Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: JimAscher on February 27, 2011, 03:26:48 pm
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My confusion here is principally concerned with the the options offered within Adobe products, but I am open to consideration of any relevant third-party alternatives.
As I understand it, not only can Adobe Digital Raw (ADR) captures be initially edited within ADR itself, but since Photoshop and Lightroom also incorporate the ADR engine, why doesn't any alternative or subsequent editing of a RAW (ADR) image within Photoshop or Lightroom in reality offer the same thing as within ADR, but possibly with cosmetically(?) different controls? Or are the options contained in Photoshop and Lightroom in ADDITION to those options contained in the initial ADR controls?
It is likely my confusion stems from a considerable misunderstanding of the concepts (and processing software and options) involved. I would welcome any clarification anyone can provide. Thanks.
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Hi,
I never heard about ADR. Lightroom and PS share the Adobe Camera Raw engine, with mostly cosmetic differences.
Best regards
Erik
My confusion here is principally concerned with the the options offered within Adobe products, but I am open to consideration of any relevant third-party alternatives.
As I understand it, not only can Adobe Digital Raw (ADR) captures be initially edited within ADR itself, but since Photoshop and Lightroom also incorporate the ADR engine, why doesn't any alternative or subsequent editing of a RAW (ADR) image within Photoshop or Lightroom in reality offer the same thing as within ADR, but possibly with cosmetically(?) different controls? Or are the options contained in Photoshop and Lightroom in ADDITION to those options contained in the initial ADR controls?
It is likely my confusion stems from a considerable misunderstanding of the concepts (and processing software and options) involved. I would welcome any clarification anyone can provide. Thanks.
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Hi,
I never heard about ADR. Lightroom and PS share the Adobe Camera Raw engine, with mostly cosmetic differences.
Best regards
Erik
Whoops! My mistake. Of course, I meant Adobe CAMERA Raw (ACR). Please substitute that in my initial query (which remains).
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My confusion here is principally concerned with the the options offered within Adobe products, but I am open to consideration of any relevant third-party alternatives.
Yes, you are confused...particularly the name of the raw processing in Photoshop. It's Adobe Camera Raw (ACR). ACR is a plug-in for Photoshop that allows you to render a raw capture into Photoshop. When you open a raw image, it opens first in Camera Raw for rendering. You have access to a special set of parameter adjustments–all the slider controls. Once you've set the parameters, you then render the raw file into Photoshop itself. After editing inside of Photoshop, you then save the image as a rendered file with whatever file format you need. But the original raw file is not actually altered, only the parameters. Adobe software considers the raw file to be a read only file. The parameter settings don't actually alter the pixels in the raw file...just the metadata stored either as a .xmp file (or stored in the raw file if the raw format is DNG).
Lightroom is an asset management application that stores image setting parameters in a database (although you can write the metadata out as sidecar .xmp files). Lightroom uses the same raw processing pipeline as ACR but is built into Lightroom and isn't a "plug-in" like ACR is for Photoshop. Lightroom allows you to maintain a database and export or render images for web pages, slideshows or printing. You can also open images from Lightroom directly into Photoshop for additional image editing.
The rendering of raw files from Camera Raw and Lightroom are exactly the same...however, the usability of the toolset is slightly different and the interface is considerably different. Which you should use depends entirely on the type of workflow you want. Camera Raw, Bridge and Photoshop combine for a raw processing workflow. It takes all three to have a complete workflow. Lightroom incorporates the processing into a single application–although LR can't do the same sort of image manipulations that Photoshop can do. For photographers, Lightroom is intended to be an 80/20 or 90/10 solution...it can't do EVERYTHING Photoshop can do but it can do a lot. It just depends on what your needs are.
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Phrased differently, *all* raw images must be rendered before you can work on them in Photoshop or LR. For Photoshop, that rendering takes place inside ACR. For LR, the (mostly) same ACR code is buried inside LR (ie. not a plugin) but no matter how you slice it, Photoshop itself can't directly handle RAW data, it relies on ACR to render it into something that looks like an image.
