What is the difference between Canon EF and RF lenses? In this post I’ll help you understand the differences between some of Canon’s EF and RF L series zoom lenses.
General differences between RF and EF lenses
The one universal fact of all current RF and EF lenses is that all the RF lenses are newer, in some cases much newer than their EF counterparts. This doesn’t mean that EF lenses are inferior across the board but it does generally indicate that RF lenses will be improved over their EF counterparts. I have been reading a lot of reviews about various lenses in the EF and RF ecosystem, and I have personally tried different lenses in both systems and as a general rule I would say that RF lenses are superior to their EF counterparts in terms of their optical performance, their autofocus performance, and their stabilization performance.
There are also physical differences between RF and EF lenses which makes them non-native to each other’s systems. EF lenses can be adapted to RF cameras with the use of an RF to EF adapter. RF lenses can’t be adapted to EF cameras.
Canon RF 24-70mm f/2.8 L IS Vs. Canon EF 24-70mm f/2.8 L
Historically, 24-70mm f/2.8 zoom lenses are a staple for many photographers, especially professionals. It has a relatively fast aperture of f/2.8, and it maintains a constant f/2.8 no matter the focal length. For about 20 years it has been regarded as a must have lens as part of the f/2.8 “trinity” of lenses.
The EF 24-70mm f/2.8 L mk II is a very good lens and it received a lot of praise when it was released in 2012. It is a 10+ year old design but is good enough to still be a legitimate option for current generation RF and EF cameras.
The RF 24-70mm f/2.8 L IS is a new design that features optical stabilization. While many people will say that IBIS is good enough for stabilization, optical stabilization is still a powerful addition, especially when it comes to hand held video. When a camera with IBIS is combined with a lens with OIS, then the stabilization effect is increased further, allowing for extremely long hand held exposures and very stable video footage.
The RF and EF versions of these lenses are optically near the same level. The addition of stabilization in the RF version makes it a better option for low light photography or photography that captures movement in the scene with longer exposures.
EF 24-70mm f/2.8 L remains a great, although slightly outdated lens, and the new RF lens is even better thanks to the addition of OIS and the continuation of excellent optical performance.
Canon RF 15-35mm f/2.8 L Vs. Canon EF 16-35mm f/2.8 L mk III
In this case the two lenses perform very well, and nearly equally. The EF 16-35mm mk III was released in 2016 so it is one of the newest lenses in the EF system. Despite it’s impressive image quality, the new RF 15-35mm f/2.8 L is generally regarded as being optically superior. It obviously zooms out one extra millimeter in focal length, which is equivalent to a 3.5 degree increase in the diagonal field of view. While that may seem small, it is a substantial increase in the size of the total scene frame. It also puts the RF 15-35mm firmly into ultra-wide angle lens territory. It will be wide enough that many photographers looking at a 11-24mm or 10-24mm style lens may find that the 15-35mm is an overall better choice.
One minor downside of the RF 15-35mm is increased distortion at the wide end of the zoom range. This isn’t a problem for digital photography 99% of the time, but for film photography it might be an issue depending on how you like to work. (There currently is no film camera for RF lenses.) The EF 16-35mm f/2.8 L III is lower distortion throughout it’s range which makes it usable on EF film cameras where no digital corrections are possible in camera.
I own the EF 16-35mm f/2.8 L mk III and it is a very good lens but not a perfect lens. However, if one avoids pixel peeping and simply focuses on the overall image, I think it is a great lens and can take beautiful pictures.
Between these two wide angle zoom lenses it’s a much more difficult call as to which one is better. Being totally objective, the RF 15-35mm f/2.8 L is likely superior in the field. Canon has improved lens coatings, improved autofocus, and improved stabilization performance for all the RF L class lenses. This is partially down to the cameras but in my experience RF lenses are usually at least a little faster and more reliable with focus acquisition.
Canon RF 100-500mm f/4.5-7.1 L Vs. Canon 100-400mm f/4.5-f/5.6 L mk II
This focal range has been popular for Canon ever since they released the original 100-400mm lens. Many people enjoy the old EF lens, but the newer 100-500mm creates a high quality image. I have read odd anecdotes here and there of certain users preferring the 100-400mm, or complaining about the smaller max aperture of f/7.1 (at 500mm) on the new 100-500mm. These are legitimate complaints but with long telephotos I think the name of the game is resolution retrieval and at that the RF 100-500mm wins. Of course, simply comparing 500mm to 400mm the new lens will pull out more details than the old lens. If the question is simply which lens gets more detail? The answer to that is that the new RF 100-500mm does.
