Hey i'm curious to know what this addon is on the this DVX100 camera. Is it a necessary accesory? I'm guessing its an added on lens hood with a top barn door.. curious oh who also sells this addon product.

It's a matte box, and I think its made by Century Optics. It's basically something that can hold a lot of different kinds of filters and stuff like that. However, the box alone will cost you something like 600-800 dollars, nevermind the filters.

To me, that matte box doesn't look like it has a filter holder, unless it's that round part behind the matte. But then it would use round filters, and the DVX comes with threads for filters doesn't it?

Actually i don't know if they even make threadless round filters. They might.

Anyway, matte boxes are good for keeping other light from coming into the lens when you don't have control over your environment.

Shooting outside, light is coming in from everywhere, and it could be throwing off your exposures, cause weird, unwanted flares, and messing with the colorcast of the image. The farther out you pull the mattebox, the more light it is cutting out from the sides.

The barn door is good when you have things like the sun, a streetlight, or a backlight on your actor, and you need a little shade to cut out the glare that's falling on the lens.