Luminous Landscape Forum
Raw & Post Processing, Printing => Colour Management => Topic started by: Iliah on July 08, 2013, 11:00:33 am
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The theory is that as soon as the shot is white-balanced colour should be right.
Here is a simple experiment to check it. A ColorChecker SG card, shot with D4 under halogen lights, first time no filter on lens, second time with B&W KB15 (80A) color conversion filter on the lens. Matrix profiles were calculated from both shots, for delta E 2000 reports see .csv files in http://cl.ly/3x3F0D2p0e3K/D4_16-35_SG_Halogen_dE2000.zip
Sorting by the error value one can see that in both cases deep blue-green patch B7 is the worst offender but with the filter on the lens the error is very tolerable while without it it is extremely significant. Comparing error values on other saturated "cold" patches suggests that the camera will not reproduce cold colours faithfully under warm light without a compensating filter.
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Interesting. I once did a comparison between some LED and halogen floods using a D50. In that case, patch #10 was the worst for halogen, according to Adobe's DNG profile editor.
See the full test method here:
http://kronometric.org/article/lampComp/mas.html
here's the DNG Editor results, halogen at right:
(http://kronometric.org/article/lampComp/cardCompLedHalDngEd640x401.jpg)
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The theory is that as soon as the shot is white-balanced colour should be right.
True under all illumination if and only if the camera meets the Luther-Ives condition, which no commercial camera does. Changing the illumination is equivalent to changing the spectral responses of the patches. Using a filter is likewise equivalent to changing the spectral responses of the patches.
The wavelength-by-wavelength product of the filter and the illumination can be thought of as an illuminating spectrum on a camera with no filter which should produce the same results.
So, what you have demonstrated so precisely and effectively is illuminant metamerism.
Right?
Jim
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Might I suggest this fine piece by Doug Kerr: http://dougkerr.net/pumpkin/articles/Metameric_Error.pdf
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Might I suggest this fine piece by Doug Kerr: http://dougkerr.net/pumpkin/articles/Metameric_Error.pdf
Good pick, Andrew. Iliah, I know you're quite technical, so you might appreciate this more quantitative summary of digital capture and output device characterization, including a discussion of illuminant metamerism:
http://wiki.epfl.ch/edicpublic/documents/Candidacy%20exam/dcihchap5devchar.pdf (http://wiki.epfl.ch/edicpublic/documents/Candidacy%20exam/dcihchap5devchar.pdf)
It's by Raja Balasubramanian of Xerox.
Jim
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Can someone show a real world digital camera capture besides a CC chart that shows the effects of this illuminant metamerism?
Theory makes my brain hurt because I can never make a connection and/or find a use for the data to aid me in creating better looking images.
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Can someone show a real world digital camera capture besides a CC chart that shows the effects of this illuminant metamerism?
Theory makes my brain hurt because I can never make a connection and/or find a use for the data to aid me in creating better looking images.
Absolutely spot on! However some are into the theory side of things. Personally I prefer the practical side. :)
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Can someone show a real world digital camera capture besides a CC chart that shows the effects of this illuminant metamerism?
Hi Tim,
One example that's easy to grasp is that of the difference between a Red and Green wavelength light-source, which when mixed produces yellow, and a yellow wavelength light-source. Now, depending on the sensor's sensitivity to Red and Green, different sensors can produce a difference in the yellows that are perceived.
Because the human eye and the Bayer CFA use different filtered sensors, a given spectral Red/Green mix and pure yellow, will almost certainly be perceived as different yellow colors.
Cheers,
Bart
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Is this information a hindrance when you take an image? Should it stop you taking one? If the eye sees yellow differently from the camera then imo you should carry on and take the image because when I print/post to the internet the viewer of the image won't know?
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Is this information a hindrance when you take an image?
Hi,
Well, that depends if e.g. you are into accurate reproduction of artwork ... The mix of Red and Green pigments may produce the same yellow as a more pure yellow pigment, depending on the spectrum of the illuminant, and the sensitivity of the Bayer CFA filtered sensels.
