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Chromatic Aberation bug?

Raymond Hearn
Correcting CA in previous versions up to v7 was no problem if there was no profile for your lens / camera combination. You simply selected Chromatic Aberration / 'analyse' and got good (sometimes slow) correction.

In version 8.0.1pro since my lens is not listed, I selected 'generic' profile and clicked on 'analyse' as before. However after the analysis progress bar is done nothing is changed i.e. no correction happens. The only workaround is to find another profile in the lens list, choose that, and see if the correction is suitable. In my case my lens Canon 300 2.8L is not there - I can get reasonable correction using 100-400L profile. (in case smoeone says i have a faulty lens, the CA is from the 2X extender).

So is this a bug in the CA correction menus?
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Comments

11 comments

Date Votes
  • Robert Whetton
    300 f/4 not a better fit?
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  • SFA
    I thought I had a perfect sample of shots to test this but it turned out they were mostly Purple Fringing and the CA stuff was mostly green/cream edges (Cricket shots taken with an old Canon FD 600mm lens) so the green was really part of the the green background and went untouched - which seemed sensible in the circumstances.

    After about an hour of digging around I came up with some frames from my Canon S90 (which as it is is unsupported although other models of that range would do). Converting the original V7 edits to V8 I could see changes to the CA values (leaves against a bright sky) changing switching CA on and off and this happened whether using Generic or Canon S100/110 values. In this case it was a lot easier to see at 400% as the aberration was quite slight.

    Purple Fringe correction is more evident on the Cricket shots and C1 does a terrific job with that.

    I'm using 8.0.1 on Win 7 Pro.

    HTH.


    Grant
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  • Raymond Hearn
    Correction to differing degrees of success works with almost any selected profile, but my issue is that no correction at all is applied with 'generic' choice. In ver 7 and before, when selecting the 'analyse' choice the image would be analysed and correction was calculated and applied successfully. This was not instant, some images depending on content took several seconds for the CA content to be found. It worked well. In version 8 when you click 'analyse' a progress bar progresses but no CA at all is removed.

    The 300L f4 profile does not work well, the 100-400 does. However the CA is as a result of the x2 extender. (There is very little if any CA on a 300 2.8 natively, not much with the x1.4, quite a bit with the x2 -all version 2 versions.)

    I guess if ther was a profile for the 300 2.8L lens, it would not help, but that is not the point here, it is the anaysis function that is not working under generic. (at least with my install) You cannot remove CA without a profile, which you could in v7.

    8pro 8.0.1 win 7 64 12G ram nvidia geforce 770 gtx 2G

    openCL works fine, processing very fast, no problems here.
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  • Permanently deleted user
    Raymond4:

    It's quite some time now that I had to correct for CA via Generic / Analyse and in V8 it calculates something but I couldn't detect any change. Did you notice on the Lens tab the new PF slider? Perhaps it allows for WYSIWG correction?
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  • Raymond Hearn
    The PF adjustment does not help much here as there is little PF to remove in the images. I did try it but could not see any effect.

    I still think the CF problem with generic profile is a bug. After doing a correction with a manufacturer profile (here Canon) the analysis progress bar runs then CF is corrected and the CF tick box is ticked. If you do this with generic profile, the progress bar runs but the tick box is unticked however you try to tick it. So I think this is a bug - whatever the result of the analysis progress bar does not complete or is not applied.

    I used to run generic analyse for CF on all my images. This avoided other lens profile adjustments as an issue with using a specific lens profile is that the distortion slider immrdiately jumps to 100% cropping the image. You have to then reset it to 0% on each image. This problem reverses my import setting with has a filter to set distortion at 0% to stop image cropping on import. However this is not really a problem for the odd occasion as long as one notices and resets it.
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  • Permanently deleted user
    Well, I've tested it after posting and in my case with a generic lens profile and clicking in Analyse, the bar runs and after conclusion the box is marked. However actually I'm not able to check the effect because none of my current lenses shows noticeable CA/PF. So I'm wondering a bit why in your case the box wouldn't be marked. Perhaps I'll test it again later based on some older files and report back then.
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  • SFA
    I found a file that I had processed in V7 for a small amount of CA.

    I cloned the variant then converted the clone to the V8 engine. The lens is set to Generic - it was an old FD mount 600mm and quite prone to CA and PF.


    So far as I can tell the processing is about as identical as one can get given there are some variations in the processing engines anyway. The CA effect, turning it on and off, is the same.

    HTH.



    Grant
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  • Raymond Hearn
    Thanks. I will try a few things including stopping my import distortion filter from running to see if i can get the box to stay ticked under generic as your cases.
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  • Raymond Hearn
    OK solved it for now. My input style 'distortion' - applied to all my file imports to stop cropping of the imported images, is causing this. I set input style to none and the CA controls work fine now. The style was carried forward from v7 so i will delete it and try setting it up again.

    Distortion is set to 100% and 'hide distorted area' is ticked if a lens profile is auto applied during import (in v7 at least) This can cause significant cropping, hence my work around. I will see if making a new style in ver 8 still works or causes the CA to work incorrectly.

    Ray
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  • Mark Stead
    I had a similar problem where I couldn't perform Chromatic Aberration correction on one specific photo. It turned out that this particular was shot in M-RAW on the Canon 7D. (I won't be making that mistake again...)
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  • Raymond Hearn
    I deleted my old import style for Distortion / CA /fringing & created it again. CA correction works now ok using generic or specific lens proiles. Hopefully it will stay working. However I have no idea why the original style was problematic as it worked ok through the ver 6 ver 7 upgrades. However if the fringing adjustment slider is new and was not in the older versions maybe this was the error, as information for this setting would not have been recorded in the older style.
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