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Why "0" should be Zero

Mar 24, 2012 6:53 PM

Tags: #raw #lr4
  Latest reply: Jeff Schewe, Apr 26, 2012 9:18 PM
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  • Currently Being Moderated
    Apr 21, 2012 8:43 PM   in reply to Lee Jay

    Lee Jay wrote:

     

    Mess?  Let's talk about a mess.

     

    I tried PV 2010 zeroed, and that is a massive mess.  It's like the ultimate "make my image look like crap" button - horrible skin tones, nasty colors on everything.  The only way that would be usable is if I also created a custom color profile designed for that tone curve.  The first thing I did was use the controls to undo most of what it did.

     

    The profiles and the tone curves are designed to work togethger to produce a "pleasing", rather than scientifically accurate image.  The second is really only usable for science (spectroscopy, for example).

     

    This is all a major tempest in a teapot in my opinion.  PV2010 zeroed on the top, PV2012 defaults on the bottom.

     

    I don't think anyone is recommending zeroed PV2010 for fine art reproduction, but sometimes linearized output is desirable for technical analysis and specialized purposes. Of course, this "linear" output is still gamma encoded and one must remove the gamma encoding (see the link to the ICC web site for further explanation) for a scene referred image. ACR/LR is intended more for visual editing of images than for technical analysis and more specialized tools such as DCRaw or Iris can be used when needed.

     

    If we had true high dynamic range displays, a scene referred image would look fine since it would reproduce the actual scene. However, for prints one must tone map the image so that a high dynamic range appears pleasing with a low dynamic range print. This is ably described by Karl Lang in his white paper on the Adobe web site (second link below). A simple S curve is a relatively crude method for tone mapping that is applied globally. Localized adaption is used for rendering of HDR images, but the results can appear unnatural if overdone.

     

    While many photographers (myself included) are leery of automatic corrections, if PV2012 can give me better images with less work, I am all for it. I would be more interested in learning about the image specefic adaptions that ACR/LR performs. Of course, one can currently revert to PV2010 if he doesn't like PV2012, but that option may not be available in the future.

     

    http://www.color.org/scene-referred.xalter

    http://wwwimages.adobe.com/www.adobe.com/products/photoshop/family/pro photographer/pdfs/pscs3_renderprint.pdf

     
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    Apr 21, 2012 9:11 PM   in reply to TK2142

    Do you guys ever shoot photos?

     
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    Apr 22, 2012 9:16 PM   in reply to Bill_Janes

    Just to be perfectly clear, when ACR/LR designates a Process Version, it means it will stay in place for the future (assuming Adobe stays in business). That's the whole reason for that line in the sand...

     

    With regards to PV 2012: Eric said: There are two separate ways in which PV 2012 is retrieving more highlight detail compared to PV 2010.

     

    One is the improved highlight rendering logic, when one or two channels are clipped.  This is the "auto" part which happens even at default settings (e.g., Exposure 0, Highlights 0, etc.).  Previously in PV 2003/2010, the clipped channels would simply get clipped, so tones would be lost and colors could be shifted (e.g., skies would turn from blue to cyan).  You could get PV 2003/2010 to try to repair the partially clipped colors by using minus Exposure and/or Recovery.  In PV 2012, the new logic helps to preserve tonal distinctions and prevent color shifts, and this happens even without the user touching any controls.

     

    The second way is the image-adaptive logic and new algorithms behind the controls (e.g., the tech driving the Highlights slider).  This part isn't automatic, because it only kicks in once the user starts adjusting things (e.g., setting Highlights to a non-zero value).

     

    I tended to fixate on the second explanation vs. the first...if I have incorrectly described the wan PV 2012 is working, I'm sorry...(so I guess that counts as an apology, right?)

     
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    Apr 23, 2012 3:38 AM   in reply to TK2142

    Interesting.... Has anyone who shoots panoramas, where you spend a fair amount of effort keeping exposure constant between shots had any difficulty blending panos where PV 2012 attempts to optimize differently for each image? I guess I could download the trial and find out for myself...

     

    My playing with the beta found that the optimization of white and black points worked really well for most images with the biggest exception being those where I wanted to blow out the background deliberately. And as I shoot on white virtually never these days, it's not a big drama-I suspect tweaking the lighting to ensure more thorough blow out of the background would fix this anyway.

     
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    Apr 23, 2012 3:48 AM   in reply to Susan S.

    That's a very good question!  I'll experiment when I get a chance. 

     

    My guess would be this: the auto adjustments that happen even before you touch a slider are to protect clipped highlights (and I thought blacks, though Jeff doesn't mention that above).  So they would not affect exposure and contrast of the image except right at the top (and maybe bottom) and then only to repair "damaged" parts.  Hence it would not cause problems with panoramas. 

     
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    Apr 23, 2012 9:50 AM   in reply to TK2142

    TK2142 wrote:

     

    Thanks for sharing Eric's response. Was that from private communication or did he post that somewhere?

     

    From an email exchange...

     
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  • Currently Being Moderated
    Apr 25, 2012 9:48 PM   in reply to TK2142

    TK2142 wrote:

     

    If you still disagree with me, you don't have to tell me again.

