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New Examples of useless Auto CA removal

Mar 10, 2012 3:14 PM

I thought that I would post a clear example of how the Auto CA removal is quite useless for some images. This feature is clearly not capable of handling the task compared to manual adjustment in LR3.

Please make a quick update to return manual CA adjustment, as this inadequacy is enough to make LR4 unusable for me.

Frogfish LR4.jpgFrogfish LR3 crop.jpgFrogfish LR4 crop.jpg

You can easily see the blue and yellow fringing and some ugly halos in the LR4 auto corrected version. This is a real step backwards. Please fix it!

 
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  • Currently Being Moderated
    Mar 10, 2012 3:47 PM   in reply to scubamarli

    scubamarli wrote:

     

    I thought that I would post a clear example of how the Auto CA removal is quite useless for some images.

     

     

    Well, the new Auto CA is designed to fix lateral CA which is the inability of a lens to have all colos of light the exact same size at the sensor. The other type of CA is longitudinal CA (see this info about CA)  which the inability to focus all colors of light at the same plane. In lookin at your image, it sure seems like you've got longitudinal CA which the Auto CA isn't designed to fix. In point of fact, the old manual CA sliders couldn't really fix longitudinal CA either...although some times you could do some good or kinda hide it. Don't know if you shot the image in a tank or underwater housing...but as I recall, CA has always been a problem shooting through ports. The refaction index of water really adds to optical defects when shooting underwater. Nice shot BTW...

     

    I do know the engineers are also working on longitudinal CA correction although I have no idea on time frames...I think this would be a good example image to send to the engineers. Eric Chan would be the guy...I'll let him post and directions for sending the files. Note, they really need raws, trying to fix CA in jpegs isn't realy as good. Also note that they would only use the files for internal testing...they're pretty good about that.

     
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    Mar 10, 2012 6:23 PM   in reply to scubamarli

    Manual doesn't work for axial/longitudinal either.

     

    I'm thinking people are using it anyway to sort-of mask longitudinal CA with the entirely wrong type of correction, and being happy with the results anyway.

     
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    Mar 10, 2012 6:37 PM   in reply to Lee Jay

    Lee Jay wrote:

     

    I'm thinking people are using it anyway to sort-of mask longitudinal CA with the entirely wrong type of correction, and being happy with the results anyway.

     

    Lee Jay...yep. I don't disagree with the fact that longitudinal CA can be "improved" with the manual sliders, even if it can't actually be "fixed". At this point the solution is either bring back the old manual sliders in the Manual Lens Corrections panel or also work to fix real longitudinal CA as well as lateral CA...there's another form of longitudinal CA which even the old manual sliders could not really fix and that is the old purple fringing problem.

     

    But I do think shooting a wide'ish angle underwater shot through a domed port tends to radically change the nature of the CA...it's what I would call a hybrid CA that I guess isn't getting the Auto CA solutions correctly. Which is why I think it's really, really important for Eric Chan to get examples.

     

    I understand the OP's situation (I used to do a lot of underwater stuff but back in my film days) and it's a really unique environment with unique technical issues...which while being edge cases, doesn't make them any less important, just not mainstream...

     
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    Mar 10, 2012 6:44 PM   in reply to scubamarli

    scubamarli wrote:

     

    I am puzzled by these responses. Any kind of fringing is unacceptable to my eye. The end result is what matters. Are you guys suggesting that the LR4 version above looks better than the LR3? Quite frankly, I don't care about whether it's the "right or wrong type of correction." It looks better without fringing and halos. The LR4 version is bad.

     

    No...what we are saying is the problem you have in your images are not what the new Auto CA was designed to fix. Believe me when I say the engineers are not interested in making bad stuff...but the problems you are facing are unusual...underwater photography presents a whole different set of problems than above water shooting (particularly the way lenses perform).

     

    Rest assured that the engineers are interested in addressing issues and improving image quality for all images. That's why getting example images to the engineers is important. I realize you are frustrated...we'll have to wait and see what happens. In the meantime, as far as I know, the LR3 manual controls will be repected if you don't update to PV 2012 (even if the old manual control UI is gone).

     
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    Mar 10, 2012 6:51 PM   in reply to scubamarli

    scubamarli wrote:

     

    By the way, this is with a flat port, so there is much less distortion than with the dome and a wide angle. This is shot with a Nikon 105mm macro lens for which Adobe has no profile, even though it is still a very popular lens.

     

    Even a flat port will introduce substantial optical distortion and lens defects because of the refractive index or water (fresh water is different than salt water) compared to in-air lens performance. Even if Adobe had a lens profile for arial use, it would not be the same underwater...as far as I know, nobody has done lens profiles underwater :~) Really, your situation is different...underwater shooting is, well, a really different set of problems (as I'm sure you are aware).

     
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    Mar 10, 2012 6:59 PM   in reply to scubamarli

    scubamarli wrote:

     

    I doubt if anyone would suggest that Auto is a better setting for taking photos than Manual, Aperture or Shutter Priority, or even Program. With the ability to fine tune so much in Lightroom, why fix something that isn't broken?

     

    It was broken.  (Click the image and watch).

     

    CA-correction-comparison.gif

     
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    Mar 10, 2012 6:59 PM   in reply to scubamarli

    scubamarli wrote:

     

    If you look around the forums, there are examples of land photography with the same issue. It is not just going to affect underwater shots.

     

    Actually, no...the issues are not the same. Longitudinal CA is a different animal...what your particular issue is really a hybrid. Currently the Auto CA can't really fix your problem nor can it fix a pure longitudinal CA , sorry. Again, as soon as Eric can chime in and give you a place to send images, I can't really offer you any help…I just want to make you and other understand what's going on. Really, the engineers do want to the best image processing possible…I just can't give you a time table on when (or if) they can address the issues in LR4. Above my pay grade...

     
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    Mar 10, 2012 6:58 PM   in reply to scubamarli

    scubamarli wrote:

     

    Why remove a popular feature?

     

    Because in most cases, the new one is far superior to the old one.

     
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    Mar 10, 2012 7:03 PM   in reply to scubamarli

    scubamarli wrote:

     

    By the way, here's the land photos;

    http://forums.adobe.com/message/4257919#4257919http://

     

    Yep, that's pure longitudinal CA (with little if any lateral CA). That's a prime example of what the Auto CA was not designed to fix. If you look at the images posted compared to yours, the problems are different...

     
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    Mar 11, 2012 10:52 AM   in reply to scubamarli

    scubamarli wrote:

     

    So, to reiterate, Auto CA removal does not work well.

    Did it work well in the example I posted above?

     
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    Mar 11, 2012 6:41 PM   in reply to scubamarli

    "Examples of useless Auto CA removal"

    "This feature is clearly not capable of handling the task compared to manual adjustment in LR3."

    "Well, I was quite happy with the results using the manual sliders as were a lot of other photographers. It certainly looks a lot better."

    "So, to reiterate, Auto CA removal does not work well."

     

    I'm just pointing out that blanket statements of that sort are, well, wrong.

     

    It's certainly possible that, in some cases, the manual or profile approaches work better, but in general that is not true.

     
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    Mar 12, 2012 11:53 AM   in reply to scubamarli

    Please send the raw file of this image to madmanchan2000@yahoo.com (you can use yousendit or similar).  This will allow Eric (of the Adobe Camera Raw team) to examine it.

     
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    Mar 12, 2012 3:35 PM   in reply to scubamarli

    The new auto CA clearly does not work as well as the previous implementation in my experience and is a step backwards. It was very apparent to me as soon as I started to use it.

     
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