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Jeff: Yet one more time i am appreciative of your willingness and considerable ability to effectively clarify difficulties for me as i encounter them. And especially, as in this instance, so promptly. As you perhaps recall, my focus is entirely on black-and-white, and I need to determine for myself how much effort I need to (or should) put into RAW (color) processing before commencing a conversion and editing in black-and-white. Thanks again. Regards, Jim
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Phrased differently, *all* raw images must be rendered before you can work on them in Photoshop or LR. For Photoshop, that rendering takes place inside ACR. For LR, the (mostly) same ACR code is buried inside LR (ie. not a plugin) but no matter how you slice it, Photoshop itself can't directly handle RAW data, it relies on ACR to render it into something that looks like an image.
Howard; Thanks for joining in and essentially confirming what Jeff explained. I definitely am now the wiser. Jim
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For what it's worth, I just realized that my additional confusion between the acronyms ACR and ADR stem from the fact that, as a lawyer, I use ADR frequently, where in the legal realm it means Alternative Dispute Resolution. Sorry, again.
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Some times I sense that hefty doses of ADR could be useful in digital imaging web forums. :-)
Back to serious, for black and white, you can do the basic conversion from colour to B&W in ACR or Lightroom and get excellent results. The applications offer a lot of flexibility to alter grayscale tonality using the luminosity controls as well as the lightening and darkening of the grayscale corresponding with the individual colour groups which make up the image. OR you can colour correct in ACR/Lighrtroom, export to PS and do a similar conversion in PS, OR use a third party plugin in PS such as Nik SilverEfex Pro 2 which does an excellent job and provides almost an infinity of permutations and combinations you can experiment with. Starting with a colour image which is properly corrected at least for brightness and contrast before working on it in B&W is usually recommended - one way or another it will need to be done anyhow.
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... Starting with a colour image which is properly corrected at least for brightness and contrast before working on it in B&W is usually recommended....
Mark: That's what I thought, and the way I intend to proceed. I assume by your recommendation to "properly (correct) at least for brightness and contrast" includes setting the "white balance' correctly. I have access to most of the applications you cite, except I still employ the old Silver Efex Pro. I don't believe I need though at this stage to invest in the latest version 2. It's fun trying everything, but I do need eventually to "downsize' my tool-kit for a more simplified work-flow, if nothing else. Many thanks. Jim
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Mark: That's what I thought, and the way I intend to proceed. I assume by your recommendation to "properly (correct) at least for brightness and contrast" includes setting the "white balance' correctly. I have access to most of the applications you cite, except I still employ the old Silver Efex Pro. I don't believe I need though at this stage to invest in the latest version 2. It's fun trying everything, but I do need eventually to "downsize' my tool-kit for a more simplified work-flow, if nothing else. Many thanks. Jim
I haven't converted the same image to B&W with and without white balance correction to see whether it makes a difference, but WB is so easy to do in LR/ACR, no harm just doing it and starting the conversion with a colour-correct image, because those colour channels underly the B&W rendition. Versioin 1 of SEFEX Pro is fine - it's just that version 2 of course has added features you may find handy or interesting, including amongst numerous others a more efficient processing algorithm and the ability to do mixed B&W/Colour effects on the same image within the plugin.
