Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Lightroom Q&A => Topic started by: rabanito on March 05, 2020, 01:37:56 pm

Title: Chromatic Aberration Correction in LR
Post by: rabanito on March 05, 2020, 01:37:56 pm
I made a picture of a bird which shows a great contrast at the border.
It was made w/ a Nikon zoom (70-300) at 300mm 1/100 sec f/7.0 ISO 400 on an D810
I attached the whole picture and three examples (bird on the right).

The first example shows the blue fringe when no correction was applied
The second shows it after checking "Remove Chromatic Aberration" in LR
The third shows the picture fixed manually (also in LR)  - using the eyedropper  - to an amount of 7.
The blue line has dissappeared this time

My question is, since I applied the fix only to a specific point in the picture. How does it affect the rest of the image?
I don't notice any problem but I'm just curious of how this works.
Thanks
Title: Re: Chromatic Aberration Correction in LR
Post by: Kevin_Sink on March 20, 2020, 10:06:06 am
Iíve found removing CA from corners (often the most problematic region) can create terrible artifact in the center of the image, especially when correcting fringing around objects juxtaposed against a bright sky.  I havenít found a workaround in LR for this.  I use Lumemzia, a terrific contrast masking program for Photoshop, to select only the color of the fringing and then apply that mask to a Hue/ Saturation layer, then desaturate that color and sometimes increase luminance a tad.  It works very well and avoids the artifact LR or camera raw create.
Title: Re: Chromatic Aberration Correction in LR
Post by: rabanito on March 21, 2020, 05:58:27 am
Iíve found removing CA from corners (often the most problematic region) can create terrible artifact in the center of the image, especially when correcting fringing around objects juxtaposed against a bright sky.  I havenít found a workaround in LR for this.  I use Lumemzia, a terrific contrast masking program for Photoshop, to select only the color of the fringing and then apply that mask to a Hue/ Saturation layer, then desaturate that color and sometimes increase luminance a tad.  It works very well and avoids the artifact LR or camera raw create.

Thank you Kevin. I'll take a look to Lumenzia :-)
Title: Re: Chromatic Aberration Correction in LR
Post by: FabienP on March 22, 2020, 05:36:14 pm
Indeed, LR is dumb and treats the whole image with the same parameters, which might be OK for high quality primes but not for zooms. Other programmes like C1 and DxO Photolab have some functionality (sharpening, possbly others) that behaves differently according to the distance to the centre of the image.

This is an area where much could be improved in LR but this might require new lens profiles to be made. The current ones only deal with geometry distortion and vignetting. AFAIK everything else is done by analysing the image and thus unaware of the sensor and lens combo that is used.

Cheers,

Fabien
Title: Re: Chromatic Aberration Correction in LR
Post by: rabanito on March 23, 2020, 02:01:53 pm
I see.
Thank you Fabien. Very interesting
Title: Re: Chromatic Aberration Correction in LR
Post by: JRSmit on March 23, 2020, 04:01:31 pm
You have the "brush" in Lightroom, with which you can also remove these abberations in a controlled wat.