     

    The only point I would still argue is that there's a reason Eric said what he said...if you don't first set the overall tone in Exposure then you're working on an image whose overall tone is wrong. Exposure and Contrast first does set up Highlights and Shadows nicely making Whites and Blacks being relegated to fine tuning (or jumping to Curves).

     

    Note, I don't think Curves use (point or parametric) has been eliminated, but I think the need to go to curves has been reduced...

     
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    Apr 25, 2012 10:59 PM   in reply to TK2142

    Hi TK,

     

    I don't have much of an opinion about the '0' points.

     

    But have you created the lowered contrast DNG profile yet?

     

    That's a good solution for the "linear" tone curve being contrastier in PV2012.

     

    In fact, it's a good solution for anytime you want a different tonal starting point, since that way you don't have to start with a bunch of points already on the curve.

     

    But note: the tone curve in the profile does not provide the input to the basic sliders - they operate on the raw data the same way regardless of the tone curve in the profile. It's more like it sits between the basic sliders and the tone curve control in Lightroom, so to speak (or maybe "under" the Lightroom tone curve...). Anyway, one can not use a DNG profile to alter the behavior of the basic sliders, only to get a head start on tonal adjustment via the Lightroom curves, or obviate the need for it...

     

    Regarding blacks & whites:

    ----------------------------------

    - Not always a good idea to do them first, but not always a good idea to leave them till last either. The sliders in PV2012 are like a team - I rarely adjust one without adjusting one or more (or all) the others too, up until the last adjustment I mean . Like all other PV2012 sliders, blacks & whites sometimes only need small tweaks (or none), but sometimes they need big ones. They are really not the same as setting black/white point as in days of old...

     

    The original conception and intent may have been for fine-tuning, but that does not always pan out in practice, - not for me.

     

    PV2012 rocks! (except when it doesn't ).

     

    Cheers,

    Rob

     
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    Apr 26, 2012 7:36 AM   in reply to Jeff Schewe

    Jeff Schewe wrote:

     

    TK2142 wrote:

     

    If you still disagree with me, you don't have to tell me again.

     

    The only point I would still argue is that there's a reason Eric said what he said...if you don't first set the overall tone in Exposure then you're working on an image whose overall tone is wrong. Exposure and Contrast first does set up Highlights and Shadows nicely making Whites and Blacks being relegated to fine tuning (or jumping to Curves).

     

    Note, I don't think Curves use (point or parametric) has been eliminated, but I think the need to go to curves has been reduced...

     

    I agree that it makes sense get exposure right before proceeding to other corrections, but the behavior of exposure is different in PV2012 from PV2010. In PV2012 the black and white points are automatically set (within limits), and my current understanding is that one would use exposure to set the midtones. In PV2012, the exposure slider targets the midtones as shown on the LR histogram, but it is essentially a linear operator if recovery is not being performed and it also affects the highlilghts. One could then direct attention to the highlights to extract maximum tonality.

     

    In your previous LuLa ACR tutorial Thomas Knoll reported that when editing images (that would be with PV2010), he first sets the white point with exposure. The midtones might then need a correction with brightness. He stated that an alternate method would be to set the midtones with exposure, and then the white point with recovery. This alternate method appears to be needed in PV2012 since there is no brightness slider. The highlight slider does affect the midtones to some extent, but it operates mainly in the highlight region as its name indicates. Your comments would be welcome.

     
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    Apr 26, 2012 5:20 PM   in reply to TK2142

    Y'all need to be careful about applying legacy thinking to PV2012.

     

    e.g. Highlights slider sometimes pulls the white point down more than the whites slider, and sometimes not.

     

    PV2012 is not a deterministic thing that you can apply formulaic editing procedures to.

     

    Best to be loose and use the sliders as they work best on the image you are editing...

     

    That's been my experience anyway. Otherwise you'll find you have a fight on your hands when you edit images where the previous "formula" doesn't work so well...

     

    Neither whites nor exposure sets the white-point... - they work with highlights as a team to set the upper end toning...

     

    exposure & contrast & highlights & whites mostly determine upper end toning

    exposure & contrast & shadows & blacks mostly determine bottom end toning

    exposure & contrast mostly determine midtoning.

     

    Note the common ingredients - exposure and contrast are critical to midtoning, upper and bottom end toning, thus they must be right on the money to get proper tone in all three regions.

     

    Of exposure & contrast, exposure is the most critical to proper tone levels, since contrast does not alter midtone level, but exposure does.

     

    Whether you set exposure first, or whites, or both together - be sure to revisit both before you're done...

     

    Note: In PV2010 I used a "debrightened" version of Adobe Standard as default (created with DNG Profile Editor) - aimed at preserving highlight detail as much as possible.

    In PV2012, I usually use +whites -exposure.

     

    I think Adobe likes midtones to be brighter than me (and brighter than Nikon & Canon like them, judging from the difference in Adobe Standard versus the camera matching profiles).

     

    +whites -exposure in PV2012 has some of the same effect as the debrightening tone curve in the DNG profile - drops midtone level and enhances highlights.

