Review of the Canon RF 100mm f/2.8L IS USM Macro Lens

Review of the Canon RF 100mm f/2.8L IS USM Macro Lens

It was only a matter of time before Canon would release a true macro lens for the RF mount. Instead of an RF version of the ever-so-popular EF 100mm macro lens, Canon had a little surprise up its sleeve. I got a chance to review this amazing lens.

When Canon Netherlands asked me if I was interested in reviewing the new RF 100mm f/2.8L IS USM macro lens I couldn’t say no. Previously I tried the RF 85mm f/2 IS STM macro, which is also a macro lens, but that only delivered a maximum reproduction ratio of 1:2. I find a macro lens is truly macro when a 1:1 reproduction ratio or more is reached. You can find my review of that RF 85mm f/2 macro lens by following this link.

So, Canon finally announced the RF 100mm f/2.8L IS USM macro lens. But instead of an RF copy of the EF version, this lens has a few surprises. First of all, it allows you to reach a magnification of 1.4 times. In other words, it goes beyond the 1:1 reproduction ratio which is quite nice. The second surprise is an extra control ring that allows you to change the Spherical Aberration of the image. More about that later. First of all, let’s have a closer look at this lens.

The Canon RF 100mm f/2.8L IS USM macro

How It Looks and Feels.

The RF 100mm f/2.8L IS USM macro is longer than its EF counterpart. Funny thing is, when the EF version is fitted with an EF EOS R mount adapter both have the same length. The finish of the RF lens is similar to other RF lenses, it doesn’t shine as much which is a good thing. It looks better, I think.

The RF 100mm macro next to the EF 100mm macro, fitted with the EF-R adapter.

It has all the control rings and switches you would expect from a macro lens. It has a good sized focus ring and the programmable control ring. The switches control the autofocus and image stabilization. Canon claims a 5 stop stabilization with normal use. When a 1:1 reproduction ratio is reached, this is reduced to only 2 stops. Of course, when paired with a camera that has an IBIS system, the total amount of image stabilization can reach up to 8 stops.

Unfortunately, the lens doesn’t have a distance scale behind a small window, similar to the EF 100mm macro lens. But when the RF 100mm f/2.8L IS USM macro is switched to manual focus, the camera will show a nice distance scale on the LCD screen complete with magnification. It is more precise compared to a window on the lens.

Details of the RF 100mm f/2.8L IS USM

Finally, the lens offers a ring that controls the Spherical Aberration, which is basically a way to control the bokeh when using a shallow depth of field. This ring can rotate up and down in a negative and positive direction. A small switch on the lens locks this ring in the neutral position, preventing movement.

The weight and size of the lens hold no surprises. It’s not too heavy and it balances reasonably well on a Canon EOS R5. When fitted on a tripod, the center of gravity is placed well in front of the mount. When a lower quality tripod head is used, I can imagine it will be difficult to hold it in position. There is a possibility to acquire a tripod collar, but it’s not included.

Using the RF 100mm f/2.8L IS USM for Macro

Although this lens can be perfect for portraits, just like any other 100mm lens, it is mainly for shooting small objects. With a minimum focus distance of 26 cm, you can reach a 1.4 times magnification, which is great. This way, the RF 100mm f/2.8L IS USM macro offers more possibilities for the macro photographer.

With this magnification, the image stabilization isn’t that effective anymore. I would recommend shooting from a tripod if you want such magnifications.

Shooting macro with an 1.4 times magnification. The result is visible in the gallery.

The SA Control Ring

Most striking about the RF 100mm f/2.8L IS USM macro lens is the SA control ring. This stands for Spherical Aberration which is a lens defect, so to speak. In almost every situation this defect is corrected as much as possible. This also applies to this macro lens, but Canon offers the ability to change this SA correction.

The RF 100mm f/2.8L IS USM macro is the first lens I know of that has a SA control ring.

The effect is best seen when shooting a light source out of focus. The appearance of the so-called bokeh balls changes when rotating the SA control ring. Rotate the ring towards the negative value and the bokeh balls become smaller. A rotation toward the positive value will make the bokeh rings larger.

Bokeh balls. These are reflections of sun light in a pond. Left is a negative SA, and at the right a positive SA. In the middle is the neutral setting.

There is a second effect that occurs when changing the Spherical Aberration. The subject will show a certain fuzziness. It’s as if a strong Orton effect is occurring, giving the image a soft appearance. It is something that not everyone will appreciate.

See how the sharpness is reduced with a negative SA (top) and a positive SA (bottom. The middle is the neutral setting.

