Canon Lenses On The Panasonic GH4, Using The Metabones Speedbooster Adapter

Canon Lenses On The Panasonic GH4, Using The Metabones Speedbooster Adapter

In a recent article by Jaron Schneider about the Metabones Speedbooster on a Black Magic Pocket Cinema Camera, several readers had questions about the model designed for the GH4, whether this one would work with it or not, and other comments. I bought one of these a week ago and wrote this article to tell you what works, and what doesn’t.

There are several different lens adapters that Metabones makes. Some not only adapt to fit lenses but alter the recorded image by increasing exposure and the field of view. For the sake of explanation here are the three particular models that have been discussed recently in Jaron’s aforementioned article comments, and will be noted further below.

  1. Canon EF Lens to BMPCC (Black Magic Pocket Camera) Speed Booster BH | Metabones
  2. Canon EF Lens to MFT (Micro Four Thirds) Smart Adapter BH | Metabones
  3. Canon EF Lens to MFT (Micro Four Thirds) Speedbooster BH | Metabones


Around the web, people seem to be using the MFT models primarily for the Panasonic GH4 and GH3, but unless otherwise noted by Metabones, they can work on other MFT mount cameras.

What makes this a little confusing is that the BMPCC is an MFT camera. The difference is that with the BMPCC version, the adapter has been configured to work with BMPCC specifically. If you attempt to use that adapter on the GH4 for example, you will get an error (according to this Phillip Bloom article) and some report that if you screw your glass forward to fit it, you will break the focus (comments section of this video.) The short story is this: It's not recommended and likely won't work. The great thing is that now you don't have to even try since there is an adapter specificially for the GH4.

To add some more confusion into the mix, there were reports on EOSHD of the BMCC model of adapter (WHICH IS NOT THE POCKET CAMERA ADAPTER) being used on a GH4 with a Nikon lens. My guess is that some readers mistook BMCC for BMPCC when reading, or assumed that if an adapter worked for one, it would work for the other?

In any case, Metabones has available an "MFT" adapter, which is absolutely meant for the GH4.

There are two versions, a smart adapter and a speed booster. They are mostly the same except the speed booster will increase the sensitivity of your lens by 1 stop, and make the effective focal length about .71x wider. There are a lot of other details that you can read about right here on the Metabones web pages for either the Smart Adapter or the Speed Booster.

I got myself the Canon MFT Speedbooster to use on my GH4, and below I'll note some of the lenses I've used it with. I'll also include the approximate calculations for what a lens range becomes on the GH4 with the Speedbooster, as well as their approximate full frame equivalent focal lengths. If you'd like to do the math yourself on a lens you own, multiply the adapter FOV reduction (.71) by the focal length of your lens. This gives you the focal range of the lens on the GH4. If you want to know the approximate full frame equivalent, just double that number.

Canon 24-70L f2.8 II becomes a 17-50mm f2.0 on the GH4, or 34-100mm f2.0 FFE

Canon 70-200L f2.8 IS becomes a 50-142mm f2.0 on the GH4, or 100-284mm f2.0 FFE. The IS was functional.

Canon 16-35L F2.8 II becomes a 11-25mm f2.0 on the GH4, or 22-50mm f2.0 FFE

(no image, but tested and it works)

Sigma 15mm f2.8 becomes a 11mm f2.0 on the GH4, or 22mm f2.0 FFE

Sigma 17-50mm IS f2.8 becomes a 12-35.5mm f2.0 on the GH4, or 24-71mm f2.0 FFE. The IS was functional.

Sigma 10-20mm f4-5.6 becomes a 7-14mm f2.8-4 on the GH4, or 14-28mm f2.8-4 FFE

Rokinon 16mm T2.2 becomes a 11mm T1.6 on the GH4, or 22mm T1.6 FFE

Rokinon 35mm T1.5 becomes a 25mm T1.1 on the GH4, or 50mm T1.1 FFE

All lenses I tested worked, but the Rokinon lenses were not recognized by the camera. This was easily bypassed with a simple menu command, then they worked. There was no communication between the lens and the camera, and lens EXIF data was not recorded either.

The aperture displayed f0.0, which is what happens when these Rokinon Cine Lenses are used on Canon bodies since they are manual aperture lenses. Additionally, as far as I could tell, these lenses did NOT damage the adapter, but Metabones warms that some MF lenses can harm it. Try third party manual focus lenses at your own risk, and do your research online before doing something that might damage your kit. Metabones does have tech support, so you can reach out to them if you have specific questions about a particular lens, or what to look for in a lens that might damage the adapter.

Some thoughts about the lens/adapter combinations

It's very interesting to look at the stats from lenses with the adapter, and compare them to the standard lenses you might normally use with the GH4.

For example, the Sigma 10-20mm was very wide at 10mm, and right now the widest lens available for the GH4 (that I could find) is a Panasonic Lumix 7-14 f4, and it cost me almost twice what I paid for that Sigma lens, many years ago. It makes me want to do some lens tests to see if the quality of the Sigma holds up, because if it does, it is a stop faster than the Lumix lens and would make it my go-to wide angle when weight isn't a concern.

Now look at the Sigma 17-50 f2.8 IS. My go-to lens for the GH4 is the 12-35mm f2.8 IS, which is a solid little lens. But with the Sigma and speedbooster combo, I get effectively the same FFE focal range (24-70ish) but I get another stop of light to work with.

Of course the catch is that you lose AF ability by using the adapter. Honestly I don't miss it, I'm very used to using manual focus (for video) so much that it is not an issue for me, so remember that before you take the plunge on the adapter yourself. I hope these finding were helpful to you. I can't test it with lenses I don't have, but I'm happy to answer any other burning questions your may think of. Leave a comment below!


Mike Wilkinson's picture

Mike Wilkinson is an award-winning video director with his company Wilkinson Visual, currently based out of Lexington, Kentucky. Mike has been working in production for over 10 years as a shooter, editor, and producer. His passion lies in outdoor adventures, documentary filmmaking, photography, and locally-sourced food and beer.

Log in or register to post comments

Great post Mike, thanks for doing these tests. Did you notice any flex in the GH4 body when using the 70-200 or 24-70? I’m curious how the body holds up to heavier lenses that the camera may not be designed for. Thanks!

Definitely a little bit of flex. Wouldn't recommend leaving a long/heavy lens attached without screwing in the lens itself to the tripod mount. I did in the image above, but wouldn't do it again for anything more than a quick use.

Thanks Mike, I usually have to do that with my T4i too, and that camera is cheap plastic. I think the GH4 is a little sturdier.

Mike - Can you post some comparison photos of the Rokinon 35 wide open on the speedbooster? I've used that setup on a GH4 with Nikon speedbooster, but I find the image is really not that great until stopped down at least 2 stops. Curious to see what results you get.

i'm on the road for a while without that lens, so I can't test that anytime soon for you. I do recall that using digital zoom on the LCD image revealed wide open, it was not very sharp, but then again, I didn't expect it to be as such a wide aperture. I will likely conduct some tests on my own time... when I have the time :-)

The Sigma 17-50mm is an APS-C lens? Since the SpeedBooster is originally made for FF lenses, this lens does not vignette in the GH4?

This confused me at first as well. The GH4+speedbooster combination effectively turns the camera into a roughly APS-C sized image circle. The key is that this works with "EF" lenses. I had been equating EF with full frame and EF-s with APS-C . But 3rd party APS-C lenses also use the EF mount (not EF-s), even though they are designed for the smaller sensor. EF-s is a mount that is designed exclusively for the smaller sensors and Canon have not opened to 3rd parties.

The speedbooster works with EF lenses, so that Tamron/Sigma 17-50 or 18-35 or Tokina 11-16 all work. I have this combo myself and use both the 18-35 and the 11-16 all the time.

Fahnon in your experience with the Tokina 11-16 and Speedbooster, does it vignette below 15mm? I've used that on full frame cameras and found it could be used at 15-16, so I assume that's where the extent of the coverage was.

It works from 11-16. The GH4+SB in 4k (UHD) uses the same image circle as a crop body, so it's the same as you would get on a 7d.

What Fahnon said ^

Anyone else having this problem,

Got my GH4 the other day and my metabones speedbooster m43 to Canon EF mount

Great to see this range of lenses used on the speedbooster. It'll certainly help me deciding what focal lengths to add to my kit. I have GH4 with the Nikon-MFT speedbooster and the Sigma 18-35 f/1.8, can't speak highly enough of it. I have a very simple test clip here

Anyone had any luck using the standard m43 speed booster on the pocket camera? Still struggling to understand why the one dedicated to the BMPCC is 60 dollars extra than the regular m43 mount.

It is very simple why, because the one that is designed for 4/3" sensors works on all m4/3 cameras. Yet the BMPCC version is designed for roughly 1" sized sensors (giving the benefit of an even wider FoV and an extra boost to the f-stop), thus won't work right if used on cameras with larger sensors.

It is very simple why, because the one that is designed for 4/3" sensors works on all m4/3 cameras. Yet the BMPCC version is designed for roughly 1" sized sensors (giving the benefit of an even wider FoV and an extra boost to the f-stop), thus won't work right if used on cameras with larger sensors.

I find Metabones to be overpriced for what it is. And Canon is a poor choice of lenses to adapt to other cameras. Nikon F is far more universal, and more future proof investment than Canon lenses (well... so much as you can in this fast changing world).

Check out instead the RJ Lens Turbo:

Any help with a question? I have a 25 mm pana-leica lens. the m43 conversion factor makes it 50 mm. If I was to attach a speedbooster with say a Nikon 35 mm (which after the math, would be roughly a 50 mm as well), would I get a greater depth of field as compared to the panasonic lens, or would it be exactly the same? Would there be any differences?

That Samyang 35mm was my go to lens for pretty much every gig when using the 550 or 7D. I loved it. What lens is recommended with the speedbooster for a similar field of view as the 35mm on the Canon? Also some test footage of the 35b mm Rokinon used with the Speedbooster would be great!

Does focus peaking still work on the Rokinon line?

Hello Mike, does the aperture go all the way open and then to the set aperture when changing? How does the changing of apertures compare to changing on an actual canon? For example, when recording and you need to stop down or up, is it a subtle change or does it make the shot un-usuable. Thanks for your time to review. -Jay

Did you also have s vignetting in your footage with the sigma 17-50?