Distortion control and when it's applied...

[crimbfighter]

Kind of a dumb question, but I found myself over thinking this one.. I recently updated the firmware on my D5000, which updated the distortion control data for various lenses. It got me thinking.. When does the camera apply the distortion control? Is it only when it process out the JPEG, like all other settings? Or, does it apply it to the RAW image as it's capturing it? I know it makes sense to apply it at the same time it applies everything else, but then I doubted myself, thinking, well maybe distortion control is a different animal, and it's applied separately..

Secondly, if it only applies it to the JPEG, (which I would tend to think is the case) does it save the distortion control data with the other EXIF data so whatever program you use for post can read and apply it as the default distortion control for that lens/focal length combination on that image?

 

[KmH]

It's my understanding that data is only used by editing software, like Adobe Camera Raw (ACR - Camera Raw/Lightoom).

 

[crimbfighter]

Hmmm, interesting. I hadn't even though of that angle. Makes sense, though. It's probably a lot of processing for the camera to try to accomplish. Thanks for the reply.

 

[SoCalTiger]

My understanding is that the camera directly applies lens correction data if you are saving as JPEG but has no impact on raw formats and that the firmware was specific to the in-camera processing. I didn't think that the firmware per se impacted what ACR saw or what was saved in the raw file itself?

I guess one way to confirm it would be to NOT download the lens distortion data to your camera and see if ACR can still process the appropriate lens correction.

 

[SoCalTiger]

I just did a quick check in ACR. ACR does have it's own repository of lens correction data which is independent of camera firmware. For instance, I can choose lens correction data for a camera which I don't even own and it will work.

So, to answer the OP's question - the lens correction data in the firmware would only apply when saving images to JPEG. The raw image is unaffected and lens correction would be applied later using software.

 

[Skaperen]

It certainly should not be applied at all ... to the RAW files. For best results, shoot RAW and post process them. The distortion data would be added in and/or known by the software. And there are post processing tools to change the distortion, anyway, especially the common and well known barrel and pincushion. Some can also change angle of view, such as correcting an architecture shot angled up to look like your did a vertical shift. Fisheye to rectilinear wide angle is also possible. So distortion control is already well beyond just correcting design tradeoffs in your lens.