If you're film making with one of the Blackmagic Pocket Cinema Cameras, you might find some extra cinema tools and accessories, helpful. Here are some of the most popular ones and how you can put them to great use.
Add a Follow Focus for Precision
What is Follow Focus and How Does it Work?
A follow focus is a filmmaking mechanism to help you focus more accurately and quickly.
A gear ring is attached to your lens, basically a strip of plastic or rubber that fits snugly and has ridges or teeth. Gears are then attached to this ring, on an arm or rod, and lead to a wheel or knob that, when adjusted, turns the teeth, and so, the focus ring on the lens. There’s also version where instead of having the follow focus mounted directly on the camera you have a remote-activated mechanism.
That’s essentially a follow focus at the most basic, but designs do vary widely. Some include a white disc, which can be very useful for reasons I’ll mention in a moment.
Why Use a Follow Focus?
Auto-focus frequently isn’t up to par and will focus on the wrong thing, or ‘hunt’ for focus. Many filmmakers primarily manually focus and, depending on the lens, that can be very awkward and fiddly.
Lenses with wide apertures are great, but they tend to be physically smaller, making them hard to use accurately. When working at very wide apertures sharp focus can be hard to achieve manually, and very unforgiving if you’re even slightly off. Particularly in modern, cheaper, plastic lenses, the focusing rings are pretty terrible. Say you’re filming an actor, and they move even a little, it would be really hard to smoothly keep track of them because you’d need the smallest movement of the focus ring to correctly adjust for it. Because of the little notches or teeth, you can get much more precise, smaller movements using a follow focus without inching forwards and backwards.
Racking focus is a popular cinematic technique to do things like create tension, or to ‘reveal’ something, and it's best done with focus gear! If you’re intending to rack focus, you’ll be focusing on one object/subject and then immediately focusing on another.
Here’s a great, simple example: Focus Rack on Designer Working on a Digital Tablet Known As Digitiser from Envato Elements creator DC_Studio.
A useful way to effectively rack focus is to work it out beforehand and mark it onto the follow focus. Many come with a white disc, which is something you can write on and wipe off easily, like a dry erase board. The idea would be to note which notch is your first focus, and which is your second, so you can smoothly move to that notch and be confident that your focus will be accurate and sharp.
How to Choose a Follow Focus
A follow focus varies wildly in price depending on what you want, from around £60 to hundreds of pounds. If it’s something you’ll make frequent use of, it’s best to purchase something of good build quality, as many of the very cheap ones can have too much play in the mechanism.
If you’re using a physically small lens, and particularly if you’ve adapted photography lenses for filming, they might be so small that you’ll have a hard time fitting a follow focus to them, so that’s something to be aware of, though of course adapters exist to give the lens a larger diameter.
Hoods and Matte Boxes
A lens hood is a little shade that you put on the front of your lens to help prevent glare or flare from a light source. They can also stop the lens from collecting raindrops so easily/quickly in a light rain, and they have the added benefit of protecting your lens from bumps and scratches.
A matte box mounts to the front of the lens and serves the same purpose as a lens hood, but with more flexibility. It has four individual ‘flaps’ (French flags, or barn doors as they’re also known) that you can move independently in order to block light from one particular direction. Some matte boxes have the added function of being able to hold filters.
How to Choose: Lens Hood or Matte Box
Lens hoods generally come in two shapes: cylindrical, or petal; both do the same thing. Quite often, lenses come with them, but if yours didn’t or you need another one, you’ll need to make sure it’s the right thread size to fit on the desired lens.
With a matte box, you have more flexibility. They generally come with different attachments so you can use them across different lenses. And, if for whatever reason you have a lens that the matte box attachment doesn’t fit, you have an option to clamp it to rods/bars and then cover any slight gap with a fabric lens donut.
Choosing a matte box with the option of adding filters is another thing that can make life easier. If you have a lens plus hood, it can be fiddly to get a filter on without taking the lens hood off, then putting it back on afterwards, and that’s even if you can use both at once. With a matte box, you can use the same filters across all your lenses that fit the matte box, and you don’t have to take off the box to put on or take off a filter.
Filters are an essential tool for filming, and they come in a dizzying variety.
What Are Filters & What Do They Do?
Filters are bits of glass that we use to cover a lens, and fulfill a variety of functions. Here three of the most popular filter types and what they do
- UV – these stop UV light and were really more appropriate when shooting with film, but some photographers and filmmakers still swear by keeping one on the lens for protection though there’s not a lot of evidence to say this really works and putting another layer in front of your lens can only degrade the quality.
- ND – Neutral Density (and graduated neutral density) filters bring down your overall exposure, either entirely or in the case of graduated ones, over a part of the image, like a bright sky. They come in various ‘stops’ but beware colour casts caused by cheaply made ones.
- Polariser – cut glare and reflections caused by sunlight and are a little like ND filters but without the dramatic darkening effect.
How to Choose Filters
Attach Directly to Lens: Circular Filters
The previous section leads on nicely to filters. As mentioned, if you’re using screw-on filters you’ll need to make sure that either they, or an accompanying extension ring are the right thread size for your lens. You’ll find the thread size on the back of your lens cap.
Use Filter Sets With a Holder: Square Filters
You can also buy filter sets that come with their own adapter rings and work in the same way as above, you screw the appropriate adapter ring to your lens and then you slot in the filter.
Matte Box: Square Filters
As mentioned above, some matte boxes have spaces for filters. These work the same way as a filter holder, but with the added benefit of having the flags to block out light.
Base your filter choice on quality and functionality. It's no good having a great lens and then putting a cheap glass filter in front of it, so invest wisely in your filters and you'll be using them for years to come.
There are lots of useful cinema tools and it's good to have one or more of these in your filmmaking toolkit. Here's a quick reminder of some of the things to keep in mind when looking at cinema tools:
- A follow focus is useful but not necessarily essential, it depends on your type of filming. If you do need one, invest in a good quality mid- to top-range one.
- Every filmmaker should have hoods or a matte box to help deal with unwanted light glare or flare. Adding a matte box with space for filters can give you extra functionality and flexibility.
- Filters are handy but it's better to have a few really good ones than a bunch of cheap ones. Try adding a polariser and some neutral density filters to your kit first, these tend to be the most useful. You can add them to a specific lens if required, but again you'll get more flexibility out of a set if you can use it easily across lenses, which will come by using either a square filter holder or a matte box.