Noticeable Pincushion Distortion in PureRAW

Hi there. New user to PureRAW, migrating from Topaz DeNoise. The workflow on PureRAW is far superior so congrats on that :slight_smile:

However, i’ve noticed that some of the Lens Corrections apply a very noticeable ‘pincushion’ effect on images, so I did a few improvised test images to demonstrate. Am I doing something wrong or is this an error in the lens correction profiles?

This is using the following profile:

Here is an image processed through PureRAW with the Lens Corrections turn OFF - this then imports to Lightroom, and Lightroom does not apply its own corrections. As you can see, the lens naturally has a slight barrel distortion when uncorrected.

Here is the same, when Lens Corrections is turned on. As you can see, it corrects the barrel distortion but actually overcorrects and turns it into a pincushion distortion.

Finally, here is the RAW directly imported to Lightroom without using PureRAW, which means Lightroom will apply its own lens corrections using the embedded profiles in the RAW. While in other aspects (sharpness, noise, etc) it’s inferior to the PureRAW output, at least the lens distortion is corrected pretty much perfectly to my view.

The difference between the ‘perfect’ lens correction on the Lightroom lens-corrected RAW and the DXO lens-corrected RAW are noticeable easily in regular pictures - see the following two for example, they are noticeably geometrically different if you flick between the two.

Lightroom lens corrected:

PureRAW lens corrected:

Hi Daniel and welcome.

The distortion correction that is applied to RAW files by Pureraw is dependent upon the camera/lens module for any given camera/lens combination used for capturing the RAW file. It could be that the specific module used in your case needs to be reworked. It is also possible however that your copy of camera or lens deviates from the norm for that camera or lens and therefore is overcorrected by PR. Your best course of action is to create a support ticket at to see if anything can be done to correct your problem.

… and here’s the same photo as a direct-from-camera RAW in Lightroom. As you can see, it does not display the pincushioning effect that PureRAW adds.

I have noticed that in this specific case, in in-Lightroom adjustment to the Distortion geometry slider of about -5, largely corrects the issue - but I would need to do this manually for each processed image.

Hi Mark,

Thanks, I will lodge a support ticket.

It would appear the module needs reworking, as if it was a specific lens/camera issue then by logical deduction it should also show that distortion when using Lightroom’s own integrated camer profile. But it does not. Here’s another PureRAW tweaked photo of a test image on my screen…

Update - I figured out the issue and how to correct it, ironically not by using PureRAW but by using PhotoLab 5.

PL5 contains the same optics modules as PureRAW, however it has a relevant setting that PureRAW does not - focal distance. It appears the optics module impacts change depending on the focal distance.

The pincushion distortion on the PL 25mm f/1.4 pictured above occurs on the default setting - infinity focus.

However, I did not take this image at infinity focus - I took it focussed on a computer screen just under a metre in front of me. When you select the relevant distance - BAM! and the pincushion is gone!

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