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#81
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Lenses and sharpening
On Tue, 16 Sep 2014 09:12:12 +0100, Martin Brown
wrote: On 16/09/2014 05:37, John McWilliams wrote: On 9/15/14 PDT, 7:07 PM, Floyd L. Davidson wrote: Savageduck wrote: I got what Floyd was talking about when he was talking of high pass sharpening, and reversing it by applying the corresponding reverse parameter blur. However, he also stated above, "UnSharpMask is not reversible". My point addressed the fact that for some of us, that is not an entirely valid statement. IN an environment that supports a saved original copy so that all edits are non-destructive then that is true. You can't reverse a process if you have never executed it. If you make a copy of an image and edit it, you cant reverse the process of editing by just hauling out your original image. The edited version of the image remains edited and in most cases there is nothing you can do to reverse it. The water is muddied by the several applications which make use of a sidecar file of some kind to preserve a list of edits which are only executed when the image file is exported from the editing environment. Modifying a sidecar file by deleting an editing process from it does not make that process reversible. It merely makes that process asthough it never was. But the mathematics of blurring and of unsharp masking make it irreversible if you are only given just the processed image. (and not some hybrid Photoshop workflow encapsulated format) That is in fact a valid statement. The USM function is not reversible. That isn't a opinion, it's a fact. For one definition of the word! This seems to have degenerated into a heated and utterly pointless semantic argument over the meaning of "reversible" that is in conflict with normal image processing and mathematical parlance. A mathematical operation is reversible if a strict inverse function exists that can exactly get you back to where you started. Any operation can be made non-destructive simply by saving a copy of the original before applying the irreversible filter but that isn't very interesting. Some packages do support this sort of safe workflow. -- Regards, Eric Stevens |
#82
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Lenses and sharpening
On Tue, 16 Sep 2014 07:53:15 -0700, Savageduck
wrote: On 2014-09-16 10:36:29 +0000, (Floyd L. Davidson) said: Savageduck wrote: So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM. It's not a "reversible" workflow. The correct terms would be either a non-linear undo, or simply that it can be reverted. I guess you are in complete denial with regard to the capabilities of current versions of Lightroom & Photoshop, so it doesn’t really matter what you want the correct terms would be. I will take “reversible” out of my obviously too hyperbolic for you, description of the capabilities of those Adobe products, and just continue to use the word Adobe uses, “non-destructive”. âEUR¦and if you are going to start that reverse mathematical operation from a compressed, & lossy JPEG, good luck getting back to where you started. Your workflow, even if non-destructive, will be totally unable to deal with reverting any previous editing with the exception of processes, such as sharpen (not USM), that are reversible. It seems that you have never worked with a truly non-destructive workflow, with Photoshop and Lightroom I have a totally reversible workflow which can deal with reverting crops, spot removal, content aware fill, content aware move, any of the various grad filters available, and filters, including the notorious USM. The reason that all this argument is underway is that you and nospam fail to recognise that a "totally reversible work flow" is one thing but a reversible process is another. What Floyd has been saying is that sharpening with a high-pass filter is basically the same as Gaussian blur except that one goes forward and the other goes backwards. Whatever you do with one can be undone with the other. This is not the same as just cancelling the operation as you do when you delete it from a sidecar file. As I have said in some other responses of mine, the JPEG which might be produced is just a compressed, lossy snapshot of the actual, non-destructively adjusted, and uncompressed layered PSD, or TIF. It is best to consider it a version, and there is no point in even trying to rework it. Call it “version-1.jpg”. Once you are done with readjusting the layered PSD/TIF you can produce “version-2.jpg”, and still have the ability to return to the working PSD/TIF to produce a “version-3.jpg”. The product of a non-destructive workflow is not a JPEG, and there is little point in doing any reversion work in those JPEGs other than some polishing tweaks. Obviously there is nothing I can say or demonstrate to convince you that I am able to do what I say I can with LR &/or PS. You are stuck in a World void of Adobe where you spin your knowledge of fundamental technical minutia into a shield of denial. I will not be, nor do I strive to be the the technical wizard you obviously are, but this is one of those times where you have not moved with the times. As I said when I first came into this thread, I fully expected you to tell me I was wrong and an ignoramus (which I might well be regarding some stuff), and you met that expectation, and there isn’t much point in going any further and we should just agree to disagree, you in your World, and me in mine. You could always try to understand what he (and I) are really saying. It's not what you seem to think it is. -- Regards, Eric Stevens |
