It’s back! We’re seeing the return of our semi-neglected Cinevate series this week in the 5th installment of Ask Cinevate. Part of the blame lies on the fact that we were on the road a few times these past weeks attending trade shows. Out of that comes a great topic and a reoccurring question we get from DSLR video newcomers – Why would I need a mattebox?
It all boils down to control – control over your image by manipulating the light coming into the lens. Now, we’re certainly not the first to write on the subject but what we’ve collected here is a sample platter of video and stills to show images with and without control methods the Mattebox provides. Naturally, we’re using our Titan Swing Away Mattebox and our DSLR Core Package in the video. And, free hugs to anyone who catches our attempt to reference (parody?) a recent car film… So without further ado;
I didn’t talk specifically to the filters, so to clarify, we used the following in the video; Tiffen Ultra Linear 4×4 Polarizer, Tiffen Clear/ND.6 Soft Edge 4×4 Gradient, and Tiffen ND.9 Neutral Density 4×4. So to recap, here’s a breakdown of the methods used to control and/or manipulate light (thus controlling your image.)
Flags – Flags will allow you to block direct light sources that may cause undesired effects. Of course, a lens flare can be a desired effect but we’re talking about having complete control over you image, so in cases when this is unwanted flags allow you to correct as such.
Neutral Density or ND Filters – These guys are used to cut down on light coming into the lens. They don’t otherwise change the look of the image. They commonly come in 3,6, and 9 and block 1, 2, and 3 stops of light respectively, so you’d use these filters if you wanted to shoot at a lower f-stop and have shallower depth of field.
CORRECTION* – At 1:41 in the video I put in an ND 9 and said it gives more depth of field, when I actually meant ‘shallower depth of field’
Gradient Filters – Gradients come in the Hard edge and Soft edge variety. Basically half of the filter is of neutral density (in the common 3,6,9 values) while the rest of the filter is just clear glass. In most cases you’d see these used on exterior shots on bright sunny days when your sky would be blown out. The gradient blocks light only from the sky, bringing it into a range that you can exposure properly for while still properly exposing your subject(s) on the ground (in your mids and shadows). In my samples we didn’t have bright sun but you can see how it brings out detail in my clouds while leaving the city exposure unchanged.
Polarizer – This filter is a common favourite among exterior shooters. Without getting too technical, a polarizer allows some waves of light through the filter while blocking waves of other polarizations. Because you can rotate your polarizer you control which polarized waves of light you’re letting through the lens. You’ll see these filters used to cut down on glare (or glares as I refer to them for some reason…lol) and reflections.
So there you have it. Hopefully if you came into this pondering the titular topic you have left with a better understanding of how or why you would use a mattebox. Did you learn anything, or think it was too straightforward? – Let us know! Or, if you have a question you’d like to see answered send us an email at firstname.lastname@example.org or via twitter @cinevateinc or comment below.