Using Sigma EF Lenses on Canon Mirrorless Cameras (R5 & R3) – Real World Experience


Hey everyone, I’m Tim — a wedding and lifestyle photographer based in Ontario, Canada. In this post, I want to dive into a topic I’m frequently asked about: how do Sigma EF-mount lenses perform on Canon’s modern mirrorless cameras, like the Canon R5 and R3?

If you’ve been holding onto your EF glass and wondering if it’s still usable on the latest mirrorless bodies, this post is for you.


Adapting EF Glass to RF Cameras


To use EF lenses on Canon mirrorless bodies like the R5 or R3, you’ll need an EF-RF adapter. The one I’m using is Canon’s official adapter with a control ring. It’s weather-sealed, has a solid rubber gasket, and overall feels extremely well built. You can also find third-party adapters, but for professional work, I recommend sticking with Canon’s version for maximum reliability.


Autofocus Performance


One of the biggest concerns is autofocus — and I’m happy to report that in photo mode, the Sigma EF lenses perform surprisingly well. I tested the Sigma 85mm f/1.4 Art, Sigma 40mm f/1.4 Art, Sigma 24-70mm f/2.8 Art, Sigma 70-200mm f/2.8 Sport and the Sigma 120-300mm f2.8 Sport, and all locked on quickly using eye-detection AF. Tracking performance was very solid, especially for portraits and general lifestyle shots.

In video mode, performance remains strong, though you might notice slightly slower acquisition in tricky lighting or backlit scenes. It’s absolutely usable for weddings, events, and documentary-style shooting — which is where I spend most of my time.


Image Quality & Lens Behavior


These Sigma Art lenses still deliver sharp, contrast-rich images with beautiful color — even on the high-resolution R5 and the fast-tracking R3.

However, there are a few quirks to note:

Occasional hunting in lower light situations

Firmware: Make sure your lens firmware is up to date. Some older Sigma lenses may have issues with newer Canon bodies if not updated.

Despite that, these lenses are incredibly usable. For anyone transitioning from DSLR to mirrorless, they’re a cost-effective way to keep shooting without jumping straight into expensive RF glass.


Should You Keep Your Sigma EF Lenses?


Absolutely — especially if you’re budget-conscious or already invested in the Sigma Art lineup. Here are the pros and cons I’ve noticed:

Pros:

  • You save money by keeping existing glass
  • No loss in image quality
  • Autofocus is more than capable for professional work
  • Autofocus is faster than a DSLR camera

Cons:

  • Slightly slower AF vs. native RF lenses
  • Adapter adds a bit of bulk
  • Occasional quirks, depending on your lens model
  • Sigma Lenses can be heavy


Final Thoughts


If you're a full-time photographer like me — with video reserved just for YouTube content — using Sigma EF lenses on Canon’s mirrorless R system still makes a lot of sense in 2025. The autofocus is fast and reliable in photo mode, image quality is sharp and clean, and the lenses work seamlessly with Canon's EF-RF adapter.

For my everyday work as a wedding and lifestyle photographer, these lenses have never let me down. And when I do create behind-the-scenes or gear-focused content for YouTube, they still perform well enough for that too.

If you already own Sigma EF glass, don’t feel pressured to jump into RF lenses right away. You can absolutely keep creating high-quality images — and content — with what you’ve got.


Have questions or want to share your experience using EF lenses on RF bodies? Drop a comment or reach out to me on Instagram @timgowlingphotography.