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Mark: When I first switched from film and a wet darkroom last year, I worked with Photoshop Elements and Silver Efex Pro, relying heavily on the SEP pre-sets. The pre-sets were great in that they simplified my process as well as revealing to me many of the potentials lurking in my various digital images. This year, however, I've wanted to get away a bit from the "crutch" of the SEP pre-sets and start to manipulate my captures on my own, somewhat from scratch (from the ground up, so to speak). I turned to Lightroom (which was then within my budget), and even though LR has its own pre-sets, I didn't really use them. Now I'm considering exploring some of the more advanced tools for black-and-white processing which a full version of Photoshop (CS5) might offer, beyond those available in LR. Hence, my initial query regarding ACR and how much I need to process in RAW color before moving on to black-and-white. My question has been today very well answered in this forum, thanks to you and your fellow experts. I am now much clearer to how to proceed herein. Thanks again, and regards, Jim
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Now I'm considering exploring some of the more advanced tools for black-and-white processing which a full version of Photoshop (CS5) might offer, beyond those available in LR.
Jim - there are none. Whatever is in LR and ACR for doing colour to B&W conversions and the basic effects and variations within B&W is not exceeded in Photoshop unless you use a plugin such as SEFEX. The value-added you get in PS is all the added features and functions which don't exist in any raw converter; much of it is usable on B&W images, but not specific to B&W.
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... The value-added you get in PS is all the added features and functions ... much of it is usable on B&W images, but not specific to B&W.
Mark: Right. I'd didn't mean that I thought there were "features and functions" in PS solely for use with B&W. Just that there were "features and functions" in PS not readily (or at all) available in Lightroom that I could usefully employ in my advance(?) B&W processing. From my readings, these go under the headings of Channel Mixing, Hue/Saturation Technique, and also a B&W Stand Alone feature. If some of these can be duplicated somewhat also in Lightroom, their functionality in PS seem more refined and responsive. I, of course, may be wrong. I often am.
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Jim - there are none. Whatever is in LR and ACR for doing colour to B&W conversions and the basic effects and variations within B&W is not exceeded in Photoshop unless you use a plugin such as SEFEX. The value-added you get in PS is all the added features and functions which don't exist in any raw converter; much of it is usable on B&W images, but not specific to B&W.
Mark, this is not entirely true; I believe channel mixing approach to B&W is only available in PS.
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There's nothing you can do for B&W conversions in the Channel Mixer that you can't do with the PS B&W Adjustment Layer, and there's nothing you can do in that Adjustment Layer that you can't to in ACR/LR. The Channel Mixer approach to B&W was a long-time favorite of many photographers, but it has been overtaken by events. I think this is pretty well known, but you can test for yourself and see.
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Mark: Right. I'd didn't mean that I thought there were "features and functions" in PS solely for use with B&W. Just that there were "features and functions" in PS not readily (or at all) available in Lightroom that I could usefully employ in my advance(?) B&W processing. From my readings, these go under the headings of Channel Mixing, Hue/Saturation Technique, and also a B&W Stand Alone feature. If some of these can be duplicated somewhat also in Lightroom, their functionality in PS seem more refined and responsive. I, of course, may be wrong. I often am.
As I just reponded to Alan, using the Channel Mixture for achieving B&W effects has been overtaken with newer and more functional tools. There is a very large literature on Channel Mixing, but it predates the recent releases of PS, ACR and LR. The B&W stand-alone feature in PS you refer to is the B&W Adjustment Layer, which as I mentioned above, adds no value relative to the grayscale conversion possibilities in LR/ACR. I don't know what you mean by Hue/Saturation technique, because you wouldn't normally use that adjustment in B&W work as far as I know, but there are also hue/saturation tools in LR/ACR. Now of course, there are also the Advanced B&W drivers in Epson and Canon printers which create B&W images bypassing all these conversion techniques, but you have less control over their effects because they can't be directly soft-proofed.
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There's nothing you can do for B&W conversions in the Channel Mixer that you can't do with the PS B&W Adjustment Layer, and there's nothing you can do in that Adjustment Layer that you can't to in ACR/LR. The Channel Mixer approach to B&W was a long-time favorite of many photographers, but it has been overtaken by events. I think this is pretty well known, but you can test for yourself and see.
