What is one of my most satisfied gears I purchased for these years? It is this one: Metabones Speed Booster Nikon to Micro Four Thirds. It raises the quality of my current camera equipment to a new level. It is kind like a magic. If you using m4/3 system, this is a must have gear in my opinion.
There are many reviews on youtube tell you how this thing works. Basically it is a 0.7x wide angle adapter. But instead put it in front of lens it put between sensor and lens mount like how you would use the teleconverter. However that not enough. The best part is that it also boost the lens’s light gathering ability by 1 stop. So for example your f2.8 lens become f2.0. My particular model is to adapter Nikon lens to m4/3 camera. You can read information at b&h.
The lens I am using for this test is the Nikon mount Tokina 11-16mm f2.8 lens. It is a lens design for APS-C sensor. Camera used is Panasonic GH3.
It can adjust the aperture even your Nikon lens does not have the aperture ring. But you have to guess what f stop you are at. Normally each number is about one stop difference, but still depend on your lens.
Below is a normal cheap Nikon to m4/3 adapter. So no extra light and no filed of view change.
In my opinion even if you only bought the speedbooster for this lens, it is still worth it. This combo cost about $900. The native Panasonic 7-14 f4 cost $960. I can not use that lens for video because f4 is not going to cut it in low light situation.
Ok let’s start some test. First let’s compare the field of view of tokina 11-16mm with speedbooster and without.
Let’s also compare it to native Panasonic 12-35 f2.8 lens set at 12mm. Tokina 11-16 with speedbooster set at 16mm.
As you can see 16mm with speedbooster is still wider than native 12mm. 12mm on m4/3 is 24mm full frame equivalent. so 16mm with speedbooster is something like 22mm full frame.
When set at 11mm, it is really wide. It is like 15-16mm full frame equivalent. You will notice some black edge. It can not completely cover the sensor now. Remember this lens is designed for APS-C sensor which is 3:2 aspect ratio. m4/3 is 4:3 ratio. If we cut off a bit of top and bottom image to make it a 3:2 aspect ratio then the black edge will be gone. And it is totally fine when shooting 16:9 video. So now I have a 15/16-22mm full frame equivalent lens. And with aperture f2.0!!!!! Remmeber it gains 1 stop light gathering ability. Ok now let’s do some test about the aperture effect.
As you can see, I reduce the shutter speed by 1 stop with speedbooster and still got same exposure as the the image at left. So it does indeed gain one stop light. It is like I am having a f2.0 lens now. Amazing. It is so useful when shooting video indoor.
last let’s exam the sharpness. If it is very soft to a degree that is not usable when at f2.0, then we would not want to buy it.
click image to see 100% crop
Very good result. Center sharpness always stay very high. I see no issue use f2.0. and corner become very sharp at f5.6. should be even better at f8. This is a very extreme corner test. Anyway all ultra wide angle lens has soft corner when set at wide open.
For video, it will look very good. Should be very hard to notice this degree of softness on 1080p resolution.
Here you have it. An amazing product for the price.