VILTROX EF-M2II 0.71x Speed Booster, EF to Micro 4/3 Focal Reducer Booster Adapter Auto-Focus for GH6 GH5M2 BMPCC 4K GH4 GH5 G100 G95 G85 OM-1 EM-1 E-M1X E-M1 iii E-M5 iii E-M10 iv E-M10 iii

This adapter is incredible for the money. However you will need to rotate the element inside the unit to achieve proper infinity focus. I had to update the firmware for it to work with the pocket 4K. Finally, do not use this adapter past the lenses advertises t stop. For example on the sigma 18/35, this adapter stays sharp all the way to f1.8, but when you use the “boosted” range of f1.2 to f1.8, it becomes a blurry mess. This is where the metabones is better. However it is way more expensive and if you’re happy doing the infinity focus tweak as well as using it within what the lens was designed for, you’re going to be extremely happy. Perfect pairing for the pocket 4K, as dropping the money on the metabones for the pocket 4K puts you at the same price as just getting a pocket 6k anyways.

This speed booster is very useful. Sold at more or less half the price than others, it delivers the same optical quality, good communication between the adapted lens and the camera and it has a very solid construction. I use it mainly with my Sigma 17-50mm f2,8 and my Tokina 12-24mm f4, both Canon EF mount, mounted to my Olympus E-M1 mark II. With this camera they become, respectively, a 24-70mm f2 FF equivalent (the Sigma) and a 19-36mm f2,8 FF equivalent (the Tokina). Focus is still very precise, even if slightly slower than when used on their original mount. Warning: in order to achieve a perfect focus you need to calibrate the speedbooster by phisically turning the optic group. It's very simple and there are lots of videos on youtube explaining the manouver in detail. 100% reccommended.

I tried this adapter with multiple cameras and lenses and each time the camera reads F- and autofocus doesn't work. I tried to update the adapter's firmware, but the drive came up completely empty, no firmware appeared to be installed in the first place. Following the online instructions for updating, I tried dragging the update files onto the adapter drive anyway. When I did, the adapter would not eject. When I unplugged and plugged back in, the drive was completely empty again. Also, the latch that locks the lens onto the adapter doesn't work. It's build so cheaply and it doesn't line up, so you can unscrew the lens without pressing the lever to unlock. Total piece of junk. I returned it and can't believe I paid over $200 what amounts to a junky passive adapter.

Mine came as a potentially returned or used unit. Because there's plenty of dust and visible smudge on both sides of the glass. Even though the packaging is still sealed. Either it was used or Viltrox's QC is trash. It was not too hard to get the dust and smudge out. Later, I went and upgraded the firmware. It was quick and without incident. Autofocus was much improved and aperture control from camera is enabled. After that, you need to adjust the infinity by rotating the glass element. My unit is way off. The autofocus is very usable for photography. I've tested 50 F1.4, 24-105 F4, 17-40 F4, 70-200 F2.8, 400 F4, and 100 Macro. They all worked fine. But the AF is completely unusable for video. It will either make loud noises with some lenses, or hunt repeatedly on a stationary subject, or fail to land on a proper focus, or all of the above. So expect to use MF for video shooting. After all, it's great for the price.

It’s hard to express just how much I love this speedbooster! Never had a problem with it and works great on my BMPCC 4K.

I purchased this to mount my Canon EF lenses to my LUMIX G7. So far I’m pretty happy with it. The build quality is pretty much all metal and seems solid. Autofocus, aperture control & EXIF all work fine. Autofocus is a bit sluggish, but that’s to be expected when adapting non-native glass to any system and not that big of a deal for stills. Definitely a great and cheaper alternative to Metabones. Image quality is good and fairly sharp at about f/2 and up, anything lower gets soft but they’re still reasonably exceptable. It mounts great to the G7 snuggly and lenses mount nicely too with out any issues.

Using this on the BMPCC 4K, not only is the connection to the camera loose, but the connection to EF lenses is too. When I rack focus, there is a noticeable jitter in the image due to the lens shifting back and forth. I have not tested the auto-focus so photo lenses might work better, but I would not recommend this for cine lenses.

When it works, it’s great. I moved from Canon to an OM-1 MkII but I hated to give up my favorite Canon macro lens, the 180mm f/3.5L. I bought this in hope that I could still use it on my new camera, as it was on the list of compatible lenses. I was able to get a couple of shots off before my camera screen went black. I kept having to turn the camera on and off in order to make it work, and sometimes multiple times. Definitely not conducive to an enjoyable shooting experience so I returned it. Side note: I ended up buying a full-frame Canon RP and an EF to R lens adapter which was cheaper than buying an Olympus macro lens!

This really works and I have no idea how Metabones can be even better. Best benefit for the price. It worked neatly with my Sigma 18-25mm.

Panasonic GH6にEF－Sレンズを使用する為に購入しました。 まず同様の商品を複数所持していますが、正常に動作するものはごく僅かです。 この商品もズームを操作したとたん認識が外れることがあります、接触が悪いことが無ければ基本動作は可能であろうと思います。 AF-Sにおいては基本的には問題なく、一部の暗いズームレンズでフォーカスがズレる現象が見られました。 AF-Cは動作しようとするのですが動作しないようです。 F値はいい加減な表示をします、ファインダーと仕上がりが違うことがあります。

quick reliable and great value

一度目の購入：OM-1のカメラ本体には装着できるが、EFレンズが装着できない。アダプターの赤点にレンズ赤点を合わせ右に回すが、少し行くと止まってしまう。何度やっても同様。別のEFレンズでもトライしたが、同様。初期不良と判断し、返却して返金となった。 二度目購入：一台目が初期不良と判断したが、どうしても使用したいと思い二度目の購入。しかし状況は同様。一度だけ本当に無理やり回し何とかカチッとなった（装着できた）。AFも絞りも正常に働いた。…が、やはり装着のこの固さは尋常ではない。もう一度装着しなおしてみたが、レンズフードが壊れてしまうのでは？というほど力を入れてようやく装着できた。レンズ交換ができる一眼が野外でこれではとても使えない。この仕様なんだろうと判断し、二度目の返却となった。 実はこのVILTROX社のストロボ（以前のもの）がとても気に入っていて、７台リピート買いしていたもので、この商品には期待していた。残念だった。しっかり装着ができれば、もっと試撮したかったが、そこまで行くことができなかった。

Good