In other circumstances, e.g. photo journalism, it may be less of a show stopper. It only becomes a hinderance if it's important and cannot be rectified by accurate profiling. After all, this is a forum about Color Management, so feel free to ignore if you do not care about that.
Cheers,
Bart
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It's an issue for things like product photography. You might, for example, have a product with parts made of different materials (plastic and metal, say) that are intended to be the same colour. Quite possibly the parts may be the same colour but have different reflective spectrums.
The manufacturer may have gone to some trouble to ensure that the two parts look the same colour (or acceptably close) to the eye under different common illuminants, but they may not look the same on a photographic image. No amount of global fiddling (e.g. white balance) can fix that - only local touching up.
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It's an issue for things like product photography. You might, for example, have a product with parts made of different materials (plastic and metal, say) that are intended to be the same colour. Quite possibly the parts may be the same colour but have different reflective spectrums.
The manufacturer may have gone to some trouble to ensure that the two parts look the same colour (or acceptably close) to the eye under different common illuminants, but they may not look the same on a photographic image. No amount of global fiddling (e.g. white balance) can fix that - only local touching up.
+1,
And another real world example that can not be shown for obvious reasons:
Late afternoon light has a tendency to give a very deep and rich green color to tree-leaves. A digital camera will not capture that color. It will capture a green color, but it will not have the same relative intensity and depth and is likely off in hue. I suspect this has something to do with the infrared spectrum and how that interacts with the leaves and the processes in a leave, but I am not sure. But I do know it is very visible and pronounced.
Another very distinct example: butterflies. Besides the fact that some of those butterfly wings are marvels of color and are absolutely fantastically bio-engineered from a colorreflection point of view, they also have a tendency to screw your camera's colorresponse. Circles that would be a lot of color to the eye, appear completely black on the camera. Again I suspect that this is partly due to infra-red and also ultraviolet reflectivity.
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It seems to me that the bottom line practical lesson to be learned here is that when shooting in light that deviates significantly from D50 the camera may need some help and the ex-film-shooter might do well to get that old shoe box down from the top shelf of the closet and dig out the old CC filters.
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It seems to me that the bottom line practical lesson to be learned here is that when shooting in light that deviates significantly from D50 the camera may need some help and the ex-film-shooter might do well to get that old shoe box down from the top shelf of the closet and dig out the old CC filters.
Hi,
For a 'daylight' profile, that will work just fine. It's usually a good idea to get a good quality light as input rather than trying to 'fix' things afterwards (although that's sometimes all we can do, and the result doesn't have to be that bad either).
It all starts with a good quality of broad spectrum (incandescent source) light, peaks subdued if possible. That will provide a good basis for the removal of ambient reflected light casts. But with a trichromatic capturing device, instead of a multiple (many more than three) spectral band sampling device, metamerism will always be an issue (even if we try to mimic the 3 basic eye color-matching function curves, although it would reduce the errors).
Cheers,
Bart
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Hi Andrew,
It is not exactly the usual metameric error. The catch is that the sensor is linear in respect to the power of illumination if the light is the same. If you have a series of patches with the same L and different a&b, changing the illumination and doing proper profiles will not result in same L values for different light spectrums.
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Theory makes my brain hurt because I can never make a connection and/or find a use for the data to aid me in creating better looking images.
Going back to the 80's, I did an annual report where each section was separated by a colored page curl of which I had to shoot 4x5. All the colors expect this one particular blue Pantone paper reproduced on film close enough that the art director was happy. But the blue shifted radically. I had to go out and find a lot of colors near that blue, shoot a test and find the processed film that matched what the AD wanted. It hurt my brain too, but in the end, I had to create a better looking image for the client and at the time, that was the best solution.
See if you can find some Fluorescent plastic’s of similar colors on some product, shoot it under differing illuminants and see if you find a shift between the two differing manufactured pieces that should look the same. That might help with the connections.
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Now that you mention it, OBAs in (printer)paper will eff up my camera response quite effectively.
