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Metabones Speed Booster Review

David Thorpe reviews the Metabones Speed Booster with Micro Four Thirds, designed to give brighter, sharper images.

| Metabones Speed Booster in Convertors and Other Adaptors

Handling and Features

Metabones Speed Booster Review: Speed Booster

The Metabones Speed Booster looks like a tele-converter but that is exactly what it is not. The familiar tele-converter increases focal length and decreases light intensity at the sensor. The Metabones decreases the focal length and increases light intensity at the sensor. 

The conversion factor is 0.71 times. Doing the maths, a 50mm f/1.4 lens becomes - rounded slightly - a 35mm f/1 lens. There’s a catch, though, because the Metabones works by mounting a lens designed for a 36x24mm full frame sensor and converting it to a smaller format.

In the case of Micro Four Thirds cameras with a 2x crop factor, that 35mm f/1 has the angle of view of a 70mm lens on full frame. Even so, an f/1 lens is pretty spectacular. 

But there’s more. The 50mm lens’s resolution is normally spread over a bigger sensor. Focus it on a smaller area and it should be sharper. That’s the theory.

Metabones Speed Booster is available from Metabones, and is able to convert many of the major lens makers’ full frame SLR optics to mirrorless cameras, Micro Four Thirds, Sony, and Fujifilm cameras among others. This review is on Metabones’ Nikon to Micro Four Thirds Converter.

Metabones Speed Booster Handling and Features

Metabones Speed Booster Review: Metabones On 200mm
Metabones with 200mm Nikkor

The Metabones is solidly made in brass and chrome and matches the quality and feel of all metal legacy lenses perfectly. When fitted you would not know it is there as there is no play between the Metabones and lens or body mounts. It adds about 2cm to the lens length, rather less than a standard non focal length changing MFT/ Nikon adaptor.

Metabones Speed Booster Review: Metabones On 200mm
Metabones with 200mm Nikkor

There is a ring numbered 1-7 at the rear which is for altering aperture with lenses that do not have their own aperture ring. This is set to position 7 for lenses which do have their own ring. I would have liked a lock on this position. 

Metabones Speed Booster Review: Metabones On 300mm
Metabones On 300mm Nikkor

A thoughtful touch is the tripod mount. Given how heavy full frame lenses can be and how small and light Compact System Camera bodies are, the Metabones with its substantial construction is better placed to take the strain than a camera body screw with all the unbalanced weight pitched forward.

Metabones Speed Booster Performance

The Metabones promises a faster and sharper version of the lens to which it is attached. Can it deliver?

The short answer is yes. I use only Micro Four Thirds equipment, a system which has available a wide and ever expanding range of lenses. The one area in which it is lacking is fast telephotos, the equivalent of the 300mm f/2.8 or 400mm f/4 for full frame. The only contender is Olympus’s 40-150mm f/2.8 zoom lens, a fine lens but like its FF equivalents, expensive. 

I bought a couple of old 80’s Nikkor lenses, a 200mm f/4 and 300mm f/4.5, compact for their era and with excellent optical performance. Both are all metal construction and have the quality feel that only all metal construction can deliver. I paid just over £200 for the pair of them.

With a standard adaptor these have the full frame equivalent angle of view of 600mm and 400mm respectively on Micro Four Thirds. 

With the Metabones, they become equivalent to full frame lenses of roughly 400mm f/3.2 and 300mm f/2.8, actual focal lengths 210mm and 140mm. The Metabones certainly supplies the focal length shortening and the 1 stop aperture increase. 

Metabones Speed Booster Sample Photos

What about the sharpness? Here are some examples. You can see that not only is sharpness increased but so is contrast. In the case of the 200mm f/4, without the Metabones I would generally stop it down to f/5.6 for best performance where sharpness and contrast is an order of magnitude better than f/4. 

With the Metabones, making it a 140mm f/2.8, sharpness is such that I would generally use it at that aperture to obtain the highest possible shutter speed and least possible depth of field.

The 300mm Nikkor is already crisp and contrasty at f/4.5 and with the Metabones, making it a 210mm f/3.2, sharpness and contrast are further improved.

On these long lenses edge to edge sharpness is excellent but you’d probably want to stop down a couple of stops with wide angle primes or zooms. Good as it is, the Metabones is still an adaptor!

This Metabones has no electronic contacts so focusing must be manual and auto-exposure is limited to aperture priority. With the long lenses I have used here manual focusing is easy, especially given the extra brightness and diminished depth of field the Metabones yields. In fact focus just snaps in and out, especially with peaking or focus magnification enabled on the camera. 

Metabones Speed Booster Verdict

This is a quality made adapter that - to my surprise - does everything the makers claim for it. I like the element of lateral thinking it represents, taking the familiar lens converter concept and turning it on its head. 

There are a multitude of manual lenses from film days available on eBay and dealers like Mr Cad. Many, from makers like Nikon, Canon, and Leica were very expensive and optically highly sophisticated. The idea of being able to convert these into high speed optics for APS-C, MFT and other smaller sensor cameras is an exciting one.

I paid £320 for the Metabones Speed Booster, plus £140 for the Nikkor 300mm f/4 and £80 for the Nikkor 200mm f/4. For a pair of fast long telephoto lenses this is a bargain and makes the Metabones Speed Booster excellent value for money. The more lenses you use it with the more of a bargain it becomes.

Metabones Speed Booster Review:  
The Metabones Speed Booster enhances image sharpness and contrast giving a brighter image from older lenses.  

Metabones Speed Booster Pros

Robust metal construction
Doubles lens speed
Enhances lens sharpness
Enhances lens contrast
Solid removable tripod mount
Adds choice of hundreds of new lenses for CSC users 

Metabones Speed Booster Cons

No lock on aperture ring
Doesn’t work with FF cameras



Review by David Thorpe (Lemmy).

You can watch David Thorpe's video review of the Metabones Speed Booster here.

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dannyr 13 46 United Kingdom
26 Feb 2015 12:27PM
What a wonderful invention!

It's makes you wonder why nobody thought of it before.

Well done Metabones.
ChrisV 16 2.3k 26 United Kingdom
26 Feb 2015 2:08PM
I'd strongly consider this, but I have one of the original Olympus 4/3 50-200 2.8-3.5, which means I've effectively got a 400mm equiv f3.5 [and it goes out to that quite slowly], so it would be f limited use - especially since it does autofocus reasonably well on the EM1.

Whilst the idea of a cheap 50mm f1.8 becoming something like a 70mm f1.2 definitely has appeal, it would have relatively little application. Where I do feel a gap is a fast/wide lens and it looks like using the metabones to achieve that would be both very expensive and very bulky.

I suppose buying the metabones and a Nikon 35/1.8 would get you somewhere near the Nokton 25/0.95 for a good bit less money. That's worth a ponder...
20 Jul 2015 11:10PM
I wonder if it would be possible to use a Sigma 8-16mm f/4.5-5.6 UWA lens on the Metabones Speedbooster XL 0.64x to convert it to an equivalent 10.24mm super-duper UWA on a MFT body (only certain bodies will work with this adapter) -- that would be even wider than the new Canon 11-24mm designed for FF cameras. I'm guessing this would require cutting off the lenshood petals, something to consider along with available image circle when adapting any UWA lens in this way.

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