#83
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Lenses and sharpening
On Tue, 16 Sep 2014 16:36:38 -0400, nospam
wrote: In article , Floyd L. Davidson wrote: So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM. It's not a "reversible" workflow. The correct terms would be either a non-linear undo, or simply that it can be reverted. I guess you are in complete denial with regard to the capabilities of current versions of Lightroom & Photoshop, so it doesnâEUR(Tm)t really matter what you want the correct terms would be. I will take âEURoereversibleâEUR? out of my obviously too hyperbolic for you, description of the capabilities of those Adobe products, and just continue to use the word Adobe uses, âEURoenon-destructiveâEUR?. That is a good move on your part. Start sticking with what Adobe calls it, and in the process use appropriate terms. adobe didn't come up with the name. it's what everyone calls it, because it's non-destructive. But that doesn't make the processes employed reversible. As I've said, and clearly Adobe agrees with me, it is not a "reversible workflow". They provide the ability to revert an edit. That is also known as a "non-linear undo". It is not a method of "reversing" edits in the way these terms are normally used in the industry. it's not non-linear undo. it's a parametric editor and is more advanced than pixel editors. Basically you can go back to the beginning and do it right the second time. nope. that is *completely* wrong. there is no need whatsoever to go back to the beginning. you have no idea what you're talking about. But you can't reverse what you already did if it was Unsharp Mask. wrong on that too. not only can it be reversed or modified, but so can any other operation. -- Regards, Eric Stevens |
#84
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Lenses and sharpening
On Tue, 16 Sep 2014 11:01:51 -0400, nospam
wrote: In article , Floyd L. Davidson wrote: So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM. It's not a "reversible" workflow. The correct terms would be either a non-linear undo, or simply that it can be reverted. the correct term and the one used by everyone except you is a non-destructible workflow. He didn't use that term for the simple reason that that was not what he was talking about. âEUR¦and if you are going to start that reverse mathematical operation from a compressed, & lossy JPEG, good luck getting back to where you started. Your workflow, even if non-destructive, will be totally unable to deal with reverting any previous editing with the exception of processes, such as sharpen (not USM), that are reversible. wrong. in a non-destructible workflow, *everything* can be altered, adjusted or removed at any time, including unsharp mask, cropping and retouching. you've clearly never used such a workflow and are talking out your butt. -- Regards, Eric Stevens |
#85
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Lenses and sharpening
On Tue, 16 Sep 2014 01:34:16 -0700, Savageduck
wrote: On 2014-09-16 08:05:37 +0000, Eric Stevens said: On Mon, 15 Sep 2014 22:35:31 -0700, Savageduck wrote: On 2014-09-16 02:59:40 +0000, Eric Stevens said: On Tue, 16 Sep 2014 04:36:08 +0200, android wrote: In article , (Floyd L. Davidson) wrote: nospam wrote: In article , Eric Stevens wrote: All adjustments made to *Smart Objects*, in Photoshop terms, are non-destructive. I fully expect you to tell me I am wrong. I will tell you that you are discussing a point which is not the point raised by Floyd. So too is nospam, but that is not surprising. Floyd was referring to a reversible function: run it forwards and you get sharpening; run it backwards and you get blur. Or the other way around if you wish. there are indeed such functions, but that doesn't matter to users. they want to edit photos, not learn mathematical theory. when a user can modify an image and change it later, it's reversible and that's why it's called a non-destructive workflow. Squirm all you like, but USM is well known to be a non-reversible function. Oki... A reversible function and ditto workflow ain't the same thing. ;-) I doubt if nospam can get his mind around that thought. :-( You might have notice that android addressed that comment to Floyd. So what? I was agreeing with him. Not quite. You redirected the intended comment to *nospam*, If you agreed with him your snide response would have poked at Floyd. I was saying that I doubt nospam could get his mind around the thought that "A reversible function and ditto workflow ain't the same thing". The evidence is that he (and you) can't. A non-destructive workflow makes that irreversible function very reversible indeed. You are fudging word meanings. In fact you seem to be demonstrating that you too don't know the difference between a reversible function and a reversible work flow. Not at all. If you reread what I wrote below, you will see that I have a firm grasp of each of the proposed concepts in this thread. What then is a reversible process? Once that working copy has had USM applied, the layers merged, and compressed into a JPEG (a destructive action) then Floyd is