An attempt to solve the price/focal length dilemma: Metabones T Smart adapter + Canon 70-300mm IS II

There are a number of disussions about adapting EF lenses to m43 using the Metabones adapters, but most of them are about the speedbooster, not about the T smart model (without lenses). Obviously, if you go for more reach, you don't want to reduce your focal length.

I was looking for a longer tele zoom, but didn't want to pay the price of the Pana Leica 100-400mm, even less so because the reviews were mixed concerning IQ at 300-400mm range. Likewise, the Olympus m.zuiko 75-300mm is said to suffer from quality issues at the long end. So my idea was to adapt the latest version of the Canon IS USM, which had got quite good reviews. The IQ is said to be closer to the 70-300mm L than to the low cost Canon alternatives, and it is still reasonably fast (faster than the m.zuiko 75-300mm or the Panasonic 100-300mm). I compare it to what I have, the 40-150mm Pro + MC-14 (210mm max focal length, but often a bit too short for me). A point in favour of the Metabones+Canon option was that I got the adapter at a good price, there is 80€ Cashback for the Canon this summer, plus the possibility to use other EF lenses.

My criteria were the following: If the adapted Canon delivered good quality at the long end, and if it had a usable AF, I'd keep it. My plan was to also compare it to the m.zuiko 75-300, but I didn't get it soon enough. The adapter and the Canon arrived first, so I tried

- Olympus E-M1 Mark II FW2.1
- Metabones T Smart Adapter Canon EF - M43 FW3.0 (MB_EF-m43-BT2)
- Canon 70-300mm f4.0-5.6 IS II USM
- Olympus 40-150mm f2.8 Pro + MC-14 (= 56-210mm f4.0)

To cut a long story short, even the first tests showed that the second criterion was not satisfied: the AF performance was not good enough to keep it. I want to share some of my impressions:

**General impression**

- The Metabones was already shipped with the lates Firmware 3.0. No update needed.
- Build quality is good. The adapter fits well on the camera.
- The Canon lens, however, could be more firmly seated on the adapter. There is no play between the two, but the lens moves a franction of a millimetre around the longitudinal axis, with a clicking noise. This wouldn't be a problem for me, and it's hard to tell if it's the 'fault' of the lens or of the adapter.
- The combination of adapter and lens goes well with the camera. Compared to the Olympus 40-150mm PRO + MC-14, the weight and dimensions are almost identical: 900g, 170x80mm (apart from the fact that the tube of the Canon extends the length considerably above 70mm). The Canon is made of plastic, but well built and pleasant to use, with smoothly operating zoom and focus rings.

**Function**

- As specified, the adapter transmits the relevant data (f-stop, focal length) to the camera and to the EXIF data, so no problem there. Exposure modes A, S, M, P etc. function just as with a native lens.
- AF is functional, but as I said above, it is too slow for my liking. I tested it in good conditions, and AF delays might be acceptable for some users if the distance doesn't differ too much. But as you well know, in many situations the difference is more important: you aim the branch with the bird while the lens is on infinity, flying birds, approaching subjects etc. etc. I try to describe more in detail what happens (or doesn't happen):

• For a big focus shift, from ~2m to infinity, be prepared to wait about 1.5s (a bit less at 70mm, rather 2s at 300mm) for the AF to lock, in good conditions, e.g. edges with good contrast (moving from the window frame to dark trees on the horizon). There is not much focus hunting back and forth, and the motor is almost silent, it is just slow. Unbearably slow compared to the Olympus PRO+MC14, which locks AF almost instantaneously in the same situation. I didn't expect the adapted lens to perform similarly, but in 1.5 secs I can easily focus manually. So there is no point in spending so much on the Metabones adapter.
• In less optimal conditions AF is worse: at 200-300mm, if you shift to a nearby target without contrast edges (a branch of a tree, or a bird in a tree other than a swan), the AF won't lock. Never. The lens display tells you it hunts for a bit, than AF activity simply stops.
• Sometimes, and less systematically, hard to describe why, even in good conditions, AF won't lock (no green focus frame), and if you preset for focus priority, you can't shoot. Even lifting your finger and refocusing won't work.
• There were some postive surprises (compared to what I found out from previous reviews):
  • The lens focuses almost silently (it seemst that the Mark II received a new nano USM motor).
  • ProCapture is supported with this combo (although focus bracketing isn't). Once your focus is locked on the subject this feature might be interesting, regardless of the slow AF performance.-
  • -AF works, but is also slow (unsurprisingly). I think the Metabones documentation recommends not to use C-AF anyway.
  • Manual focus with automatic magnification (e.g. in S-AF+MF mode) also works. But I suppose you don't want to buy the Metabones adapter if you go for manual focusing anyway.

The result is that the insufficient AF performance made me return the lens, and that is why I didn't go deeper into comparing the IQ. I just took some real-world shots with Canon combo and the Oly PRO+MC14, and I share my impressions because they might be interesting for those of you who don't care about AF performance or who wish to combine the lens with a cheaper, manual adapter. My setup was: tripod, IS off, ISO 200, LSF JPEG, colour natural, 70-135-210(-300mm), f5.6 (plus f4.0 at 70mm), AF with small focus field fixed on the first pillar at the right of the tree, on the parking deck level of the building.

- Up to 210mm Oly is sharper, but I guess not many will notice it at normal viewing distance (I don't print larger than A2).
- At 300mm Canon is better than Oly cropped.
- At all focal lenghts, CA with Canon is considerably stronger (maybe rather not corrected versus well corrected for the Oly combo).

Bottom line: the adapted Canon 70-300mm is a good tele zoom lens for m43. It is certainly an alternative to the m.zuiko 75-300mm. It is not for those who need a fast AF. If you are ok with a slow AF, the Metabones T Smart adapter is a comfortable but expensive solution. With a cheaper adapter, the Canon gives you the better IQ than the m.zuiko at a similar price.

Canon 70-300 + Metabones vs Olympus 40-150 + MC-14

Canon combo 70mm

Olympus combo 70mm

Screenshot 1:

Screenshot 2:

Screenshot 3:

f5.6 left margin: Oly left 210mm - Canon right 300mm

jwilliams wrote:

a Canon 55-250 IS STM might work better. I just got a Viltrox adapter and already had the lens. Haven't used it a lot, but initial test seem to indicate pretty good IQ. AF while not blazing seems decently fast and sure. Since the lens is optimized for APSC it might actually resolve more per mm than the FF lens.

I'm a little surprised AF is so slow. I've seen a video using that lens on a Canon camera in live view following a go cart around a track. Of course the Canon has the DPAF so apparently that makes a huge difference. Still I think it would work pretty good on a mirrorless as the Nano USM is really meant for cameras that use live view and video. Maybe the STM lenses are faster for some reason. Both types are intended for LV and video use.

Thank you, Jonathan. The 55-250 is too close to the focal lenght I already have, but I will give the Viltrox a try if I manage to find one.

I also was surprised by the slow AF, even more so since the 70-300mm I had tried was on the list of supported lenses with 'accurate' AF Lens Compatibility.

Pierre

tomhongkong wrote:

Don't rule out the Olympus 75-300 too quickly. See some samples I posted a few days ago. If they are really not good enough for you, fine, but for most purposes they work for me (you just have to live with f6.7 at the long end)

tom

Thank you. In fact someone will lend me the Olympus 75-300 and I'll be happy to try it and to share my thoughts (I won't be able to compare it with the Canon-Metabones combo though).

Pierre