Category: Review

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Explaining The Speed Booster Test pt.1

I received a few emails about the video recently published comparing a Pixco v BMCC Metabones so I wanted to explain it a little further. I chose the Sigma 18-35mm 1.8 APS-C lens because that seems to be the most widely used zoom ef lens for mft systems due to sharpness and speed (lowlight). 

So why choose a generic Pixco .71x 1 stop to compare against the BMCC Metabones .64x 1 1/3 stop? Because many forums have been debating if the old BMCC Metabones could be used on the BMPCC4k and many claim that it works perfectly fine. The Pixco was used because it is insanely low priced and I already owned it. I also already own the BMCC Metabones.

So then, why the vignetting and distortion on the BMCC Metabones? Well the lens is APS-C and the BMCC Metabones is a .64x which is designed for a smaller sensor than the one on the BMPCC4k. Therefore it vignettes and distorts. Although after corresponding with Metabones they said the BMCC Metabones .64x is the same crop as the XL but not sure “if the rear element will tip the shutter/filter” of the BMPCC4k. The XL .64x and the Ultra .71x are for full frame lenses while the Ultra .71x should be used for the APS-C. There is nothing wrong with the design and function of the BMCC Metabones it was just designed for a smaller sensor and will crop and distort with an APS-C lens on the BMPCC4k

And why is the Pixco slightly “darker” than the BMCC Metabones? It is due to the fact that the BMCC Metabones is 1 1/3 stops and the Pixco is 1 stop which causes the Metabones to allow 1/3 more stops of light in. Therefore making the image slightly lighter and more pixel/color data is obtained by the sensor. 

Choosing the right focal reducer depends on what type of glass you own. 

Keep the magic alive, 

MT
editor/founder

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BMPCC4k Speedbooster pt. 1 Generic v BMCC Metabones

Make sure to subscribe to the first tech blog dedicated to the BMPCC4k.

In this video we see if you can use your old BMCC Metabones speedbooster .64x/ 1 1/3 stop and we compare it to the generic Pixco .71x 1 stop, both are ef-mft. We paired them together with the Sigma 18-35mm 1.8. All the settings are the same (4k dci, 24 fps, raw 4:1, film, 400 iso). 

We also will be comparing the generic Pixco speedbooster with the Viltrox ef-m2 in a few weeks. So subscribe and follow us!

Thoughts: I would not use the BMCC Metabones at all due to the distortion and vignetting. Even at 24 mm the vignetting is pronounced. While the generic speedbooster is slightly warmer and has a little less light it can easily be adjusted by bumping up the iso/exposure and in post doing a little more color grading. Don’t forget the metabones has 1/3 stops more. The generic looks sharp and definitely a great tool that I am sure can be found relatively cheap. I think I paid $89 when I bought this a few years ago for my GH4. The only downside of the generic is that there is no iris control. I look forward to testing it against the Viltrox ef-m2 in a few weeks. 

The advantage of using Davinci Resolve to unlock the true pixel data cannot be understated. For years I have been using Premiere Pro but will be using Resolve 15 from now on. Did I mention that it can even play Raw files! Good luck trying to even import them into PP. Anyways, I hope this may help you out in your quest for resources. 

Keep the magic alive, 

MT
editor/founder

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