I don't use the channel mixer as I get pretty much the same results using the LR B&W conversion tool but there are some subtleties that can be achieved through it that make it a "different" tool. Similarly the desaturation technique used to be advocated in LR 1 because of noise caused by the B&W conversion tool but subsequent LR releases have negated the need for that approach as well (excepting some special effects).
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Whatever is in LR and ACR for doing colour to B&W conversions and the basic effects and variations within B&W is not exceeded in Photoshop unless you use a plugin such as SEFEX.
Not true...in Photoshop you can have the red, green and blue channels of a color image work as layers (technique ala JP Capnigro and myself see: Art of B&W pdf (http://schewephoto.com/workshop/Art-Black-White-DPP.pdf)) and use opacity blending and layer masks to get a B&W conversion that you can't do in LR/ACR.
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As I just reponded to Alan, using the Channel Mixture for achieving B&W effects has been overtaken with newer and more functional tools. There is a very large literature on Channel Mixing, but it predates the recent releases of PS, ACR and LR. The B&W stand-alone feature in PS you refer to is the B&W Adjustment Layer, which as I mentioned above, adds no value relative to the grayscale conversion possibilities in LR/ACR. I don't know what you mean by Hue/Saturation technique, because you wouldn't normally use that adjustment in B&W work as far as I know, but there are also hue/saturation tools in LR/ACR. Now of course, there are also the Advanced B&W drivers in Epson and Canon printers which create B&W images bypassing all these conversion techniques, but you have less control over their effects because they can't be directly soft-proofed.
A popular b+w conversion method a while back, 2 hue sat ajustment layers, the top one set to colour blend mode and the saturation set to 0, the bottom one than had the hue altered to ajust the tones. It did work but was a bit hit and miss IMHO.
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Jim
Just a few observations on the topic of B/W digital work - these are my opinion and and my experience only, and are certainly not meant to be set in stone.
* If you shoot RAW and set the camera to auto white balance, there will be no need to mess with white balance in LR or ACR for a B/W conversion. Very slight colour temperature changes will make negligible difference to the B/W result.
* If you have come to digital B/W from the wet darkroom, then Lightroom 3.x can replicate almost anything that you could have done in the darkroom for B/W (with the exception of solarisation or posterisation). You really only need CS5 if you have a wish to go beyond that.
* When it comes to the thorny issue of converting a colour RAW to B/W, you should be aware that my experience shows that any strategy other than a flat grayscale conversion will increase colour noise in the output file. This is not necessarily an insurmountable probelm, but it is something to be aware of. Noise of this type is often masked in landscape work by the nature of the subject's high-frequency detail, but it is nonetheless there.
John
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Not true...in Photoshop you can have the red, green and blue channels of a color image work as layers (technique ala JP Capnigro and myself see: Art of B&W pdf (http://schewephoto.com/workshop/Art-Black-White-DPP.pdf)) and use opacity blending and layer masks to get a B&W conversion that you can't do in LR/ACR.
I remember your paper from 2005 and went back to it. It's a great paper, but I have two observations: (i) in my remarks above what I had in mind was a direct comparison of using the channel mixer compared with using the more current techniques in LR/ACR and PSCS5 B&W Adj Layer, and (ii) yes indeed, one needs to be a bit less definitive saying what can and can't be done in PS, because - as we all know - there's really no limit. That said, it may be interesting to research with the image you used in that paper, seeing to what extent one could achieve very similar outcomes in LR/ACR versus what you show there, recognizing of course that the raw converters don't have the layering and masking capabilities of Photoshop.
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* When it comes to the thorny issue of converting a colour RAW to B/W, you should be aware that my experience shows that any strategy other than a flat grayscale conversion will increase colour noise in the output file...
Could it be that only screen rendering appears noisy?