correct, the function can no longer be reversed. However, Floyd doesn't see the concept of the non-destructive workflow because he doesn't, or appears not to use one. He certainly isn't using what is available to those running either Lightroom or Photoshop CS6/CC/CC 2014, and ignores that some here have the ability to take advantage of a non-destructive, or "reversible" workflow because of the software tools installed on their computers. Floyd wasn't even talking about it! He was talking about different sharpening algorithms. Floyd specifically addressed high pass sharpening (HPS) in response to Alfred's query regarding USM. We ended up discussing HPS & USM and the qualities of both. I know what Floyd was talking about. Then why are you rabitting on about non-destructive work flows? -- Regards, Eric Stevens |
#86
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Lenses and sharpening
nospam wrote:
In article , PeterN wrote: topics drift. deal with it. Learn the difference between a natural drift, and a deliberate drift to avoid a proper response to the issue. We all know yo never do that. correct. i don't. And hence you admit that you never provide proper responses, and instead merely clutter the group with nonsensical arguing. -- Floyd L. Davidson http://www.apaflo.com/ Ukpeagvik (Barrow, Alaska) |
#87
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Lenses and sharpening
On 2014-09-17 01:03:35 +0000, PeterN said:
On 9/16/2014 4:36 PM, nospam wrote: In article , PeterN wrote: All adjustments made to *Smart Objects*, in Photoshop terms, are non-destructive. true, but i was thinking of lightroom where no additional steps are required because everything is non-destructive. with photoshop, the user has to take additional steps to be non-destructive. The additional step is one click to open all objects in PS as a smart object. not always. When opening a RAW ifile in PS from ACR, when wouldn't that work? Easily done. Just remember that any content aware fill or editing cannot be done on an SO. So do the spot removal in ACR. Open as *Smart Object* after making ACR adjustments, you can always double click on that SO background layer to return to ACR and readjust. Make adjustments to taste, and save layered PSD One caveat when it comes to sharing the layered file, it is huge because of the layers. The example PSD below runs 800+MB so I won't be posting that here,unless there are individual request for email link delivery. So I end up with this in PS. https://dl.dropbox.com/u/1295663/FileChute/screenshot_905.jpg and a PSD with Smart Objects and all adjustments intact ready for any revision, saved to its very own CC folder, or wherever you want it. https://dl.dropbox.com/u/1295663/FileChute/screenshot_907.jpg Since you are not using Lightroom, to get a JPEG go to File-Save for Web. configure the JPEG dimensions, compression, etc. and Save. That is simple enough, and the working files remain intact in PS. https://dl.dropbox.com/u/1295663/FileChute/screenshot_906.jpg That results in a JPEG and I can still return to the layered JPEG to produce a different version just by tweaking/reediting or removing layers. https://dl.dropbox.com/u/1295663/FileChute/_DNC6132-SW-1.jpg -- Regards, Savageduck |
#88
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Lenses and sharpening
In article , Floyd L. Davidson
wrote: topics drift. deal with it. Learn the difference between a natural drift, and a deliberate drift to avoid a proper response to the issue. We all know yo never do that. correct. i don't. And hence you admit that you never provide proper responses, and instead merely clutter the group with nonsensical arguing. i said no such thing. you, however, will argue about even the slightest thing to avoid admitting you don't know something. |
#89
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Lenses and sharpening
On 2014-09-17 03:48:48 +0000, Eric Stevens said:
On Tue, 16 Sep 2014 09:12:12 +0100, Martin Brown wrote: On 16/09/2014 05:37, John McWilliams wrote: On 9/15/14 PDT, 7:07 PM, Floyd L. Davidson wrote: Savageduck wrote: I got what Floyd was talking about when he was talking of high pass sharpening, and reversing it by applying the corresponding reverse parameter blur. However, he also stated above, "UnSharpMask is not reversible". My point addressed the fact that for some of us, that is not an entirely valid statement. IN an environment that supports a saved original copy so that all edits are non-destructive then that is true. You can't reverse a process if you have never executed it. If you make a copy of an image and edit it, you cant reverse the process of editing by just hauling out your original image. The edited version of the image remains edited and in most cases there is nothing you can do to reverse it. You have Photoshop installed on your computer don't you? The time has come for you to actually learn how to use it. We will leave Lightroom for later. The water is muddied by the several applications which make use of a sidecar file of some kind to preserve a list of edits which are only executed when the image file is exported from the editing environment. Modifying a sidecar file by deleting an editing process from it does not make that process reversible. It merely makes that process asthough it never was. If you make the adjustments in Photoshop with a non-destructive workflow there is no