With the popularity of mirrorless cameras from Sony, Fuji, Panasonic among others, more and more Canon users are either changing systems or wanting to try these new cameras. That in turn, is making adapting lenses more popular than ever, especially as autofocus performance continues to improve and includes many native features like Continous Eye AF (in the case of Sony cameras).
While I was never a Canon DSLR owner, I have purchased Canon EF lenses before to use with my Sony camera because either there was no native option at the time or the Canon offering was superior in image quality for my needs.
My experience has been that results vary from great to terrible depending on the particular lens, camera body, and firmware being used.
But one question did remain after using adapters: do they affect image quality even though they do not have any glass elements?
While using the Metabones IV before, I did notice problems with image sharpness on the edges of my wide angle lenses, but I thought it was just a particular lens defect of my copy or the fact that it was not designed for the mirrorless sensor of my Sony cameras.
After getting the $399 Metabones V and $249 Sigma MC-11 adapter, I was using them with my different lenses randomly until I started noticing a pattern. While the Metabones was giving me results similar to IV, the MC-11 was always giving me much better sharpness across the frame from my wide lenses.
The lens being tested is the widest I could find in other to really put this theory to the test: the Canon EF 11-24mm f/4.
For every adapter or lens, 10 photos were taken to make sure my results were consistent and not based on a few bad photos. You can also download the RAW files so you can inspect them on your end if you so desire.
On these 100% left side crops you can clearly see how much more detailed the MC-11 sample looks:
The sign where it says Welcome to ED’s Place, for example, is a lot sharper with the MC-11 than with the Metabones.
Once again, remember that for every adapter or lens I took 10 photos not just 1, so what you are seeing here is not a single bad photo of the Metabones but the consistent results I got from it during the tests.
The FE 12-24mm does very nice on the left side too.
Here are 100% right side crops:
On the 100% right side crops once again you can see the superior sharpness offered by the MC-11 like on the power lines and post near the top right corner. The Metabones looks blurry and seems to be affected by vignetting as well.
My FE 12-24mm has a weak right side which you can see on the drop in sharpness compared to the left side test.
For test 2, I decided to include the Canon 5D Mark IV as well for reference.
For comparing 100% crops of the left side of the frame, I reduced the size of the a7R III images to match the resolution of the Canon 5D IV. This makes the comparison between the MC-11 and Metabones look a bit closer in performance than it really was. Feel free to download the full-size photos so you can compare on your end as well.
You can see that the MC-11 shows the 45 parking sign with more detail than the Metabones. Also, the Bestway sign is sharper as well.
The FE 12-24mm does very well on this left side with great detail while the Canon image lacks detail in comparison to the others.
For the right side 100% crop samples, I did not resize the a7R III images to match the Canon.
Once again the weak right side of my FE 12-24mm shows in the blurry sign “Classic Cars”. The Canon 5D, as on the previous crop, lacks the details to compete with the other samples.
And like in all other previous comparisons, the MC-11 easily beats the Metabones in detail with the best detail on that “Classic Cars” sign. It really is like comparing different lenses when looking at the MC-11 and Metabones images with this particular lens!
In summary, from my tests, all I can say is that the Sigma MC-11 is my choice for adapting wide angle lenses as it gives the best performance across the frame.
Please note that for different lenses, autofocus performance may vary depending on the adapter and camera you are using so do not take this article as a recommendation to always pick one adapter over the other in terms of autofocus. This test was specifically about sharpness across the frame for wide angle lenses.
While my experience with the Metabones V is similar to what I saw with my previous Metabones IV, I still decided to contact Metabones support about this to see if they want to provide another adapter for re-test or can offer an explanation for this behavior. I have read about users shimming their adapters to correct for similar issues, so is this a manufacturing problem with some Metabones adapters or a design issue with all of them?
I am hoping to hear from their tech support soon so I can update the article, but in the meantime, I will stick to the MC-11 for wide angle lenses.
About the author: Luis Gabriel Gerena is a Utah-based portrait photographer. The opinions expressed in this article are solely those of the author. You can find more of his work on his website, YouTube, Facebook, and Instagram.