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I remember your paper from 2005 and went back to it. It's a great paper, but I have two observations: (i) in my remarks above what I had in mind was a direct comparison of using the channel mixer compared with using the more current techniques in LR/ACR and PSCS5 B&W Adj Layer, and (ii) yes indeed, one needs to be a bit less definitive saying what can and can't be done in PS, because - as we all know - there's really no limit. That said, it may be interesting to research with the image you used in that paper, seeing to what extent one could achieve very similar outcomes in LR/ACR versus what you show there, recognizing of course that the raw converters don't have the layering and masking capabilities of Photoshop.
With the parametric editing ability of ACR/LR and the Adjustment Brush with its control point technology, much of the need for layers and masks is obviated.
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With the parametric editing ability of ACR/LR and the Adjustment Brush with its control point technology, much of the need for layers and masks is obviated.
that is if you have time to work it manually - if you have a good toolbox of plugins to automate your work then LR is quite impotent just because it does not support layers, etc directly
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recognizing of course that the raw converters don't have the layering and masking capabilities of Photoshop.
LR/ACR may be don't, but there are raw converters outside Adobe realm that have layering and masking... Bibble, Lightzone... it seems that C1 is slowly moving into that direction, albeit they lack the resources to implement fast.
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* When it comes to the thorny issue of converting a colour RAW to B/W, you should be aware that my experience shows that any strategy other than a flat grayscale conversion will increase colour noise in the output file. This is not necessarily an insurmountable probelm, but it is something to be aware of. Noise of this type is often masked in landscape work by the nature of the subject's high-frequency detail, but it is nonetheless there.
John
I don't understand this statement. When you use the raw converters (LR/ACR) to move from colour to B&W, one is engaging an instruction set making the program render the colour data in grayscale, wherein the use of the colour group sliders influences the luminance of the gray tones representing those colour groups. If this is what we are talking about, I have never ever seen any colour noise in printed images from such a process. Nor have I seen this problem in fully converted colour images converted to B&W using the Photoshop CS5 Black and White Adjustment Layer, nor have I seen it using Nik Silver Efex Pro versions 1 or 2. I've made B&W images using any of these techniques. Conversions are neutral and not showing colour noise in print sizes ranging between 13*19 and 17*22 inches. Are there other processes you have been using which do show such a problem, and if so what are those processes and in what viewing conditions do you see it?
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that is if you have time to work it manually - if you have a good toolbox of plugins to automate your work then LR is quite impotent just because it does not support layers, etc directly
Don't use plugins.
WRT other RAW editors, while there are some others out there, their functionality is limited compared to Photoshop. Even Lightzone, as good as it is, isn't Photoshop.
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Don't use plugins.
Really? Why not? Even if they do great stuff for me very easily? What am I missing here?
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I don't understand this statement. When you use the raw converters (LR/ACR) to move from colour to B&W, one is engaging an instruction set making the program render the colour data in grayscale, wherein the use of the colour group sliders influences the luminance of the gray tones representing those colour groups. If this is what we are talking about, I have never ever seen any colour noise in printed images from such a process. Nor have I seen this problem in fully converted colour images converted to B&W using the Photoshop CS5 Black and White Adjustment Layer, nor have I seen it using Nik Silver Efex Pro versions 1 or 2. I've made B&W images using any of these techniques. Conversions are neutral and not showing colour noise in print sizes ranging between 13*19 and 17*22 inches. Are there other processes you have been using which do show such a problem, and if so what are those processes and in what viewing conditions do you see it?
Mark and Slobodan
I probably shouldn't have made this comment, but I just assumed that it must be a well-known issue. Specifically, I am talking about my Hasselblad 3FR files, imported into Lightroom and converted to B/W using the grayscale conversion tools within LR. When I first started doing this, I made up a set of B/W LR pre-sets which emulate the spectral response of various B/W film stocks, and some others which replicate the effect of various coloured filters (yellow, green, orange etc). This was by no means an original idea, I simply studied how trial versions of Convert to B/W Pro and Silver Efex worked and rolled my own.
