Canon 100mm Macro USM EF Lens w/Sigma MC-11 on Sony Alpha A7Riii
So the hardware employed in this review:
- Sony Alpha A7Riii
- Sigma MC-11 EF to E Adapter
- Canon 100mm Macro USM EF Lens
So as noted from the preview post, my brother lent me his Canon 100mm Macro USM EF lens, to use with the Sigma MC-11 adapter on my Sony A7Riii.
The first couple of days I was using the lens, I found that the autofocus worked really well in a variety of lighting situations.

The lens produced amazing detail and focused very quietly, thanks to the ultra sonic motor in the lens. The f/2.8 aperture allowed in plenty of light, which allowed snappy AF performance. Both phase detect and contrast detection worked well on the A7Riii, though I occasionally had some issues with the AF engaging. More on this below.
It goes without saying that I love my cats and I love being able to take close up photographs of them! However, they have learned to listen for the sounds of a camera shutter or screw drive lens, so it is hard to get them to sit still or stay put when using a setup that makes too much noise. Thankfully, the lens was very quiet(not-silent) and the A7Riii was in silent shooting mode, so the whole process drew very little attention from the kitties.

Sometimes, I like trying it without color. Conversion done in CaptureOne11.

However, this is a macro lens, so I wanted to give it some subjects that actually provided some macro situations and produce some macro shots. I took the lens and camera combo out to the greenery patches in the parking lot and had at it for a bit.
A bit of a closeup, a pine cone after the rain. Here, I really wished I had more depth of field, but we’re talking 100mm at f/2.8… Still, nice bokeh elements(no match for the 135mm/1.8 or the 135/stf though…)

But let’s get nice and close with some dropped things on the ground… so glad for the flip screen. My back and knee is very appreciative….
First up, a simple burr I found amongst the ground cover. Looks so different when up close.

Next up, there were some remnants of seeds or seed clusters on the ground…


I’ve got to say, I really enjoyed shooting with this lens. It’s a good size, is dead-on sharp when auto-focusing, and works with many of the A7Riii’s AF modes and features.
However, there are some gotchas. So let’s end on the following notes until the next/last part of this post.
Pros:
- 100mm and 6″ minimum focusing distance = great macro lens.
- AF mechanism is VERY quiet and very quick/accurate.
- Lens produces images with great detail.
- Can be had for a relatively cheap price on Ebay.
- Supports AF-S and AF-C focusing modes as well as Face Detection, EyeAF, Phase Detect, and Contrast Detection focusing modes.
- Lens data is stored in the images’s exif data… but not all tools will pick it up and use it. CaptureOne11 didn’t capture it correctly, but exiftool did.
- USM, or electrically driven focusing motor vs screw drive!
Cons:
- The AF mechanism has issues if the AF is not focused on something and the actual desired plane of focus is too distant from the current plane of focus. 🙁 This is an issue regardless of focusing mode or focusing sensors used.
- The AF is snappy, but not as snappy as a native E-mount lens.
- The plastic construction and ever so slight play is a bit worrisome.
- Requires an adapter… but the same can be said of A-mount lenses.
- Depending on your photo software, the lens might read as a DT 100mm lens. 🙁 Even though the Canon lens details are in the file.
Still got a few days to shoot with the lens and get a better sense of what I like and don’t like about it. So please look forward to the next post. In the meantime, I’ve purchased a copy of the lens for my own use, so once I return this one back to my brother, I’ll still have a very nice 100mm macro lens.