Pages: [1]   Go Down

Author Topic: Latest greatest Chromatic Aberration fixers?  (Read 1595 times)

earlybird

  • Full Member
  • ***
  • Offline Offline
  • Posts: 195
Latest greatest Chromatic Aberration fixers?
« on: January 10, 2018, 05:47:26 PM »

Hi,
 I have a Canon EF 100-400mm f/4.5-5.6L IS II USM lens and have found that despite the favorable reviews the chromatic aberration with this lens is undesirable.

 I have only tried Camera RAW lens correction, and Photoshop's Lens Correction filter,  and I have not found the CA correction process to works as effectively as I might hope.

 On one photo I found the color correction aspect of the filter to work ok but saw that the entire photo was distorted with the effect of shrinking the entire picture so that a new frame was created a few pixels inwards from the original dimensions.

 Sometimes, I have found that careful use of the basic Hue/Saturation process gives me more control than the Lens Correction features.

 I wonder if there is something that works especially well. Is there something else to try?

 Thank you.
 
Logged

trshaner

  • Newbie
  • *
  • Offline Offline
  • Posts: 33
Re: Latest greatest Chromatic Aberration fixers?
« Reply #1 on: January 10, 2018, 06:22:32 PM »

This lens has very low CA, which should be nearly fully corrected by checking 'Remove Chromatic Aberrations in the ACR or LR Lens Corrections panel. Can you upload an example raw file that has significant CA for examination?
Logged

Hening Bettermann

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 910
    • landshape.net
Re: Latest greatest Chromatic Aberration fixers?
« Reply #2 on: January 10, 2018, 06:34:52 PM »

I found the automatic CA correction of Raw Therapee to be very good, better than my manual best effort in Iridient. And RT has a very good (manual) correction for longitudinal CA as well. 

BartvanderWolf

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 7195
Re: Latest greatest Chromatic Aberration fixers?
« Reply #3 on: January 10, 2018, 06:58:46 PM »

I wonder if there is something that works especially well. Is there something else to try?

Hi,

Hard to say without an example, but Capture One Pro has a pretty decent CA correction with Raw conversions. Also, Affinity Photo has an effective CA correction, which can be applied as a postprocessing step. But that's specifically for Lateral CA which I assume is what you are referring to, not Longitudinal CA.

BTW, have you tried Canon's Digital Photo Pro converter?

Cheers,
Bart
Logged
== If you do what you did, you'll get what you got. ==

earlybird

  • Full Member
  • ***
  • Offline Offline
  • Posts: 195
Re: Latest greatest Chromatic Aberration fixers?
« Reply #4 on: January 11, 2018, 07:49:03 AM »

Hi,
 Thank you to everyone for the suggestions.

 The examples I am working with exhibit Lateral CA in the corners of scenes of richly colored desert landscapes draped in fresh powdery snowfall. Most of the frames were composed so that a hyperfocal focus point would permit sharp focus from foreground through to distance. Some of the images were focused stacked when a hyperfocal value was inadequate for sharp rendering of the entire scene.

 The images are meant to invite scrutiny of the fine details, and while the CA is only discernible at coarser pixel density than the images will be printed at, I hope to minimize any effect of color cast even if the tell tale line of magenta and or green is not readily identifiable in the final print output.

 I look forward to trying some of the suggestions mentioned here.

 Thank you.
Logged

Peterretep2

  • Newbie
  • *
  • Offline Offline
  • Posts: 10
    • Mountain Photographics
Re: Latest greatest Chromatic Aberration fixers?
« Reply #5 on: January 11, 2018, 08:24:18 AM »

I still  have to deal with CA if I'm not using a couple of my lenses that barely exhibit  that problem. I do it manually by creating a dupe layer and applying a blur and reducing saturation to it, then blending it by color. I apply mask all and then use my brush to paint the layer where it's needed. Sometimes I select the color of the CA to speed up the process when applicable.
Logged
Photography by Peter Montanti, www.mountainphotographics.com

trshaner

  • Newbie
  • *
  • Offline Offline
  • Posts: 33
Re: Latest greatest Chromatic Aberration fixers?
« Reply #6 on: January 11, 2018, 09:31:30 AM »

There should be no need to resort to creating layers in PS, etc. to remove CA in most any image file. LR/ACR 'Remove Chromatic Aberrations' in the Lens Corrections> Profile panel should be checked as your Develop Default Setting. I have yet to see any image file that negatively affected by doing so! Any remaining CA in the image is most likely of the Axial (longitudinal) type, which can be removed using the 'Defringe' tool in the Lens Corrections> Manual panel. I've created Develop presets with just the Defringe settings for lenses that exhibit Axial CA. For Zoom lenses you may need to create two or three presets based at behavior across the focal length range. It's not as hard as it sounds.