All was good, but then I started to notice that even at 100 ISO or 50 in some images I had serious colour noise in areas of flat tone and low detail. Clear blue skies are the obvious area where you see this first, and of course you only see it on screen at 100% when applying capture sharpening and noise reduction. With the 'Blad files, there is always a tiny bit of luminance noise, but normally that is no problem. One area which showed up the colour noise issue big time was skin tones in semi-shade, where massive blotchy noise was apparent. In a complex landscape with lots of grass, trees, and a cloudy sky you will barely notice a problem, as the high-frequency detail masks the noise.
Now the noise reduction in LR is very good, and will deal with the issue, but I couldn't understand why I had so much CN at low ISO. So I examined an area at 100%, and switched the file around through my presets and also back to a flat grayscale conversion (all sliders set to zero). Lo and behold, when the grayscale was set flat, the noise completely vanished. Smooth skies, smooth skin tones. Further investigation showed that the main culprit was boosting yellow and orange in the grayscale panel, which either introduces this noise or makes what CN is already there much more visible, I don't know which. And of course, the spectral response of a typical B/W film (like FP4) has this "kick" in the yellows, which gives it that look. And when I shoot B/W film, 90% of the time I have a yellow filter on as well, which in the English landscape lightens foliage and darkens skies. So all my LR presets tend to boost yellow and darken blue in varying degrees, which gives me a really nice film-like look, but also has this unforseen noise side-effect. So these days I tend to think rather more carefully about how much digital filtration to apply to a given image, and modify my pre-sets to suit.
I had just thought that all of this must be a well-known problem (except to me, of course), and I was trying to save others just starting out from finding out the hard way.
John
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John are you actually seeing colour noise or am I right it thinking it's at the noise reduction stage that you have to remove colour noise to clean up the image.
Wayne
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John are you actually seeing colour noise or am I right it thinking it's at the noise reduction stage that you have to remove colour noise to clean up the image.
Wayne
Wayne
Well, you don't actually see the noise in colour, of course, because you are working in B/W. What you see is a nasty blotchy load of gray porridge which should not be there. You see it alright at 100%, whatever you are doing. It is colour noise, because the colour noise removal in LR gets rid of it.
John
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Mark and Slobodan
I probably shouldn't have made this comment, but I just assumed that it must be a well-known issue. Specifically, I am talking about my Hasselblad 3FR files, imported into Lightroom and converted to B/W using the grayscale conversion tools within LR. When I first started doing this, I made up a set of B/W LR pre-sets which emulate the spectral response of various B/W film stocks, and some others which replicate the effect of various coloured filters (yellow, green, orange etc). This was by no means an original idea, I simply studied how trial versions of Convert to B/W Pro and Silver Efex worked and rolled my own.
All was good, but then I started to notice that even at 100 ISO or 50 in some images I had serious colour noise in areas of flat tone and low detail. Clear blue skies are the obvious area where you see this first, and of course you only see it on screen at 100% when applying capture sharpening and noise reduction. With the 'Blad files, there is always a tiny bit of luminance noise, but normally that is no problem. One area which showed up the colour noise issue big time was skin tones in semi-shade, where massive blotchy noise was apparent. In a complex landscape with lots of grass, trees, and a cloudy sky you will barely notice a problem, as the high-frequency detail masks the noise.
Now the noise reduction in LR is very good, and will deal with the issue, but I couldn't understand why I had so much CN at low ISO. So I examined an area at 100%, and switched the file around through my presets and also back to a flat grayscale conversion (all sliders set to zero). Lo and behold, when the grayscale was set flat, the noise completely vanished. Smooth skies, smooth skin tones. Further investigation showed that the main culprit was boosting yellow and orange in the grayscale panel, which either introduces this noise or makes what CN is already there much more visible, I don't know which. And of course, the spectral response of a typical B/W film (like FP4) has this "kick" in the yellows, which gives it that look. And when I shoot B/W film, 90% of the time I have a yellow filter on as well, which in the English landscape lightens foliage and darkens skies. So all my LR presets tend to boost yellow and darken blue in varying degrees, which gives me a really nice film-like look, but also has this unforseen noise side-effect. So these days I tend to think rather more carefully about how much filtration to apply to a given image, and modify my pre-sets to suit.
