Ok, but why do you need a matte box .... if it's for looks then don't waste your money! Most, if not all lens hoods do as good a job! If, you already have expensive 4" x 4" filters that you want to use then I can see the reason to use a matte box as it has a 4 x 4 filter holder.

Hi Chris,

I'm going to mention the Cokin Modular Bellows again as a compromise. Self supporting, very light and with a built-in filter holder. No French flags, but being of bellows construction can be angled somewhat to emulate them. I have found it very useful to help combat flare when using single coated or uncoated vintage lenses.

Cool? Depends on whether you like a red hood or not! Definitely useful.

Dave

i take today the fotga 3000 looking for rod system

FOTGA DP3000 15mm Rail Rod Baseplate Mount Support For HDV DSLR Follow Focus Rig | eBay (http://www.ebay.co.uk/itm/FOTGA-DP3000-15mm-Rail-Rod-Baseplate-Mount-Support-For-HDV-DSLR-Follow-Focus-Rig-/191193752641?pt=UK_Photography_Movie_Camera_Accessories&hash=item2c84092441)

Fotga DP3000 M4 15mm Rail Rod Quick Release Baseplate for DSLR Follow Focus Rig | eBay (http://www.ebay.com/itm/FOTGA-DP3000-M4-15mm-Rail-Rod-Quick-Release-Baseplate-For-DSLR-Follow-Focus-Rig/171179333587?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D27538%26meid%3D980e6ecfa6a6431ab23c2db28afe b4c5%26pid%3D100005%26prg%3D11353%26rk%3D3%26rkt%3D6%26sd%3D231243590982&rt=nc)

or this http://www.ebay.com/itm/Camera-Mount-Adapter-Plate-Clamp-fr-15mm-Rod-Support-DSLR-Rig-Follow-Focus/231243590982?_trksid=p2054897.c100204.m3164&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D20140407115239%26meid%3Ddd54d409194e437d8ea 6d9571bd890f9%26pid%3D100204%26prg%3D20140407115239%26rk%3D22%26rkt%3D30%26sd%3D281439494929

in first link in the rails is greater, the second is smaller How to get to nex50?

It would surely make sense to see what size the matte box is before you buy rails and fittings that might be too high to adjust the matte box

However if you are sure that your proposed matte box will fit the rails then I cannot see why one would need 20" rails ..that's longer than the camera !! 30cm rails are normal.

I ask what was fit with fotga dp 3000 with nex50
the 20" rails is very small 40" rails need with extra plate for shoulder like this http://www.ebay.com/itm/FOTGA-DP3000-M1-Steady-Shoulder-Support-Pad-For-15mm-Rig-DSLR-Rod-Suport-System-/400594640741?pt=AU_Cameras_Photographic_Accessories&hash=item5d454d1f65