Here's an example using a Canon EF 8-15mm f/4L Fisheye USM lens, which exhibits very noticeable Axial CA. I had to create two presets with the only difference being the 'Amount setting, which is '4' for 13-15mm and '2' for 8-12mm focal length. Why? Using too high an amount setting can cause areas in the image that are near the same color as the Defringe sample to become desaturated. These are very low Defringe Amount settings, but work very well as you can see in the below example. Use the lowest possible Amount setting that removes most of the Axial CA. Here's more info on the LR/ACR Defringe tool:

http://blogs.adobe.com/lightroomjournal/2012/04/new-color-fringe-correction-controls.html
Logged

kers

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 1851
    • Pieter Kers
Re: Latest greatest Chromatic Aberration fixers?
« Reply #7 on: January 11, 2018, 09:53:58 AM »

The images are meant to invite scrutiny of the fine details, and while the CA is only discernible at coarser pixel density than the images will be printed at, I hope to minimize any effect of color cast even if the tell tale line of magenta and or green is not readily identifiable in the final print output.

Maybe you ask to much of a zoom lens in this respect.
Zoomlenses i am familiar with always corner problems, even fixed focal lenses.
yes, a perfect image you may expect from the new Nikon 180-400, but that costs...
Logged
Pieter Kers
www.beeld.nu

earlybird

  • Full Member
  • ***
  • Offline Offline
  • Posts: 195
Re: Latest greatest Chromatic Aberration fixers?
« Reply #8 on: January 11, 2018, 10:07:50 AM »

Mea Culpa:

I have written that the images exhibit some lateral CA but I will also add that the color fringes seem to be magenta ( or pinkish red ) and green ( tending toward aqua ).

Logged

trshaner

  • Newbie
  • *
  • Offline Offline
  • Posts: 33
Re: Latest greatest Chromatic Aberration fixers?
« Reply #9 on: January 11, 2018, 10:13:38 AM »

"Maybe you ask to much of a zoom lens in this respect.
Zoomlenses i am familiar with always corner problems, even fixed focal lenses.
yes, a perfect image you may expect from the new Nikon 180-400, but that costs..."


But that's the whole purpose of the LR/ACR Lens Profile tools! You can take a mediocre lens and make it perform like a much more expensive lens. This is true for Distortion, Vignetting, Chromatic Aberration, and in many cases image sharpness fall-off. The latter using a Radial Filter that applies graduated Sharpening to the lower resolution edge and corner areas. You then create Develop presets to apply these corrections on Import. EZ PZ!
Logged

kirkt

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 474
Re: Latest greatest Chromatic Aberration fixers?
« Reply #10 on: January 11, 2018, 10:30:23 AM »

Download a trial of DxO PhotoLab - after launching the software and navigating to the offending image, select it and, when prompted, download the appropriate correction module for your lens+camera combination.  The aberration correction should be applied by default based on the correction module.  If not, enable the correction.

If you would like to see what DxO (or any of the other suggested applications) can do, upload a raw file to a file sharing service and post the link here.  I would be glad to run it though all of the raw converters I use that enable these types of corrections to be made and post a 100% crop of each result.

kirk
Logged

sankos

  • Newbie
  • *
  • Offline Offline
  • Posts: 35
  • Why matters
Re: Latest greatest Chromatic Aberration fixers?
« Reply #11 on: January 13, 2018, 03:50:30 PM »

Download a trial of DxO PhotoLab - after launching the software and navigating to the offending image, select it and, when prompted, download the appropriate correction module for your lens+camera combination.  The aberration correction should be applied by default based on the correction module.  If not, enable the correction.

Watch out for the DxO Moire and Purple Fringing corrections. Also, don't accept the CA removal wrt the size parameter (I set mine at 2). It's easy to observe the globally destructive nature of Moire and PF removal on the DPR or IR studio test shots, where small, colourful details (red, blue) get muddled. In portraiture that might mean discoloured eyes or lips -- not good.
Logged
Pages: [1]   Go Up