The Variable ND Filter has actually been around for sometime. I think it is based on a double polarizing effect that either darkens or lightens depending on the rotation of the filters with each other. I do know that it works well to get your lens wide open and decrease your DOF. I would also call this a kit essential. This is always in my bag and I would highly recommend having some kind of ND filtration with you at all times. A variable ND filter can also work well for front of the lens “Iris Pulls”. Light Craft Workshop sells the 77mm Fader ND MK II for $125 US on their site. The 82mm Version Retails for $192.
*To Get this 82mm LCW Fader ND MK II all you have to do is follow @LightCraftWork on twitter on post the text in quotes below. They asked me to wait for this promotion. I just couldn’t. Sometimes it’s better to ask forgiveness than permission. Winner will be announced May, 28th 2010 via Twitter.
“Follow @LightCraftWork & @goforjared to win a Light Craft Workshop 82mm Fader ND MK II Variable ND Filter. www.cinema5d.com/news”