In the Field: Canon RF vs EF 24-70mm Lenses

Landscape photographer Jonas Hanspach compares the lens elements and performance of the RF and EF Canon lenses on his trip to Scotland.

Late last year, I made the move to the Canon EOS R6 mirrorless camera from my loyal companion, the Canon EOS 80D. As I didn’t have the newer lenses, I continued shooting with my old Canon EF 24-70mm f/4 L IS USM and EF 70-200mm f/4 L IS USM with the intention of upgrading to the newer RF lenses bit by bit. I was a bit sceptical about whether it would be worth the upgrade. I watched a lot of reviews on YouTube and the conclusion was always the same: the quality and sharpness of the RF lenses are incredible, so I wanted to try them myself.

With MPB, I had the opportunity to compare the Canon RF 24-70mm f/2.8 L IS with my existing EF 24-70mm f/4 L IS USM. As a travel and outdoor photographer, I wanted to know two things before I made the decision to upgrade. Is the RF 24-70mm f/2.8 L IS USM really that much sharper than my EF 24-70mm f/4 L IS USM? Is the wider aperture of the f/2.8 worth the extra money?

Image Stabilisation

There are a few things to note before I share my observations. This is by no means a scientific comparison of the two, but more of an in-the-field test. There’s also the option of the EF 24-70mm f/2.8 L II USM, but that one isn’t really an option for me as the earliest version of it was released in 2012, versus 2019 for the RF 24-70mm f/2.8 L IS USM. Fortunately, innovation in photography is slower compared to other industries. When I decide to upgrade my gear—which I don’t do often, and only after careful consideration—I want to have the best quality lens at the time of my purchase. On top of that, the EF 24-70mm 2.8/L II USM doesn’t have image stabilisation, which I rely on for shooting and filming in low light. Some of you might mention that’s what tripods are for, but I’m not a friend of them. I constantly move around in the field trying to find different compositions and a tripod may cause limitations for me.

With that out of the way, let’s dive into the review. First of all, I have to say the build quality of this lens is excellent. It feels good all around; the zoom and focus rings are super smooth and the third control ring is super handy for making quick adjustments to your exposure. 

Sharp Images

Is the RF 24-70mm f/2.8 L IS USM really that much sharper than my EF 24-70mm f/4 L IS USM? To assess this, I’ve taken a few comparison shots during a recent road trip through Scotland so you can see for yourself. Both pictures were taken with the exact same settings. I used a tripod for the below pictures and focused on the cottage.

From my point of view, the mountains in the background seem sharper. I also find the colours and contrast more pleasant with the RF 24-70mm f/2.8 L IS USM. The below shot of the Old Man of Storr really blew my mind in terms of sharpness. This picture is unedited and only converted from RAW to JPG. 

Judging by these images, it seems to me the sharpness is superior to that of the EF 24-70mm f/4 L IS USM when you put them side by side. However, I wouldn’t necessarily be able to tell the difference if they weren’t right next to each other. 

Wider Aperture and Light Performance

Is the wider aperture of the f/2.8 worth the extra money? This is where it gets really interesting for me. The extra sharpness alone would not be worth the upgrade in my opinion as you compress the images for websites or social media, losing some of that sharpness in the process. But combine it with the wider aperture and you’ve got yourself a pretty powerful and sharp allrounder. 

Throughout my entire stay in Scotland, I found myself changing lenses less often. This naturally speeded up my workflow and allowed me to not miss valuable moments. Naturally, I also got higher-quality photos in low-light situations without having to pump the ISO very much. The Bokeh is very good for travel and simple portrait shots. It is not comparable to an RF 85mm f/1.2 L prime lens, but it got me some sharp portraits with a decent background blur. Here are some shots at 35mm at f/4 and f/2.8 from the RF 24-70mm f/2.8L IS US vs the f/4 on the EF 24-70mm f/4 L IS USM.

And the same at 70mm. 

Canon RF vs EF Verdict: Is it worth the upgrade?

All in all, it’s a yes from me! Natural charges and contrast are superior to my EF 24-70mm f/4 L IS USM, and that’s worth a lot to me already. Coupling that with a nicer bokeh and the fact that I found myself changing lenses less and less really convinced me. The latter really disrupts my workflow, so the less I have to do it while retaining maximum image quality and getting the best shot of the landscape, the better. This lens does exactly that for me.

FAQs

Check out some of the most common questions about Canon RF and EF lenses, answered by the MPB team.

What does RF mean in Canon?

RF is Canon’s branded range of lenses made to fit their Canon R mirrorless cameras via the RF mount.The initials RF are short for Re-imagined Focus.

Can RF lenses be used on an EF mount?

RF lenses cannot be used on an EF mount as they are designed to connect to Canon’s R Mirrorless bodies via a 12-pin connection. EF lenses are designed to mount on Canon EOS SLR film and DSLR cameras, but can also be used with RF mounts via an adapter.

Are RF lenses sharper than EF lenses?

By design, RF lenses offer sharper performance compared to EF lenses. This is because EF lenses were designed to mount onto DSLR camera bodies. These camera bodies contain a mirror box with a mirror that flips up whenever an exposure is made. Effectively, the mirror has to get out of the way of the sensor to expose the shot, hence Digital Single Lens Reflex (DSLR). This means that in order to fit DSLR bodies, EF lenses had to be made with a degree of compromise so that the rearmost glass element of the lens wasn't too close to the imaging plane (sensor) so as not to be in the way of the flipping mirror.

As RF lenses are designed to mount onto mirrorless cameras bodies it means that they do not have to contend with a flipping mirror between the lens and the sensor. This means that RF lenses could be made with less compromise than EF lenses as the glass elements at the rear could be put 1mm away from the sensor. This design, in combination with advancements in technology since the DSLR era, means mirrorless RF lenses can deliver better edge-to-edge sharpness. This is especially evident in lenses from 35mm and wider.