We Review the Canon RF 24mm f/1.8 Macro IS STM Lens

We Review the Canon RF 24mm f/1.8 Macro IS STM Lens

Canon has released a series of nice primes that are reasonably priced and in a friendly size and weight. Most of these lenses also have 1:2 macro abilities. The latest one is the RF 24mm f/1.8 Macro IS STM. Let’s find out if it's just as great as its siblings.

I’ve been using the cheaper RF primes on occasion. I wrote about my experience with the RF 16mm, RF 35mm Macro, and the RF 85mm Macro during my scouting trip in France. I also used the RF 50mm f/1.8 for a few shoots and made a complete review of the RF 85mm Macro here on Fstoppers.

The three amazing lenses I took with me to France. Read all about it in my article on Fstoppers.

The 50mm plastic fantastic version for the RF system. Not perfect, but cheap and fun to use.

Now, Canon Netherlands provided me with the latest sibling in the series of relatively cheap RF primes. It’s the RF 24mm f/1.8 Macro IS STM, which is a great addition when it comes to focal length. Especially for landscape photography, it’s the sweet spot. It doesn’t show the typical wide angle distortions, and a polarization filter can be used without an obvious uneven polarization effect. It’s also great for full-body portraits and wedding photos.

The newest addition to the affordable series of RF lenses. yhe RF 24mm f/1.8 Macro IS STM.

How It Looks

As expected, the RF 24mm looks similar to all the other lenses in this series. It has the same build quality and the same finish. Also, size and weight are comparable, except for maybe the RF 85mm. The lens has a dedicated focus ring and the programmable Control Ring. There are two switches which allow the user to turn off the autofocus or the stabilizer. These are great additions, since they prevent the need to dive into the menu system to turn them off.

Very useful switches on the lens for focus and stabilization. No need to dive into the menu.

Just like the other lenses in this series, it will extend while focusing. The lens becomes 1.3 centimeters longer. Although it’s not that much, looking at the overall length of 7.2 centimeters, it’s substantial. If you remove the lens while the camera is still turned on, the lens tube will stay in its position. It will only retract if the camera is powered down, unless you have deactivated the retraction of the lens in the menu, that is.

It's just 1.3 centimeters, but because of the small size of the lens, it's enough to make it more than noticeable.

The Image Quality

With the RF 24mm macro lens, you have to rely heavily on the in-camera lens correction. With the maximum aperture opening of f/1.8, the lens performs quite well in the middle. The sharpness becomes less impressive towards the edges. Vignetting is strong at that aperture also, up to four stops.

This is how the vignetting is with the RF 24mm f/1.8. In-camera lens corrections are disabled.

Fortunately, the quality at the edges improves significantly when stopping down to f/4 or f/5.6. The vignetting will also decrease until it’s not that noticeable anymore. If the in-camera lens corrections are activated, the vignetting will be corrected completely, even at f/1.8. This will require an exposure correction at those corners of almost four stops, which might result in a slight increase in noise levels in those areas of the image.

Besides the sharpness and vignetting, the lens shows a strong barrel distortion. This is corrected also with the in-camera lens correction. It requires some stretching of the edges of the image, which may result in a decrease in image quality again. Notice how the corrected image has some quality loss, but this becomes apparent only when the image is viewed without lens correction in post-processing software.

The strong barrel distortion is corrected with the in-camera lens correction. It will have an effect on the amount you will see in the frame.

The Image Quality in Real Life

Looking at image quality in great detail will reveal a lot of imperfections that will be almost invisible in real-life situations. That’s why I prefer to take the lens out into the field to see how the results are with normal use.

I have made some comparison shots at f/1.8 and f/4, with and without the in-camera lens correction activated. Without the lens correction, the vignetting is prominent at f/1.8, but at f/4, almost unnoticeable. With the lens correction activated, both images show no signs of vignetting anymore.

The vignetting and sharpness in a real-life situation. The lens correction makes it quite a useful lens.

The funny thing is, on a lot of occasions, we tend to add vignetting in post-processing to capture a viewer's attention in the middle. Of course, this is more controllable than the natural vignetting of a lens. But it shows vignetting isn't always a bad thing.

This is how the lens performs in everyday use. The vignetting is corrected in camera, but added again to an extent in post. 