That would be relevant if you try to use the paper for whitebalancing. Bad idea...
(Haven't tried whether a UV filter will help, but that effs up the camera response in its own magical way.)
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Theory makes my brain hurt because I can never make a connection and/or find a use for the data to aid me in creating better looking images.
I posted this before, in this thread (http://www.luminous-landscape.com/forum/index.php?topic=75548.0), which has some example images.
Ed Giorgianni once told me that, in the film days, a wedding photographer sent him a picture of the husband-to-be, the best man, and all the ushers. The image had been made on color negative film. All were wearing black tuxedos. None of the tuxedos was black in the picture. None of the tuxedos was the same color as any one of the other tuxedos. Ed said that the black aniline dyes used to dye clothing are strongly reflective in the infrared, and that the three layers of the film had some sensitivity there. The result was a disaster for the photographer.
The solution to IR problems is the same in digital capture as in the film days: UV- or IR-cut filters over the lens or the chip, or both. The IR-cut filters that come on most cameras are inadequate for some combinations of subject matter and illumination.
The IR case can be thought of as an example of the larger problem.
Jim
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I posted this before, in this thread (http://www.luminous-landscape.com/forum/index.php?topic=75548.0), which has some example images.
Ed Giorgianni once told me that, in the film days, a wedding photographer sent him a picture of the husband-to-be, the best man, and all the ushers. The image had been made on color negative film. All were wearing black tuxedos. None of the tuxedos was black in the picture. None of the tuxedos was the same color as any one of the other tuxedos. Ed said that the black aniline dyes used to dye clothing are strongly reflective in the infrared, and that the three layers of the film had some sensitivity there. The result was a disaster for the photographer.
The solution to IR problems is the same in digital capture as in the film days: UV- or IR-cut filters over the lens or the chip, or both. The IR-cut filters that come on most cameras are inadequate for some combinations of subject matter and illumination.
The IR case can be thought of as an example of the larger problem.
Jim
The more variables you setup to build your anecdote the less it provides consistently predictable, accurate and usable data to mitigate against when creating better looking pictures. Film does not come very close to reacting/recording to light as a digital sensor. Editing 3000 Raws vs about 100 scanned negatives told me that.
One of the major variables not mentioned here and in Andrew's linked Doug Kerr pdf (which offered plastic vs paint illuminant reflectance variances in kitchen devices as his anecdote) is the fact that sensors only record/measure voltage charges in grayscale that get redefined by software as color on an RGB display after those grayscale measurements go through the A/D converter. The display's RGB filtering of those grayscale pixels would have to be known and compared against the sensor's RGB spectral transmission filtering to know exactly where the errors occur.
All in all we're no where close to mitigating this issue and just resort to selective color editing as we've always done. Out of the 3000 Raws I've shot under lights of extremely varying spectra, I really never seen this as a big problem to overcome in the post processing stage. The blue/purple flower example Jim Kasson linked to doesn't really prove or point to the source of the causality with any consistency because I've shot similar flowers and sometimes they're purple and sometimes they're blue shot under the same light.
I do notice this blue/purple issue with flowers whenever I've been out too long on a hot day and my batteries are going low which points to a heat issue but still no proof or consistency in coming up with attempts to avoid or correct except in post processing.
I just think there are WAY too many variables that haven't been considered to know for sure this illuminant metamerism is the cause to consistently mitigate against.
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I just think there are WAY too many variables that haven't been considered to know for sure this illuminant metamerism is the cause to consistently mitigate against.
A camera sensor captures the light passing through the RGGB filters on it's photosite. The specific bands of color those filters pass/cut makes up the spectral response of a sensor. As far as I know, most camera sensors are currently designed to capture "daylight" or about D50-D55. The SPD of daylight is pretty specific and pretty even across the visible light spectrum. The moment a light source with a different SPD hits the sensor, the sensor's response will be different. So, that's the basic reason for the lack of a metameric match. Throw in a spiky SPD (such is the case with fluorescent lights) and the sensor response will be even different.
