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Review Viltrox EF-M2 AF Speed Test @ 17mm

Discussion in 'Reviews, Tests, & Shootouts' started by ed9e, Feb 14, 2019.

  1. ed9e

    ed9e New to Mu-43

    Feb 11, 2019
    I'm using Viltrox EF-M2 adapter for a year already and I like it. It has compatibility issues, but when it works, it works great. With this test I wanted to show you just how good Viltrox adapter works with certain lenses and bodies, and what compatibility issues look like. Hence the video aimed primarily at testing AF speed and accuracy, all lens set to 17mm.

    - three generations of Olympus cameras, E-P5 (TruePic 6 processor), E-M1 (TruePic 7) and E-M10.3 (latest TruePic 8)
    - native mZD 17/1.8 lens
    - Canon EF 16-35/2.8 L II USM, EF 24-105/4.0 L IS USM, EF-S 10-18/4.5-5.6 IS STM
    - Sigma 18-35/1.8 DC HSM Art
    - Viltrox EF-M2 speedbooster with latest ver.3.2 firmware and Viltrox EF-M1 plain adapter for EF-S 10-18 lens

    1. mZD 17/1.8 is the quickest to focus at 0.14-0.15 sec on average. That was expected. What I did not expect, though, was the fact that all three generations of Olympus cameras AF this lens with the same speed. Strange, I thought Olympus improved S-AF speed in latest generation cameras equipped with TruePic 8 processor. My test shows otherwise.

    mZD 17/1.8 is also the loudest to AF in my test. This is probably due to aperture closing for framing and quickly opening for AF, but the sound is just too loud.

    2. Canon EF-S 10-18/4.5-5.6 IS STM was a pleasant surprise. I tested it on plain Viltrox EF-M1 adapter since I could not modify this lens for speedbooster. The lens worked fine on all three Olympus cameras. It was very quick on E-M1 and E-M10.3 taking 0.23-0.24 sec to focus on average. E-P5 AF was OK at 0.34. AF accuracy was excellent which it should be at f/5.4 :) 

    The best part of AF was the sound, or rather lack of any sound during AF. STM motor was a very pleasant surprise.

    3. Canon EF 16-35/2.8 L II USM worked fine only with old E-P5. Despite only CDAF, E-P5 was able to AF this lens taking only 0.17 sec on average. Excellent speed! AF accuracy was also good.

    E-M1 was somewhat slow to focus this lens at avg. 0.37 sec. Worse still, it sometimes hunted for focus for 1 - 1.5 seconds. AF was accurate.

    E-M10.3 performance with this lens is a mixed bag. On one hand, AF is very quick and accurate for near objects. On the other hand, AF failed to lock focus on distant targets, trying to hit well beyond infinity mark. I would use this combo indoors, probably, but for distant objects you are left with manual focus only.

    4. I had high hopes for Canon EF 24-105/4.0 L IS USM. I like this lens build without too much bulk, sharpness and constant aperture. It might be a good walkaround lens with speedbooster, but alas it has severe compatibility issues.

    AF speed is reasonable with near objects at 0.25-0.33 sec. But AF with distant targets is unavailable. Only E-M1 was able to lock focus on distant object, but it did so with apparent front-focus.

    5. Sigma 18-35/1.8 DC HSM Art performed very well with E-P5, taking only 0.22 sec on average to lock focus. It is very good considering the large f/1.2 aperture of the lens on speedbooster. AF accuracy is excellent.

    E-M1 was slow to AF this lens at 0.43 sec. AF accuracy is good.

    E-M10.3 was even quicker than E-P5 to AF the lens. But E-M10.3 struggled to lock focus on distant target. It allowed to make a shot of distant object but with slight AF overshooting to backfocus.

    Sigma 18-35/1.8 focuses with loud metallic clicks. Strange for an ultrasonic piezo drive focus motor. AF noise probably renders this lens AF unusable for video with on-camera mic.

    Overall, Viltrox adapter has its compatibility issues. It is usable with those issues, though. And when it works well, like E-P5 + Sigma 18-35, it is a genuine pleasure to use.
    Last edited: Feb 14, 2019
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  2. ibd

    ibd Mu-43 Veteran

    Jun 5, 2016
    Great video, very thorough! Very informative for people looking for lenses / lens combinations around that focal length!
    I too have the EF-M2 and the 10-18mm EF-S lens, modified it.
    Occasionally it will miss focus or strangely "freeze" the focus for a few shutter presses before it works again. That's on a Panasonic GX85. Did you encounter any problems like that with the EF-M1 and your Olympus cameras?
    • Like Like x 1
  3. ed9e

    ed9e New to Mu-43

    Feb 11, 2019
    Thanks! :) 

    I only had 10-18 for couple of hours. I did not encounter any problems with my Olympus cameras. I did not modify it and used it only with EF-M1 adapter. 10-18 may have compatibility issues with EF-M2 speedbooster, I just don’t know.