I had just thought that all of this must be a well-known problem (except to me, of course), and I was trying to save others just starting out from finding out the hard way.
John
If we are talking about film scanning, another idea would be to convert the image to B&W at the scan stage. For example, using SilverFast Ai6, you can select 48-bit Grayscale and it will scan and render a luminance-only image from which you will have none of these problems. You can then use an application such as Silver Efex Pro to create a multitude of B&W interpretations and effects from it.
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Yes, well film scans are another matter altogether. You don't get noise issues, you get grain aliasing instead, which is just as nasty in its own way.
There are all sorts of issues when converting colour RAWs to B/W, not all of them terribly obvious. A straight conversion is almost always very flat and far too low in contrast for for a B/W image. Very similar to the problems you have in the darkroom if you try to print a colour negative as B/W, actually. The process of normalising the histogram and bringing contrast up to a believable level (believable in the context of B/W film, that is) has the effect of increasing any inherent flaws and artefacts in the original image file.
At 100% it is often possible to see unpleasant artefacts which manifest themselves as a kind of geometric breakup of the image, which don't look like a noise problem but in fact are, and they can be smoothed using the LR colour noise removal. Usually this happens when the image has been really pushed in the shadow areas because of under-exposure in the field. Although the LR noise removal is very good, obviously it is better to do as little as possible.
John
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John, in post 29, were you talking about digital film or both?
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John, in post 29, were you talking about digital film or both?
Just digital, Mark. Specifically Hass 3FR RAW files imported directly into Lightroom 3.2 Sorry, what I wrote towards the end of the post was a little confusing. I was trying to explain why my LR pre-sets tend to boost yellow and orange - to mimic the response of film and filters. I didn't mean that I was processing film scans.
John
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Wayne
Well, you don't actually see the noise in colour, of course, because you are working in B/W. What you see is a nasty blotchy load of gray porridge which should not be there. You see it alright at 100%, whatever you are doing. It is colour noise, because the colour noise removal in LR gets rid of it.
John
I can reproduce what your getting by upping the yellow orange and reducing blue, presumably ACR see's a greyscale image in colour as far as noise is concerned, I assume it's only really rendered proper greyscale on opening in photoshop, in camera raw it's still seeing the full raw image.
Wayne
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... you don't actually see the noise in colour, of course, because you are working in B/W... It is colour noise, because the colour noise removal in LR gets rid of it.
Isn't that a good reason to use the color noise removal slider before you convert it to b&w? Btw, it is on by default, at 25 value. Are you saying you are zeroing it before the conversion to b&w?
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Could the noise be posterization?
http://www.photography.com/articles/digital-photography/posterization/
When using ACR on images with 1SO 200 - in effect no noise - and I raise saturation I find that I have to be careful when raising the blue saturation, especially in skies. The effect looks very much like posterization.
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Just digital, Mark. Specifically Hass 3FR RAW files imported directly into Lightroom 3.2 Sorry, what I wrote towards the end of the post was a little confusing. I was trying to explain why my LR pre-sets tend to boost yellow and orange - to mimic the response of film and filters. I didn't mean that I was processing film scans.
John
AH, OK, so my comment on film scans was not relevant - just wanted to verify that.
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... When using ACR on images with 1SO 200 - in effect no noise - and I raise saturation I find that I have to be careful when raising the blue saturation, especially in skies. The effect looks very much like posterization.
I hate to repeat myself, but isn't it the case of an imperfect screen/preview rendering? Meaning that if you export the image, at the same stage where you can clearly see noise/posterization, as a tiff file and open it in PS, the artifacts would not be there?