The whole reason that Thomas Knoll designed Camera Raw to have two separate DNG profiles; one for Standard Illuminate A (2856ºK) and a different profile for D65 was to account for the differences in the sensor's response under those two SPDs. Note that this isn't about correcting for white balance...DNG profiles are designed to correct for different spectral responses AFTER white balance has been corrected.
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The whole reason that Thomas Knoll designed Camera Raw to have two separate DNG profiles; one for Standard Illuminate A (2856ºK) and a different profile for D65 was to account for the differences in the sensor's response under those two SPDs. Note that this isn't about correcting for white balance...DNG profiles are designed to correct for different spectral responses AFTER white balance has been corrected.
The problem of course is that Camera Raw manages to obfuscate the two in a horribly incorrect way: by coupling the response profiles to the temperature slider it is effectively making it "about white balance". And then it does so incorrectly because the response is a function of SPD as you mention, but the SPD is not a function of colortemperature. (At least not the SPDs as used in DNG).
Think of it in another way: there are a lot more specific SPDs then the D or A varieties, which get no Camera Raw or DNG love. It's a convenience by oversimplification, which is fine in the RAW converter, but should not be a part of the DNG standard.
/rant over
(sorry, couldn't help myself.)
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The problem of course is that Camera Raw manages to obfuscate the two in a horribly incorrect way: by coupling the response profiles to the temperature slider it is effectively making it "about white balance". And then it does so incorrectly because the response is a function of SPD as you mention, but the SPD is not a function of colortemperature. (At least not the SPDs as used in DNG).
As opposed to an ICC profile which has a single assumption for an illuminant (usually D50) and usually is based on output referred data.
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Think of it in another way: there are a lot more specific SPDs then the D or A varieties, which get no Camera Raw or DNG love.
Yes (with a canned DNG profile) and Eric explained this quite well way back in 2010:
http://forums.adobe.com/message/3183090#3183090
Hi Andrew,
The processing order is roughly as follows. DNG color profiles contain at least a color matrix, and (optionally) one or more lookup tables, and (optionally) a tone curve. So at the minimum, there is a color matrix applied during image processing. This is applied very early in the imaging pipeline, while the image data is known to be in a linear, scene-referred space. The optional lookup tables and tone curve follow, and can be used to correct problem colors and residual issues, and apply a desired scene-to-output mapping.
Regarding white balance: It is applied along with the color matrix, i.e., very early. You can think of it as scaling the camera-native RGB coordinates till the desired values are neutral (i.e., R = G = B). This scaling, along with the color matrix in the profile, are effectively responsible for transforming from the camera-native RGB color coordinates -- which vary from model to model -- to a colorimetrically-defined system: CIE XYZ with a D50 white point, in the case of the DNG and ICC models. The user's chosen white balance is applied during this matrix step.
In the case of a dual-illuminant DNG profile, the user's chosen WB also has a second role, which is to determine how the matrices are used. As you know, Adobe's supplied "Adobe Standard" profiles are built using standard illuminants A and D65 as the calibration illuminants. So they contain separate matrices for each illuminant. The user's chosen WB determines which of the two matrices is used (more generally, how the two matrices are blended together) at image processing time. For example, if your chosen WB is Temp = 7500 K and you're using an Adobe Standard profile, then the DNG profile model calls for using the D65 color matrix. On the other hand, if your chosen WB for an image is Temp = 5200 K, then you'll be using a blend of the A and D65 matrices, with the latter more heavily weighted (since it's closer to D65 than to A). The DNG spec goes into more details on how this is done.
