Chromatic Aberration Correction?

Discussions, questions, comments and suggestions regarding Capture One PRO, Capture One PRO(For Sony), Capture One DB and Capture One Express(For Sony) 11.x for Mac

Chromatic Aberration Correction?

Postby Mark BCN » Sun Jul 29, 2018 1:29 pm

I have a set macro images (B&W film scans) shot in hires mode using an Olympus E-M1 mark II and imported as 80MP RAW files to CO11.2. The images were shot with the Olympus 60mm f2.8 macro lens.

By default CA correction is off, and the images look pretty good with just a hint of colour fringing. But if I just tick the CA correction box, the result is *much* worse unless I also use the "analyse" image option - which cleans things up completely.

Is this really normal behaviour?
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Re: Chromatic Aberration Correction?

Postby Ian3 » Sun Jul 29, 2018 2:09 pm

To check CA correction you need to look at the image at 100%. It's one of the few adjustments that the preview doesn't really show the result of adequately.

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Re: Chromatic Aberration Correction?

Postby SFA » Sun Jul 29, 2018 3:15 pm

Mark BCN wrote:I have a set macro images (B&W film scans) shot in hires mode using an Olympus E-M1 mark II and imported as 80MP RAW files to CO11.2. The images were shot with the Olympus 60mm f2.8 macro lens.

By default CA correction is off, and the images look pretty good with just a hint of colour fringing. But if I just tick the CA correction box, the result is *much* worse unless I also use the "analyse" image option - which cleans things up completely.

Is this really normal behaviour?


You would probably need to ask Phase via a Support Case but I would guess that auto adjustment assessment is likely based on expectations of working with typical digital images on normal subject matter with the Analyse option available for things that don't work out for some reason.

If my reading of the related Help information is correct the lens tool will, by default, use any built in CA correction provided by the lens. If the lens does not provide any correction data or if it does no provide a pleasing result one can run the Analyse option and C1 will create its own adjustment and it seems in the case you have described running the C1 Analyse function is your best option.

It's probably worth considering what happens should you use one image to set up adjustments to be applied to a larger set of images. If you copy the lens corrections between images I think you will find that the CA correction, based on the original image edited, will be copied too unless you exclude it using the Clip Board functionality. This may or may not work for you in the situation you describe.

However, according to the Help, if you select multiple images and have C1 set to "Edit all selected variants", each image will be analysed individually in a batch run.

In summary - yes, I suspect that what you have discovered is probably expected.

HTH.


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Re: Chromatic Aberration Correction?

Postby Mark BCN » Sun Jul 29, 2018 8:13 pm

Yes, this was looking at tight crops (400%).

I wonder if the CA correction data is coming from the lens itself, as part of the reported corrections to apply. If the lens reported data is incorrect it would explain what I see and also why I have not noticed this with other lenses in the past.

Thanks for the tip of the batch processing. Fortunately it is very easy to fix the images!
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