There is also a slight change in the size of the subject you focused on. But fortunately, the autofocus system of the Canon EOS R5 has no problems with any soft focus effect that happens when the SA control ring is used. Even with that fuzziness, the camera can focus with precision.

Because of the strong effect the SA control ring has, Canon made a good choice to add a locking switch. It prevents accidental changes in the Spherical Aberration. Remember, when stopping the lens down, the effect of the Spherical Aberration will decrease. The effect works best when a shallow depth of field is used.

Heather in bloom. From left to right is a negative, neutral and positive SA setting.

My Conclusion

Although I haven’t tested the image quality of the RF 100mm f/2.8L IS USM macro in detail, I don't expect it to be disappointing. There is no way Canon can afford to release a lens that offers at least the same quality as its EF counterpart. Any vignetting will be corrected by the in-camera lens profiles, or in your favorite raw editor. The image stabilization offers a great number of stops, that become even more when compared with an IBIS system. The results I got were good.

Photographing butterflies in the Butterfly Safari in Gemert, the Netherlands.

The RF 100mm f/2.8L IS USM allows me to get up to 26 cm close, which is more than enough for my photography. Focusing is fast and without noise. Only an inaudible buzzing of the Image Stabilization can be heard when you put your ear to the lens. Even for action photography, the lens will perform very well, I’m sure.

The lens has weather sealing and the finish of a typical L-lens for the RF mount. But most striking is the SA control ring, something I haven’t seen on other lenses yet. It offers a change in bokeh, best visible when you add bokeh balls to your composition. I also think the SA control can be a great option for portraits. Unfortunately, the lens had to be returned to Canon Netherlands before I got a chance to shoot any portraits.

With a maximum of 8 stops image stabilization shooting without tripod is easy.

I can definitely recommend this lens to any macro photographer that uses an RF mount camera. It’s a very capable lens for portraits and macro. The increased magnification offers more possibilities, and the Spherical Aberration control allows you to add a special appearance to your images. It can be fun to experiment with.

What I Like

  • Size and weight is well balanced
  • Image stabilization up to 5 stops (increasing to 8 stops with IBIS)
  • Maximum magnification of 1.4 times
  • Fast and quiet autofocus system
  • Focus limiter with 3 settings
  • Spherical Aberration control ring for changing the bokeh
  • Locking switch for the SA control ring
  • Weather sealing

What I Think Could Be Improved.

  • Tripod collar is not included
  • Nothing else that I can think of

There is not much more to say about this macro lens itself. It’s the RF version of the EF macro lens and it was only a matter of time before it was released. But the 1.4 times magnification and the SA control ring are another thing.

What do you think? Do the increased magnification and SA control ring options increase the value of this lens? Or do you have another thought on these possibilities? Please let me know in the comment below.

Thank you Canon Netherlands for providing this lens. Too bad I had to send it back. And thanks to the Butterfly Safari in Gemert, the Netherlands for the hospitality.

If you want to learn all the tips and tricks of getting incredible macro shots, Fstoppers teamed up with Andres Moline to produce Mastering Macro Photography. If you purchase it now, or any of our other tutorials, you can save a 15% by using "ARTICLE" at checkout. 

Nando Harmsen's picture

Nando Harmsen is a Dutch photographer that is specialized in wedding and landscape photography. With his roots in the analog photo age he gained an extensive knowledge about photography techniques and equipment, and shares this through his personal blog and many workshops.

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Thank you for your review. I've read and seen a few but none of them touched the issue of chromatic abberation which is a bit of a problem with EF100. Have you noticed how the RF copes with it?

There is some chromatic aberration. If it's better controled or not, that's something I can't say. Using the sferical aberration control ring towards the negative side will increase the chromatic aberration also.

I love the lens and have been having fun with it. Don't understand why the collar isn't available. And I don't understand a lot of what you are talking about. Do a video and explain how to use the lens in a way that will get the most out of it. I have an r and an r6.

Personally I prefer written text.

Great and very informative review. I’m passing on this lens though. At least for now. The SA feature is pointless for me. I never liked the soft focus. A variable DS option would be much more desirable. I also wish they would make this lens compatible with teleconverters (like the Sigma 180/2.8 APO).
Great images BTW. With your skills you would make them with any lens :)

That is also the thing I was wondering about: the lack of compatibility when it comes to tele converters.

