Canon RF 24-240

I’ve just bought myself a Canon EOS R and the RF 24-240 lens as an early Christmas present.

Having looked at the various reviews, it is clear that the lens/camera does some clever internal process to stop vignetting with RAW files at the short end.

Anyway, with my first photos, they looked ok when importing to Canon digital professional 4, but when I open in Photolab 4, the lens correction is not working (only at the short end and with RAW files).

Naturally, as soon as I opened the photo in PL4, it offered to download the correct camera/lens profile (both JPEG and RAW profiles are available for this camera/lens combination) but the RAW image does not get corrected - see below (I’ve saved as a JPEG to keep the file size down):

Now the interesting thing is that I then opened the file in PL3 and again it downloaded the camera/lens module, but this time, PL3 does the lens correction as I would expect with no vignetting.

I then tried removing and reinstalling the lens module in PL4 but it made no difference.

Accordingly I would suggest there is a problem with the lens module (or the manner in which PL4 uses the module).

Can anyone help?

Thank you
Malcolm Clark

That vignetting is not vignetting. There is NO information in the corners! Vignetting is darkening, not complete removal of photons reaching the sensor. I would turn in the lens and ask for a refund. Really.

There are other possible explanations. A lens hood that isn’t securely attached. Or this is how the RAW image looks without optical corrections and without the default crop.

Are your Crop settings the same between PhotoLab 3 and PhotoLab 4? What about lens correction, distortion, and perspective correction settings?

Hi Perfode
I accept that this isn’t vignetting in the normally used sense of the word but if you do a search on the lens, this is how others describe it. So I thought I would use the term since it describes the ‘look’.

The problem isn’t unique to my lens - I accept it may not be great from a pure optics point of view, but clearly this is what Canon do to accommodate the large range in focal length covered by the lens.

No it’s not a lens hood or anything like that. I opened the same file without any correction in PL3 & PL4 and PL3 fixes it and not PL4. Indeed when I opened the file in PL3 it appeared the same as my photo above but then once the camera/lens profile was installed the ‘vignetting’ disappeared.

I think the ‘issue’ must be known to PLab - this is the only lens I have where PL has both a RAW and a JPEG profile. It’s just that the RAW profile works in PL3 but not PL4.

I’m open to that possibillity, but have to be skeptical too. What do you mean by “without any correction in PL3 & PL4?” If there’s no correction, then how can PL3 fix the image?

Hi @Egregius
What I’m saying is that if I take the (totally unprocessed) RAW file, it does not correct the ‘vignetting’ in PL4, despite having the camera/lens RAW profile installed.

However PL3 with the same image and the same camera/lens profile installed does correct it - see below (again a JPEG export):

This appears to be an issue that the DXO staff will have to weigh in on. Hopefully it can be easily resolved, but there is always the possibility that this is a bug.


This picture i cropped compared to the picture with “vignetting”. So, the lens is therefore not a 24mm lens if you can not use it as such. Return it.

The lens is bugged. No RAW converter can guess what is in an area (the corners) that has NO information.


I understand your concern and I accept that there may be a fundamental ‘lack of purity’ in the way in which Canon designed the lens. Nevertheless, I do not believe my particular lens is ‘bugged’ as you put it - it would appear to be something that is common to all RF 24-240s.

I agree that the RAW converter cannot guess what is in the corners. But Canon DPP; PL3 and the image on the camera screen show a correct, adjusted (and obviously slightly cropped) image.

If PL3 can do the proper adjustment and PL4 cannot, then I cannot understand why you deduce it’s an issue with the lens rather than an issue with PL4.

Will DXO staff automatically respond to this thread, or do I need to raise it as a support issue?

Thank you

You can raise a support issue but, for now, I’ll ping @sgospodarenko to see if she can do anything.

In the meantime, do you want to share one of these files here so we can play?

Thank you. I just tried to upload the RAW file but I cannot because the site won’t allow me to upload a CR3. Unless there’s another easy way?

CR2 is allowed. Maybe it is too large? Try zipping it?

Yes, that is the solution. DxO allows to show more of a picture after distortion correction than most other RAW editors. I bet that crop settings are different in this installation between PL3 and PL4, perhaps a difference in the default preset.

I put both in layers in Affinity and they are nearly identical but the crop:

So no defect, just DxO revealing that this lens is near its limits.

Also I agree that this is not the usual vignetting which can be corrected. It is the limit of the image that the lens projects onto the sensor.

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Thank you - here’s the zip of the CR3 file: (31.7 MB)

Yes, I agree with what you say. But really all I’m hoping for is that PL4 would adjust the image in the same way that PL3 does. Yes, I could manually crop each photo but that seems a bit of a step backward when clearly PL is capable of doing it.

OK, here’s how it goes.

Download file and open in PL4 - corners are cut off

Download the DxO module

Apply the four module specific adjustments that are necessary.

  1. Vignetting
  2. Lens Sharpness
  3. Chromatic Aberration
  4. Distortion


The missing piece of the jigsaw for PL4 is to use the “2 - DxO Optical Corrections only” preset.

This is new and maybe you are currently using the No Corrections preset to all new files?

News just in!!!

You need to make sure that the Distortion palette has the Keep aspect ratio checked. Something that is not done in the DxO’s Optical Corrections only preset, so I added it to my own custom preset, copied from DxO’s Optical Corrections and made that the default.

Here’s the preset I made

Optical Corrections only.preset (9,1 Ko)

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Thank you for the effort you are putting into this. And I must admit that I thought you had ‘got it’. However all my settings are as per your list. I do wonder if it’s just something specific to my camera/lens module or the way it is being installed in PL4.

To try and test this, I just removed the lens module, restarted PL4, went back to my image and then reinstalled the module - with the result that the ‘vignetting’ decreased quite a bit compared to when the module was not installed - but not as much as the image you posted. Again, I checked that all my settings as specified by you are the same.


Exactly. So, return it. I can however not see why PL4 has to crop this photo for you instead of you doing it yourself.

Are you sure that the “Keep aspect ratio” box is checked?

All you need to do is import my preset and apply it. Then you can make it the default for opening all RAW files.

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Thank you so much for your help. You are correct - it was the ‘keep aspect ratio’ box on the distortion tab that needs ticking.

Again, thank you for your comments, but I’m not going to return the lens. As I’ve said before, the way in which Canon achieve their results may offend you (as they do me) from a purist point of view, However, I accept that there have to be compromises in producing a lens with the large focal length range of 24-240 and at the same time keeping hat lens down to a reasonable weight (and price point).

I managed to break my back earlier on in the year and cannot (currently at least) walk around with a rucksack and half a dozen heavy lenses as I used to. My new camera and lens was purchased with the specific aim of having a single camera/lens that I can walk around with all day and still produce photos that are acceptable (at least to me).

Thank you everyone for your help.

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