Recently Metabones announced something that got a lot of attention. It got a lot of attention for good reason, because it seemed to be too good to be true. The "Speed Booster" adpater by Metabones made some big claims. Claims such as being able to make your lenses faster, wider and shaper... yes even sharper. At first there was a lot of skeptism. A lot of people saying "What's the catch?" As more and more test started coming to light there seemed to be less of a catch. The Speed Booster is now looking like it is something that any shooter who wants to expand their F-stop or Focal Length range on their lens kit should have.
So what exactly is the "Speed Booster"?
The Speed Booster is an adapter that allows you to take your standard Full Frame lenses and attach them to smaller APS-C and Micro Four Third mirror-less sensor cameras. However there is a lot more to this than just being an adaptor. This adapter will do a couple of big things for your lenses. The first is that it will reduce your image magnification allowing you to get a 1.09x on any focal length. Almost a full frame field of view on a APS-C sensor. For example a 50mm would now become a 35mm and a 35mm now a 24mm. So on smaller sensor cameras such as the GH2 sensor with a 2x multiplication and the BMCC with a 2.4x multiplication this adaptor will be extremely useful. Also for anyone who wants to increase their focal length of all their lenses this is a must have. So that prime 50mm Canon lens you have currently just also became a 35mm. You can start to see why people are so excited about this adapter. But wait... there's more...
The other big claim is that it will also increases low light performance by about almost a full stop. turning for example an F2.8 into a F2.0. This is great for cameras who's low light sensitivity is minimal or for a slower lens you want to use in lower light. Suddenly shooting with that F2.8 just got a little better when encountering those shots where you wish you could squeeze out a little more light. No more sacrificing image quality by increase ISO or Gain. No more changing shutter speeds and sacrificing motion characteristics to grab a little bit more light out of your lenses. This adapter will help expand your low light capability and future proof some of your lenses for what camera's come out down the road. Also suddenly not having a APS-C or full frame camera doesn't seem like such a big deal.
Now on to the sharpness claim. There is good and bad with this. There can be increase softening in the corners of some lenses with the Speed Booster which is to be expected because we can't have it all. However overall sharpness remains well maintained. The pros far out weight cons when it comes to increased low-light performance and greater field of view on your lenses.
Currently the Speed Booster is available for Canon EF lens to Sony E mount. However Metabone s as confirmed that there will be a MFT mount version coming in March. This should excite many BMCC users and GH2/GH3/AF100 users as well. That large crop factor on the Blackmagic Cinema Camera is something that will benefit more than anything else from the the Speed Booster from Metabones.
Here is a video from Andrew Reid showing just what this adapter can do.
Metabones Speed Booster - FS100 vs 5D Mark III from Andrew Reid on Vimeo.
This link below will help to explain in more detail how the Speed Booster works: