GH4 & Metabones EF to MFT Speed Booster & A7s Together. Hands On Review

September 4, 201413 Comments

When the new EF to Micro Four Thirds Speed Booster came out I jumped on it. I’ve been waiting a long time for an electronic adapter that didn’t require a battery so I could use my Canon EF lenses. The wait is finally over.


As you can see I’m happy and so is my reporter friend who photo bombed me. ūüėÄ

I have to say I love this adapter! With the added bonus of a Speed Booster it effectively turns the GH4 into a S35 camera with full frame EF mount lenses. But does it deliver as a Speed Booster? Yes it does. In real world shooting I found no visual issues with the Speed Booster. I’m sure some sharpness loss must be happening. It has to, but to the eye it just doesn’t show and the benefits it brings is just so huge. I’ve had no lockups at all with the adapter.


Only funny thing I found so far is the adapter makes the image stabilization jump when you scroll through the iris fast. Not a deal breaker but odd. It only did this with the 24-105. I didn’t notice this with the Canon 70-200. Another strange side effect is the iris shows f2.0 not 2.8 on the 70-200 and f2.8 not f4 on the Canon 24-105. The speed Booster does give you 1 stop more light but I don’t understand why the f-stop changes in the display. No big deal but it did surprise me. I actually got a good laugh seeing f2.8 with the Canon 24-105. That would be amazing on that lens!

Bob A7s

I needed some fresh BTS footage from the 4pm news cast for a promo that is going out to cable.  I shot one show with the Sony A7s and the Canon 24-105. The following week I had the new EF-MFT adapter so I decided to shoot with the GH4 in 4K with the awesome Canon 70-200 f2.8L II. Love that lens! I was pretty happy with the results from both cameras and in post they cut very well together. Only minor color correction was done.

Here are the camera settings I used.


  • Contrast o
  • Noise Reduction -5
  • Saturation -3
  • Hue +1


  • Gamma = CINE 2
  • Color Mode = PRO
  • Color Phase -2
  • Color Depth R +2
  • Yellow +2
  • Detail -3

4pm GH4

I feel really good about using these two cameras together. I only wish the A7s would record 4K internally. That would be so good. I’m feeling really comfortable shooting with both these cameras. In fact I’m enjoying it a lot. Having a good EVF is a big deal and mirrorless cameras are the way to go. I don’t think I could shoot from the LCD of a DSLR anymore. This is just to good.

Bridget A7s

News At 4pm GH4 wide

Next step is to get the Atomos Shogun up and running with the A7s and I need a couple cages too. Audio is pretty good internally with both cameras and I have to give the edge to the Sony A7s. It seems a little better. I might try out the XLR/Shotgun adapter Sony has but it’s pricy. If I had to choose only one I probably would take the GH4. It’s just a much better well rounded hybrid camera. Now I like the A7s a lot for video and I still need to see the 4K image from it but I stand my ground on a couple things I dont like. Lack of native lenses is an issue if you need auto focus you need fast native lenses. The A7s is really 90% video camera. If I need to shoot stills I’ll grab the GH4 every time. For the cost concise consumer the GH4 is a huge win over the A7s. For me I need both because the GH4 doesn’t perform very well in low light or settings over 1600 ISO. I’ll use the A7s for those situations.

So I’m sure you are think. Erik dont you have a C100? Are you keeping it? Are you moving over to these other cameras? For now lets just say it’s getting harder to justify keeping the C100. Audio is still an issue and I dont like duel system very much. I do feel I get every bit as good of an image from both these cameras as I get from the C100 with the exception of now having 4K for acquisition and thats a big deal on projects that might have a longer shelf life. We shall see but for now I’m having a blast playing with both these amazing cameras!

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Filed in: 4KA7sFeatured PostLensesMicro Four Third LensesMicro Four ThirdsMirrorlessPanasonicSonySpeed Booster
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About the Author ()

I'm a broadcast DP In San Diego. I enjoy sharing what I'm working on and testing new equipment. This blog is also part of giving back. I've learned so much from so many people.