Where the EF 100-400mm steals a victory is opening up to f/5.6 at 400mm. The RF 100-500mm is at f/6.3 at 400mm, and f/7.1 at 500mm. That said, the RF 100-500mm has a slightly closer MFD at 500mm, most likely it will be possible to get a slightly bigger background blur with the RF 100-500.
There are some minor downsides to the RF 100-500mm lens. One of these is how it behaves when used with teleconverters. It does work with 1.4x and 2.0x RF teleconverters but the zoom range will be limited in both cases. With the 1.4x it becomes a 420-700mm lens, and with the 2x it becomes a 600-1000mm lens. It would be nice to end up with a 200-1000mm after adding the 2x converter. The EF 100-400mm will work with EF teleconverters but it won’t restrict the range like the RF version does. So if you use a 2x converter on the EF 100-400mm you will have the full 200-800mm range to work with. On paper that’s better than the 420-700mm range the RF 100-500mm gives with the 1.4x converter.
Another consideration here is that the older lens is substantially cheaper. Usually around $800 USD less money. When it comes to value per dollar, the old lens may just sneak away with a victory.
It’s a tough call between these two lenses but I have to give it to the RF 100-500mm. It’s AF performance is where it probably pulls ahead of the old lens and delivers more sharply focused images thus increasing it’s overall value relative to the old lens.
Canon RF 70-200mm f/2.8 L IS Vs. Canon EF 70-200mm f/2.8 L IS mk II/III
In 2023 the 70-200mm focal range is something of an anachronism. Despite this, Canon has decided to continue with the 70-200mm in the RF system. 70-200 designs are easy to get sharp and distortion free. Pretty much every company’s 70-200 is sharp and low distortion, whether it’s Tamron, Sigma, Sony, Nikon, or Canon, every one of these 70-200’s will deliver pro level results. Some will focus better than others, some might flare a little more, etc. But the bottom line is that they’ll be sharp and in focus most of the time.
So what did Canon do with the RF 70-200mm f/2.8 L IS to differentiate it from the field? They decided to make the smallest and lightest 70-200mm in the marketplace. The RF 70-200mm is a great lens optically, and it’s also about 30% lighter than most of the competing lenses while being every bit as sharp. The reduction in weight is very nice in a lens that is notorious for being a little on the heavy side. I have used several older 70-200’s and they’re all a bit of a drag because of the weight and size. The new one is definitely more stealthy which means you can feel less obtrusive when out in public with it. But even when doing professional work such as weddings, the fact that it doesn’t stand out as much can help the photographer sneak around and get shots without being so obvious.
Canon’s old EF 70-200’s were all well regarded but I think the RF is optically better and a lot more fun to use. While the new lens is 30% lighter, it feels a lot lighter even still because of the weight distribution. I would never take an old EF 70-200mm f/2.8 out on a nature hike, too much weight to be slinging around. But I’m happy to take the RF version because it’s just that easy to deal with.
The new RF 70-200mm f/2.8 L wins this matchup. There are a lot of good optics in the 70-200mm space so it’s almost splitting hairs to pick the best one optically. Canon realized this so they made a lens that is still razor sharp but also a lot more convenient to use. Convenience is one of those things that most photographers don’t ask for. But, it’s hard to go back to being inconvenienced when the performance is the same or even better. The only thing the old lens might be better for is taking pictures in the rain.
Canon RF 24-105mm f/4 L IS USM Vs. Canon EF 24-105mm f/4 L IS USM mk II
A common choice among many amateurs and semi-pro photographers, the Canon EF 24-105mm f/4 series has been going strong for nearly 20 years now. There are a lot of things to like about this type of lens starting with the convenient focal range. I had the Canon EF 24-105mm f/4 L IS USM mk II and it was a nice lens. I also have the RF 24-240mm f/4-6.3, and it’s actually f/5.6 at 105mm so I ended up selling the EF 24-105mm. I actually kind of regret doing that but it just didn’t make much sense to own both the 24-105mm f/4 and the RF 24-240. Especially since the 24-240 obviously gives a 10x zoom range. Overall I liked the EF 24-105mm mk II but it had some qualities that I never learned to love.
Most reviewers have concluded that the new RF 24-105 and the EF lens are pretty close to identical in sharpness at all focal lengths. The RF is better optically but it’s on the subtle side. The big difference is the native performance you get with having an RF lens on an RF mount camera. All things being equal including price, it comes down to that reality. A lot of the reasons to choose RF over EF lenses come down to RF lenses having better integration with the new cameras and their enhanced autofocus and stabilization capabilities. If you’re buying new the RF 24-105mm is a good choice over the older EF version. If you already have an EF 24-105mm and it works for you, you might be ok just keeping it. Optically the EF lens is still great for portraits, products, or landscapes in decent to good light. If you’re going for the face and eye tracking on moving subjects, consider the RF lens.
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