin as well as the Fotodiox Pro 6x8" rectangular filters."

Same, but for the Tokina 10-17mm which I assume will work for the DA 10-17mm as well.

http://fotodioxpro.com/index.php/wonderpana-145-system-holder-only-for-the-tokina-10-17mm-aps-c-lens.html

Thank you
Russell