Also, for portraits, the corners are often less important because the subject is more center frame. If a shallow depth of field is used, the lack of image sharpness is not that important anymore. If you need a larger depth of field, you will stop the lens down to f/5.6 or f/8, in which case, the sharpness is significantly better.

At f/4, the lens performs well, but with in-camera lens correction activated. 

If the RF 24mm is used on an APS-C camera like the Canon EOS R7 or EOS R10, the field of view will be reduced to a 35mm full frame equivalent. In that case, you lose the outer part of the image circle, which is the weakest part of the lens.

Using Macro

The minimum focal distance of 14 centimeters allows a 1:2 magnification. This makes the RF 24mm a macro lens, which can be considered quite unique for this focal length. It allows you to shoot macro with a wide field of view, capturing small things together with their surroundings.

Using macro with the RF 24mm works well.

The shallow depth of field in combination with the macro capabilities work well. There is nothing to worry about concerning lack of sharpness at the corners this way.

Add the f/1.8 to the equation, and it will allow nice macro landscape photography with a shallow depth of field. You will have decreased sharpness at the edges, but this will be lost in the unsharp background. I think the macro function is a great addition that makes the RF 24mm Macro a lot of fun to use.

My Conclusion

Looking at the RF 24mm f/1.8 macro IS STM from a clinical perspective, it doesn’t have stellar performance. Most of its lens defects are corrected when the in-camera lens corrections are activated, but that might reduce the image quality in the far corners of the frame. Especially at the f/1.8 aperture, the sharpness in those corners isn’t that great.

Since the sharpness isn’t something that is easily corrected, I don’t think this lens is usable for images that need edge-to-edge sharpness with a wide aperture, like photographing a night sky. But for normal use, the lack of sharpness will be less of an issue. Most images with a shallow depth of field only need sharpness at the point of focus, which is seldom at the edge.

Our dog, Bruc, as a model. Shot with the RF 24mm and an aperture of f/7.1.

Stopping down makes the image quality much better. This makes the RF 24mm a great lens for both full-body portraits and landscape photography. Add the macro capabilities to the equation, and it's a great lens with lots of possibilities. It may not be perfect, but that can’t be expected from a relatively cheap lens. The in-camera lens corrections will solve a lot of the issues, fortunately, resulting in a nice, clean image in the end.

For video, the RF 24mm will perform nicely. The 16:9 aspect ratio will hide the corners and the lack of sharpness when used at f/1.8. The STM focus system is quiet enough for video.

The STM focus system works silently and smoothly. It’s accurate and fast. The lens also has image stabilization built in that rates up to five stops. This is quite unique for a lens with such a short focal length, but very helpful. There is no focus breathing, which is great news for filmmakers.

There is only one other downside to this lens. It costs $599. Looking at the quality and at the prices asked for the other lenses in this series, I find it to be a bit too expensive. On the other side, since this focal length is so versatile, the RF 24mm might be used quite a lot. In that case, it can justify the price, maybe.

I find the 24mm focal length ideal for most wide angle landscape photography. The size and weight makes it no problem to take the camera with you.

What I Like

  • Small and lightweight
  • Image stabilization up to five stops
  • Silent and fast STM focus system
  • Switches for the AF and IS on the lens
  • No focus breathing
  • Excellent sharpness in the image center
  • Macro capability up to 1:2 magnification

What I Don’t Like

  • Lens barrel extends during focusing
  • Strong vignetting at f/1.8 (becomes better from f/4 onward)
  • Lack of sharpness at the corners at f/1.8 (becomes better from f/5.6 onward)
  • Strong chromatic aberration at f/1.8 (becomes better from f/4 onward)
  • No dust- or weather-resistance
  • Strong barrel distortion (fixed with in-camera lens corrections)
  • Not suitable for night sky photography
  • Although reasonably cheap, still a bit too expensive

Is it a perfect lens? No. But its image defects won't be noticeable on most occasions due to the way it's used. I can recommend the lens if you don't mind the price. It may be reasonable, but not that cheap.

Despite it’s downsides, I think the RF 24mm f/1.8 Macro IS STM is a great lens nevertheless. Most of the downsides won’t be noticeable or even visible during real-life use. I can recommend this lens if you can live with the price tag.

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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