    I am not really interested in this lens either, because I have Sigma EF-S 8-16/4.5-5.6 HSM. That lens is much wider than 10-18, with speedbooster it is the widest rectilinear lens available for m4/3, producing close to 11mm equiv. focus length. Difference with 7mm lenses, 14mm equiv. (like native 7-14 or EF-S 10-18 on a speedbooster) is significant.

    Sigma 8-16 is so wide with speedbooster, you get top and bottom lens hood petals in the frame shooting at native 4:3 ratio :)  This is not the case when shooting in 3:2 ratio that is native for the lens.

    The lens with EF-M2 speedbooster has also a small issue with aperture: the biggest available aperture is reported to camera as f/3.2 regardles of focal length. But the lens is not constant aperture and shooting at f/3.2 at tele side of the zoom gets an underexposed image. Aperture value should be dialed manually when not shooting at widest, or exposure should be compensated +0.7 EV. A small issue.

    The lens on speedbooster works fine with E-P5. E-M1 focusing speed is low. And E-M10.3 cannot AF the lens in the range from 8 to 10mm per lens scale (6 to 7mm as reported on camera screen), but focuses just fine after 10mm mark.

    The lens is sharp, it has noticeable distortion and vignetting, but acceptable to my standrards.

    Overall, I consider this lens the best ultrawide lens for m4/3.
    Last edited: Feb 15, 2019
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  4. SoulRebel

    SoulRebel New to Mu-43 Subscribing Member

    Sep 27, 2018
    London, UK
    Excellent stuff, and entirely share your assessment of the Viltrox adapters - when they work, they work great.

    My experience is with two Sigma lenses, the 17-50mm f/2.8 and the 50-150mm f/2.8. Both AF quickly and accurately on my E-M5ii, and much more slowly on the E-M1 (not unlike the 18-35mm in your video). The advantage is that I get affordable f/2.0 zooms not available natively at very usable focal lengths for me. Have been thinking about getting the 18-35 to get some wide and fast zoom capacity, would be cheaper than getting the Olympus PRO 17 and 25mm primes.

    Have only tried one EF-S lens, the 55-250mm IS STM. This does focus on the E-M1 but slowly, doesn't autofocus at all on the E-M5ii, and is very fast and accurate on the E-M10ii. All with the EF-M1 as I could not modify the lens to make it fit the focal reducer.

    Had a very short experiment with the EF 100mm f/2, would not focus properly at all on any of my cameras, am inclined to think that that was a lens issue. Also have the older 135mm f/2.8 SF, which works well on all cameras and very sharp but is very noisy to use.

    I wonder about trying out the Metabones Speedboosters as they are considered to be the standard, but as I can pick up several EF-M2s for the cost of one Metabones....given how well they work, it's a no-brainer as I can attach one to each lens I adapt and that will be maybe four of five lenses in all out of my collection. As you say, a genuine pleasure to use.
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  5. bikerhiker

    bikerhiker Mu-43 Hall of Famer

    Dec 24, 2013
    Do you have to modify the Sigma 18-35 to work with the Viltrox EF-M2? I'm actually interested because with this lens, I will have 3 of my most used focal lengths @ f/1.2.

  6. ed9e

    ed9e New to Mu-43

    Feb 11, 2019
    No modification is required to work with speedbooster EF-M2. Sigma 18-35 is made to EF standard, so no protruding parts in the back of the lens as in EF-S standard.

    I guess only Canon makes lenses with protruding parts as allowed in EF-S standard, all third-party manufacturers use original EF specification even for APS-C lenses. All third-party lenses should be compatible with speedbooster without modification, at least I haven’t heard of any incompatible third-party lens yet.
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  7. Christop82

    Christop82 Mu-43 All-Pro Subscribing Member

    Sep 10, 2016
    I just received my new to me gx85 yesterday and tried the EF 100mm f2 on the viltrox. AF was reasonably fast and accurate. I think the aperture displayed f1.4 wide open which sounds about right. This lens also focuses well on the a7ii with sigma mc-11 adapter.
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  8. SoulRebel

    SoulRebel New to Mu-43 Subscribing Member

    Sep 27, 2018
    London, UK
    Sounds good, can remember getting something like 71mm f/1.4 with the EF-M2 on my EM5ii and EM1.1. Was a shame that my copy never worked out, everything I'd read about the lens suggested it would be a good performer but it wasn't for me.

    Since then I've bought the Sigma 56mm f/1.4, and if I add the old B300 teleconverter (same thread size as the lens) I get a 94mm-ish f/1.4,whch kinda makes up for the loss of the Canon.
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