Get Started with Speed Boosters

Alongside our main post this week, Get Started with Filmmaking; we're going to talk about Speed Boosters as part of our Get Started series.

Hearing that an adapter can actually make your lenses wider and faster sounds a bit like science fiction, but it’s true and they are incredible.

What is a Speed Booster?

The Speed Booster is what’s called a focal reducer, basically an inverted teleconverter. Where a teleconverter increases magnification, the Speed Booster has a magnification (up to around x0.71). Because of this, more of the image and more light is able to fall onto the sensor.

For budget filmmaking the Speed Booster is an impressive piece of equipment and can make your APS-C or MFT camera capture images that bit closer to a larger format camera.

We love 'em

When we started out with digital cinema cameras; instead of the EF mount version of the Blackmagic Design Cinema Camera 2.5K, we chose the MFT mount specifically because we could fit it with a Metabones Speed Booster.

We also had the original Pocket Cinema Camera (1080p) with a Metabones Speed Booster and when we sold it; we retained the Speed Booster from that for our Micro Studio Camera 4K which now sits much more nicely alongside our URSA Mini Pro 4.6K camera.

Why would you need one?

So wider and faster wasn't enough for you?

Let's get into it a little more.

When you attach a full-frame lens to the Speed Booster, it will give your APS-C or MFT sensor nearly full-frame coverage out of that lens, while increasing the amount of light hitting the sensor by one stop. So a 50mm f/1.4 effectively becomes a 35mm f/1.0 as far as your camera sees it.

Making your smaller sensor camera more equivalent to an S35 camera makes it much easier to use for filmmaking as you don't have to perform calculations to find the equivalent of this standard and when shooting alongside larger sensor cameras you can often use the same lenses or focal lengths and therefore match your footage much more easily.

Which should you get?

There are a number of budget options appearing on the market now and offer incredible results but genuine Speed Boosters from Metabones are widely considered to be unbeatable even though they demand a much higher price.

We have used Metabones Speed Boosters for years and have been blown away with their quality, more recently we have used a Viltrox Speed Booster on our Blackmagic Design Pocket Cinema Camera 4K and whilst being really impressed with the optical quality, especially given the low price; we've really struggled with focus at infinity and have had to do some work on the adapter in order to get it to do so.

If price is a concern then certainly go for a cheaper option but make sure you check out reviews beforehand and ensure your camera focusses correctly before you begin a shoot, otherwise get the Metabones as you won't be disappointed and having something you can truly rely on is really important.

But they're just for small sensor cameras?

Well generally yes, but there have been some options created for cameras with larger sensors; Blackmagic Design URSA, URSA Mini and URSA Mini Pro cameras have seen a type of Speed Booster (known as the Magicbooster) made to fit inside the camera body, between the sensor and the lens.

We haven't explored these as we haven't felt the need but they have received good reviews and there are possibly other options available for other cameras.