use of sidecar files or catalog entries as in Lightroom. But the mathematics of blurring and of unsharp masking make it irreversible if you are only given just the processed image. (and not some hybrid Photoshop workflow encapsulated format) That is in fact a valid statement. The USM function is not reversible. That isn't a opinion, it's a fact. For one definition of the word! This seems to have degenerated into a heated and utterly pointless semantic argument over the meaning of "reversible" that is in conflict with normal image processing and mathematical parlance. A mathematical operation is reversible if a strict inverse function exists that can exactly get you back to where you started. Any operation can be made non-destructive simply by saving a copy of the original before applying the irreversible filter but that isn't very interesting. Some packages do support this sort of safe workflow. -- Regards, Eric Stevens -- Regards, Savageduck |
#90
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Lenses and sharpening
On 2014-09-17 04:08:19 +0000, Eric Stevens said:
On Tue, 16 Sep 2014 07:53:15 -0700, Savageduck wrote: On 2014-09-16 10:36:29 +0000, (Floyd L. Davidson) said: Savageduck wrote: So? The fact still remains, regardless of personal opinion about Adobe, Lightroom, & Photoshop, those using that software have the ability to maintain a fully non-destructive, and reversible workflow, that includes reversing the effects of any filter including USM. It's not a "reversible" workflow. The correct terms would be either a non-linear undo, or simply that it can be reverted. I guess you are in complete denial with regard to the capabilities of current versions of Lightroom & Photoshop, so it doesn’t really matter what you want the correct terms would be. I will take “reversible” out of my obviously too hyperbolic for you, description of the capabilities of those Adobe products, and just continue to use the word Adobe uses, “non-destructive”. âEUR¦and if you are going to start that reverse mathematical operation from a compressed, & lossy JPEG, good luck getting back to where you started. Your workflow, even if non-destructive, will be totally unable to deal with reverting any previous editing with the exception of processes, such as sharpen (not USM), that are reversible. It seems that you have never worked with a truly non-destructive workflow, with Photoshop and Lightroom I have a totally reversible workflow which can deal with reverting crops, spot removal, content aware fill, content aware move, any of the various grad filters available, and filters, including the notorious USM. The reason that all this argument is underway is that you and nospam fail to recognise that a "totally reversible work flow" is one thing but a reversible process is another. What Floyd has been saying is that sharpening with a high-pass filter is basically the same as Gaussian blur except that one goes forward and the other goes backwards. Whatever you do with one can be undone with the other. The reverse process performed on a lossy, compressed JPEG is not going to reverse the HPF to return to the original state. That was lost once the save was executed. This is not the same as just cancelling the operation as you do when you delete it from a sidecar file. We have an apples & oranges issue here I have been speaking of the two varieties of non-destructive workflow available to PS and LR users, they are not the same. What you have said above is sort of correct for Lightroom, but not for Photoshop where there are no sidecar, or catalog files. you should learn the difference. As I have said in some other responses of mine, the JPEG which might be produced is just a compressed, lossy snapshot of the actual, non-destructively adjusted, and uncompressed layered PSD, or TIF. It is best to consider it a version, and there is no point in even trying to rework it. Call it “version-1.jpg”. Once you are done with readjusting the layered PSD/TIF you can produce “version-2.jpg”, and still have the ability to return to the working PSD/TIF to produce a “version-3.jpg”. The product of a non-destructive workflow is not a JPEG, and there is little point in doing any reversion work in those JPEGs other than some polishing tweaks. Obviously there is nothing I can say or demonstrate to convince you that I am able to do what I say I can with LR &/or PS. You are stuck in a World void of Adobe where you spin your knowledge of fundamental technical minutia into a shield of denial. I will not be, nor do I strive to be the the technical wizard you obviously are, but this is one of those times where you have not moved with the times. As I said when I first came into this thread, I fully expected you to tell me I was wrong and an ignoramus (which I might well be regarding some stuff), and you met that expectation, and there isn’t much point in going any further and we should just agree to disagree, you in your World, and me in mine. You could always try to understand what he (and I) are really saying. It's not what you seem to think it is. What you claim isn’t actually 100% possible once you are trying to reverse changes to a JPEG. It might look close, but an exact reversal, never. However, I can make that exact reversal using the tools I (& you) have available in Photoshop. -- Regards, Savageduck |
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