Comments (13)

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  1. dale says:

    Thanks for this Erik. I have my C100. Still love it. You are starting to sway me though! I still have 10 months to go to pay off my beloved tho!!

    Blinkers on for a while longer!!!

  2. I’ve been quite happy with the Varavon Armor cage for my GH4. I’ve also shot 2 professional projects for using single system audio. The first one was with the GH3 and the latest with the GH4. The audio is noticeably lower quality when compared with a pro-recorder but I made the decision that it was going to be good enough for the purposes of my client and I was right. Obviously, YMMV but I’ve been able to shoot with a Rode VMP on one channel and a Sennheiser G2 wireless receiver on the other channel and control the levels enough from the transmitter/reciever and VMP independently. The VMP really needs a +10dB switch rather than just jumping from 0 to +20dB but in soft environments, +20dB won’t peak and gives me better StN however to play it safe, I usually leave it set at 0 and only rely on the VMP as an ambient mic.

    I hope manufacturers will put improved pre-amp audio circuit and level controls in mirror-less cameras in the future as well as built-in NDs (like the Fuji X100s). If I had those 2 things, it would simplify things tremendously.

  3. Rob Terry says:

    Great info and I love the color rendition of both cameras. On your GH4 settings, you list saturation twice, one at 0, and the other at -3, so what is the the right one? And what is missing?

  4. Nick Mercer says:

    What do you mean you don’t understand seeing f2.8 with your 24-105 f4 and f2 on your 70-200 2.8? That is the extra stop of light that you get from the speedbooster. If it did not show, you would be getting an inaccurate aperture value for your lens. Why are you listing that as a con? It’s a HUGE plus.

    • Nick Mercer says:

      In other words, your lenses are now f2 and f2.8 while using that adapter..

    • Erik Naso says:

      I understand what the adapter does. The aperture doesn’t actually open up more but the lens in the speed booster gives me 1 extra stop. Other lenses aren’t giving the camera a different fstop setting. It’s not a big deal.

      • Nick Mercer says:

        Which lenses aren’t displaying the additional stop? *Supported lenses should because without having that calculation displayed on the camera, most people will be over exposing by a stop. No, it isn’t opening your aperture blades up, but it still has to calculate for all of the light being gathered from a full frame lens to a M43 sensor.

  5. Aaron R says:

    Hi Erik,
    I have a C100 and GH4. I’m loving both right now, each for different reasons. But specifically the C100 for outdoor shooting. The dynamic range is so nice with fantastic roll-off in the highlights. My question is: how have you found the dynamic range to be with the GH4 and A7s in comparison?

    Also, I think the audio/sound options on the C100 are the best I’ve ever used on a camera. It’s so hard to decide if I should keep making those payments, or sell and see what’s coming around the corner. :-] It’s so hard being on a budget in this industry!

  6. Ivan says:

    Hi Erik,
    What did you do in post to match theses two? I’m testing for a multicam shoot and the footage seems quite different and perhaps post intensive to match.

  7. Michael says:

    Hi Eric,
    Like your contributions to the DSLR conversation. Keep up the good work.

    I wonder if you could give an opinion on the metabones adapter. I have a couple of GH4’s and the 12-35, 14-140 (new one), and a 25 mm1.8 prime that I use. I also have a couple of canon zooms. 24-105 IS and 70-200 f4 IS.

    I love the smaller lenses. One of my main motivations for getting rid of my 5D MK III was weight.

    I have been on the fence about selling my canon lenses and getting the metabones. Would I be missing out if I sold them? What’s your opinion? I am getting good results with my smaller lenses. Am I missing a lot without that S35 look?

  8. Phil says:

    Howdy Eric,

    I’ve got a GH4 with a metabones EF-M43 Speedbooster and a Sigma 18-35/f1.9 lens but I can’t get the iris to do anything in either “Creative Film Mode” (Yes, I’m in the Manual film mode) or “Manual” still mode. The iris is very small (f11) in the “Creative Film Mode” and wide open in “Manual” mode and spinning the aperture adjustment wheel does nothing. This combination seems to be quite popular on the blogs and chat boards so I am hoping that I’m doing something bonehead wrong and that I don’t have a hardware issue.

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