Matte Boxes and Grad ND filters -- Please Help

[shortnstout]

Hi,
I'm very into using grad nd filters but I use a lee holder system- getting tired of it and have been looking into a matte box. I think the Oconnor Obox is most interesting to me. I currently use a 4x5.6 grad nd filter that is vertical (so the fade goes along the 4" side) and this allows me to move the filter up and down to match the horizon, which seems essential to me.

But when I look at glass filters for cinema they seem to all be horizontal in orientation to fit the wide aspect ratio of the matte box. I know matte boxes like the Obox accept both 4x4 and 4x5.6" filters, but I'm wondering if there is a way to adjust the grad to fit my horizon. The reason they have the vertical ones is to allow extra up/down adjustment. Is there a way to put my vertical filter in the matte box?
thanks!

 

[David W. Jones]

They make both horizontal and vertical grads. Also many matte boxes have rotating filter stages so you can turn them how ever you like.

 

[shortnstout]

Thanks David! Yes, I own a vertical grad, I'm wondering if I am able to slide it up and down inside the matte box to adjust for the horizon--- and specifically interested if the obox handles this. thanks!