I wrote to Santa to bring this lens to me, so I can't wait Christmas eve

I think there IS a precedent for this lens - the Nikon 135mm and 105mm f/2 DC (defocus control) lenses released years ago. The "defocus" control introduced undercorrected SA selectively either behind or in front of the plane of focus depending which way it was turned (presumably overcorrecting it on the opposite side). Some was introduced AT the plane of focus in either case, giving a soft-focus effect which could be varied as the "defocus" control was variable. Chromatic aberration was well controlled, no obvious fringeing being introduced in the process.

It was largely about bokeh - increasing (undercorrecting) SA behind the plane of focus was intended to improve the quality of bokeh behind e.g. a portrait subject, somewhat as if a much longer or wider-aperture lens had been used. However, the effect did not require shooting wide open, increasing the flexibility - and potential for confusion!

With this control zeroed, the 135mm lens was VERY sharp. Still is. Both were regarded as good sharp lenses.

Canon had an EF 135mm f/2.8 lens with a soft-focus control as well. I had a Tamron 70-150mm soft-focus zoom which introduced SA at the focal plane. Unfortunately, the soft-focus effect was ruined by gross over-correction behind the focal plane, giving hideous bokeh which would put a mirror lens to shame! I dumped mine, unloved.

Thank you Chris Jablonski. That is very informative. Now you mention it, I remember the EF 135mm f/2.8 with softfocus.

Cool gallery.

It's nice to know that the AF responds in spite of SA. When focusing for example the Meyer Görlitz Trioplan 100/2.8 those SA result in a kind of focus tunnel, where the edge detection of the focus aid goes mad and you can't rely on it anymore. One has to switch it off and focus by viewer magnification to find the middle between near sharp glowing edges to find the best focus. This glow effect is also here to be seen, but without those focusing trouble it's a nice addition for portrait photographers, I guess, who seek an extra effect.

I think it's a good thing Canon managed to keep the AF available with the SA changes. Is focus peaking possible whith that Meyer Görlilz Trioplan? That could help getting a good focus.

Well, no, as focus peaking highlights way too much that just isn't in focus. The magnification helps, so this focusing aid works well. It takes more time.

If it takes more time, you can enjoy photographing with the lens even longer ;)

I’ve only had mine for a few days but the 1.4x magnification, sharpness, lack of CA, and decent image stabilization handheld is fantastic. My only complaint is that it is super sharp wide open meaning diffraction kicks in a bit early and when using this lens at minimum focus distance you *need* f/11 (or focus stacking) to get any amount of depth of field, and diffraction starts to become prevalent at f/8 in my experience so far. Haven’t explored the SA control yet. Great lens, a bit pricey though. Would’ve preferred 1.4x with no SA control for less money. I’m sure there’s a 200 f/4 macro on the way though.

The loss of sharpness @ F/8 could be attributed to the focus shift as TDP found out: (search for "focus shift"). It's too early for diffraction to become really noticeable.

"It's too early for diffraction to become really noticeable." Exactly, diffraction comes from the physical size of the aperture.

It is odd to me that this is the only review that I've seen to even mention this issue. They document it pretty well, but seemingly no one else has encountered the problem, or realized that they did? Seems like someone else would have noticed...

Well, he’s a professional optics tester. He also got an official response from Canon:

“The focus shift is not sample dependent and is not related to the SA control ring. As focus shift is characteristic of this lens, no production changes to the lens or lens/camera firmware updates are anticipated. Correction, when necessary, is accomplished by focusing slightly in front of the subject.”

IMO this could be fixed via a firmware update by either applying an AF correction based on a distance / aperture lookup table or just letting the camera to focus stopped down.

Yeah I saw that, that seems like an annoying thing to just have to accept...

Diffraction is a bitch. Using a lower resolution sensor could help. I wrote an article about diffraction and how it's influenced by focal length, magnification, and sensor resolution. Just like Tammie Lam is mentioning, the Digital Picture dives much deeper into this specific optical effect.

What is the intended application for the SA ring for macro? Maybe for a portrait, you could achieve some sort of interesting effect, but for a macro application, why would you want to introduce, well, "fuzziness"?

it's a 100 mm 2.8 lens - it should be fully capable of producing excellent portrait images

yet - no mention?

No mention because I didn't use it for that purpose. If I use a macro lens, I use it for macro. If I want to shoot portraits, I use another lens for that.
I decided to see how it's performing for macro only

Hi, thanks for the article and the beautiful pictures. I have a kind of basic question: how do you turn on this magnification? I'm using a canon r6

Just like every macro lens, the magnification is achieved by a close focal distance. The closer you get, the bigger the magnification will be. So, the closest focus distance will give you the biggest magnification.