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I hate to repeat myself, but isn't it the case of an imperfect screen/preview rendering? Meaning that if you export the image, at the same stage where you can clearly see noise/posterization, as a tiff file and open it in PS, the artifacts would not be there?
The artefacts I am discussing are clearly still there once a 16-bit TIFF has been exported to PS. I zero the colour noise slider from its default of 25 before I start work on a file, because I want to carefully monitor any problems of this sort as I go along. I do my sharpening and noise reduction as the very last step in the process, before I export a TIFF or make a print. In B/W we tend to make pretty severe adjustments and manipulation of the image, probably more than one would in colour, at least to the luminance values. As in the wet darkroom, the "negative" is just the starting point. And all of these adjustments can lead to unexpected image degredation and unwanted aretefacts, but often only in a relatively small part of the picture. Because these artefacts can only be seen at 100% in LR (as with sharpening and NR), with big files like my 39MP ones, it is very difficult to keep track of what is going on, because you can only see a tiny part of the image at any one time at 100%.
Admittedly, with my 3FR files you won't see a problem in a 10x8 print. But if you print a big one you will see them alright. And our aim should always be to produce the best possible quality, surely?
John
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... I zero the colour noise slider from its default of 25 before I start work on a file...
Imho, that might be a serious mistake. Jeff Schewe will correct me if I am wrong, but there must be a reason the default is set as 25, even if the luminosity default is zero. Every raw file needs some amount of color noise reduction. By not reducing/eliminating it, you are exposing the color noise to amplification by b&w conversion. And as noise tends to be most pronounced in the blue channel, that is why you see it mostly in the blue sky. Again, imho.
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Imho, that might be a serious mistake. Jeff Schewe will correct me if I am wrong, but there must be a reason the default is set as 25, even if the luminosity default is zero. Every raw file needs some amount of color noise reduction. By not reducing/eliminating it, you are exposing the color noise to amplification by b&w conversion. And as noise tends to be most pronounced in the blue channel, that is why you see it mostly in the blue sky. Again, imho.
Slobodan
Now I am wishing I had just kept my big mouth shut and not made my first post. I was just trying to be helpful, honest . . . All I can say is, as I understand it, that NR can be applied at any stage in LR without compromising the end result. It is a parametric editor, right? All that happens is that when you export to TIFF or send to print, the app applies all the adjustments made to the image in one go, as a series of instructions. The order in which you make the adjustments has no bearing whatsoever on the final result. In many cases my Hass files need zero NR whatsover. If I shoot at 50 or 100 ISO and convert to B/W using moderate colour adjustments very often there is no visible noise anywhere in the image, or at most I need 5-10 colour NR to completely smooth things. I would usually regard 25 as overkill.
John
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...The order in which you make the adjustments has no bearing whatsoever on the final result...
Agreed. I was commenting under assumption that you, for whatever reason, refuse to apply any noise reduction.
And, of course, I have not perceived your posts as anything else but "trying to be helpful".
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Depending on what system you are using I find for RAW processing that the software the camera came with is the best to use for high quality RAW processing.
I used to work with Canon and think the results from DPP are better than lightroom/ACR. It's a clunky and frustrating program but I found the results superior in colour and tonal rendering.
Also, why Lightroom can't just give RGB colour curves like in photoshop is beyond me.
I do use Lightroom for editing and cataloguing though.
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I have been using ACR, I still can't get past the database building of LR, and prefer C1 if not other reasons, just for that. But I notice if you convert ACR to Greyscale, you lose the ability for a plugin when it's greyscale vs RGB. So you have to convert back. Wonder if there is any issues doing this, or if there is a preferred method, as I like using the color saturation and luminosity sliders in ACR before I PS it as I sometimes apply a SilvFX or other plug. Also when using color sliders in ACR with a raw file, I would think the data is used more like Channels tab as it would pull the info from the same source..no? Thoughts?..