Metabones EF-RF Speed Booster: non-scientific review

Superzoom2 wrote:

That's amazing! So other than the theoretical loss of quality through an additional element, the Metabones seems like a no brainer.

I was debating selling my R7 because I'm an occasional portrait photographer and I miss full frame. I'm hoping the quality of the Metabones is good enough for portraits if I use it with my primes on the R7. In particular, I hope it works well with my 35mm 1.4, my 50mm 1.8, my 85mm 1.8, and hopefully my 70-200 2.8 (all Canon, except the 85).

The loss of IQ on the Metabones Ultra Speed Booster is very minimal, but not quite purely theoretical. Still, it is very minimal. The Metabones Ultra seems to be widely regarded as the best speed booster available (based on the opinions I see online), with better IQ (and build quality) than Viltrox or other cheaper alternatives on other mounts (and the optics are the same).

The Metabones performs noticeably better than the Viltrox in all the comparisons I can see between these boosters. (And the Viltrox isn't available new in EF-RF for now too.)

I haven't seen a direct comparison of the Metabones with the (more expensive) Canon EF-RF speed booster, but the Canon one, as mentioned, doesn't have firmware support for the non-C70 cameras (and people seem to have quibbles with its purple flaring).

While the IQ of the optics is going to be quite good with the Metabones, your R7 will still not be a full-frame camera. Although you've shrunken the image circle down, your photosites are still smaller (and so your sensor still won't be quite as good in certain ways vs. a full-frame sensor). And you will have a 1.14x crop factor still, so your lenses (translating back to full-frame equivalency) will be like: 40mm f/1.6, 57mm f/2, 97mm f/2 and 80-230mm f/3.2. (Those will not be the APS-C equivalents, though, so don't get confused by that.)

Also, I have the 50mm f/1.8 and 70-200mm f/2.8 and they both work on this adapter so you should have no problems.