     

    Rob

     
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  • Currently Being Moderated
    Apr 26, 2012 5:26 PM   in reply to Rob Cole

    Rob Cole wrote:

     

    PV2012 is not a deterministic thing that you can apply formulaic editing procedures to.

     

    Of course it's deterministic and formulaic.  It's just that those forumlae may be a bit less intuitive to follow, especially in edge/extreme cases.

     
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    Apr 26, 2012 5:48 PM   in reply to Lee Jay

    Lee Jay,

     

    I'm trying to share my experience of what works best for me, in case it might help somebody find what works best for them.

     

    Rather than taking one thing out of context and claiming that it's wrong, why don't you share what works best for you too?

     

    What I meant by that comment (in previous post) is: In my experience, due to the way PV2012 adapts the slider behavior for each image, and re-adapts the slider behavior again when I change exposure... that it pays to be flexible and not assume... Although PV2012 is totally deterministic to Eric Chan, for some of us, a successful procedure for editing one image does not always make for a successful formula to edit the next image...

     

    PS - Your edge/extreme cases may be other people's every-day shots...

     

    Rob

     
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  • Currently Being Moderated
    Apr 26, 2012 5:53 PM   in reply to Rob Cole

    I have.

     

    Defaults are Adobe Standard, Clarity +10, Vibrance +5, Sharpening 40, Masking 40, L-NR 40, Detail 80, C-NR 25.

     

    Set WB.

     

    If the image needs fill, use my fill-light presets.

     

    Adjust exposure, then fiddle with +shadows and -highlights until things are about right.  If the exposure was set correctly, the two numbers will be the same but opposite in sign.  If they aren't, adjust exposure.

     

    Use locals if necessary.  Done.

     

    In difficult cases, use whites, blacks, and maybe tone curve.

     
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    Apr 26, 2012 6:50 PM   in reply to TK2142

    TK2142 wrote:

     

    Lee Jay wrote:

     

    Adjust exposure, then fiddle with +shadows and -highlights until things are about right.  If the exposure was set correctly, the two numbers will be the same but opposite in sign.  If they aren't, adjust exposure.

     

    Interesting that you should use the term "fiddle".

     

    In any event, you do not seem to have images that require more sophisticated adjustments. If your approach worked for everything then Adobe should have provided just one "shadows/highligts" slider to be adjusted in conjunction with "exposure". It does not make sense to allow different values for "shadows" and "highlights" when the best setting always requires them to have the same value anyhow.

     

    I do, but they are rare.  A good 90+% of my images can be satisfactorily adjusted using this basic approach.  Every once in a while I have a pathological case that needs more fiddling.

     

    I'm not going for "effect", I'm going for "realistic".  PS is the effects tool.

     
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  • Currently Being Moderated
    Apr 26, 2012 8:42 PM   in reply to TK2142

    PV2012 allows one to tone most photos nicely, from end to end, without using the tone curve, using only 6 sliders. That would have been very hard to do without the image adaptive behavior. I'm not disagreeing with you, merely reminding why PV2012 is how it is (slider count and names were dictated from above, but how they behaved was left to developer).

     

    PS - PV2012 requires a lot less fiddling if:

    * You don't use blacks & whites sliders much

    * Your toning tastes are aligned with what PV2012 does without blacks & whites sliders.

    * You are willing to sacrifice midtone contrast to fill shadows and have highlight detail.

     

    blacks & whites are critical to almost every photo, for me.

     

    I often have -highlights with same value as +shadows, but the flexibility to have them different is critical, especially for shots where abnormal exposure will be set, since it's a primary determiner of the partition of effect between shadows and highlights sliders, and also one may simpy want midtone level to be proportionally lower or higher for some photos..., or highlights, or shadows...

     

    As the avid forumers already know, I'm a huge fan of PV2012 - not because of how straight-forward it is, but because of the results I've been able to get *after* paying my dues...

     

    Rob

     
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    Apr 26, 2012 6:57 PM   in reply to TK2142

    TK2142 wrote:

     

    LR 4.1 RC2 has added new "Defringe controls".

    Awesome!

     

     

    "UI freeze" policy

    I'm not a fan of a UI freeze policy - glad they made an exception...

     

     

    R

     
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  • Currently Being Moderated
    Apr 26, 2012 7:45 PM   in reply to Rob Cole

    X.1 versions have had feature additions before. It's X.2 and beyond that are camera/lens profile additions and bug fix versions.

     
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    Apr 26, 2012 8:00 PM   in reply to TK2142

    That's true for the X.0 release certainly. My own (well out of date) Lightroom 2 book had a 6 month print time after final edit.

     
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    Apr 26, 2012 9:18 PM   in reply to TK2142

    TK2142 wrote:

    Jeff Schewe mentioned a good while earlier that all discussions that would imply UI changes would be moot because of UI freeze (e.g., for book authors).

     

    That related to the public beta of 4.0 relative to the GM retail release of 4.0. As long as Adobe can ship new features or functionality within the quater that the app shipped,new features can be added. But that is not true between the public beta and the .0 releases...

     
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