So to answer the question of WB and it's relevance to building & using DNG profiles: in principle, the applicability of a profile with a given WB has to do with how close the spectrum of the scene illuminant (used to photograph your real image) is to the spectrum of the illuminant used to build the profile. The closer they are, the better the results. Many flavors of natural daylight are spectrally similar (weighted differently), so this is why a daylight profile tends to work well in many flavors of daylight regardless of the actual CCT (e.g., 4700 K thru 7500 K). So even if you built your own profile under real daylight that ended up being around 6200 K, you should not hesitate to use such a profile under other similar daylight conditions, even if the CCT values vary a lot. But if you end up using a very different type of light (e.g., a fluorescent tube) then you should effect quite different, possibly unpleasant results, even if the CCT measures the same (e.g., a 6000 K office fluorescent tube).
Regarding the user's question of RGB & HSV, yes it is the same as the original definition proposed by Alvy Ray Smith. As Sandy notes there is an implementation in the DNG SDK for interested developers to use.
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What they should have done (in fact they still can) they should have build a menu with response options (like "Tungsten, Daylight, Flash, etc...") and include one option called "Auto" which would then use the temperature slider to blend between whatever they think can be blended.
Personally I think response matrices are discrete entities, and shouldn't be blended, but if convenience is your thing and as long as it is optional...
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What they should have done (in fact they still can) they should have build a menu with response options (like "Tungsten, Daylight, Flash, etc...") and include one option called "Auto" which would then use the temperature slider to blend between whatever they think can be blended.
Like this?
(http://www.digitaldog.net/files/LRWB.jpg)
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Yes, but for response, not white balance. (You see how it is obfuscated?)
This menu most likely gives you some combination of temperature and tint only, and then the underlying engine selects the blend of "Tungsten" and "Daylight" based on temperature.
So, technically you should only get "Tungsten", "Daylight", and "Auto" in a menu (for the average DNG profiles).
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Yes, but for response, not white balance. (You see how it is obfuscated?)
Not really. Maybe if I needed to understand everything happening under the hood. But I don't see the present controls having any negative effect on getting the color as I desire. Even when using a DNG profile built for daylight, selecting that or even using the WB tool, I often edit Tint/Temp to produce a rendering I prefer.
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Not really. Maybe if I needed to understand everything happening under the hood. But I don't see the present controls having any negative effect on getting the color as I desire. Even when using a DNG profile built for daylight, selecting that or even using the WB tool, I often edit Tint/Temp to produce a rendering I prefer.
Well, to refer to Eric's own example: if you select the Fluorescent option it doesn't actually give you a Fluorescent response. That would be a potential pitfall. An entirely other problem of course is the whole idea behind Temperature and Tint, which are a mathematical solution to a 2 dimensional problem, but have very little relation to the photographer's concept of tint, which is more akin to colorcast.
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Well, to refer to Eric's own example: if you select the Fluorescent option it doesn't actually give you a Fluorescent response. That would be a potential pitfall. An entirely other problem of course is the whole idea behind Temperature and Tint, which are a mathematical solution to a 2 dimensional problem, but have very little relation to the photographer's concept of tint, which is more akin to colorcast.
First off, IF I had a daylight captured image and selected Fluorescent, I'd get a less than acceptable image (IMHO) so the take home is, don't select it! That said, the setting could provide a rendering someone might like. On a few daylight captured images, it doesn't appear as I'd expect from a daylight to Fluorescent "conversion" if you will, mostly a rather cool rendering.
2nd, what you call a problem isn't one IMHO but you are welcome to call it a problem. You may have a beef with the names, fine. Once one explains what the sliders are doing, or even if one ignores the explanation of what's happening under the hood, one just moves them to get a desired appearance, all is fine (no problem). Now if you have specific images whereby the sliders fail to provide an acceptable rendering, we have an actual problem to discuss.
I can't speak for all photographers as to what they conceive for just about anything! <G>
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Not really. Maybe if I needed to understand everything happening under the hood. But I don't see the present controls having any negative effect on getting the color as I desire. Even when using a DNG profile built for daylight, selecting that or even using the WB tool, I often edit Tint/Temp to produce a rendering I prefer.
And the purity of these Tint/Temp effect perception of the overall image that has nothing to do with the effects provided by the matrices.
I was surprised to find how other apps that can edit Raw can inject their own hue/sat of Tint/Temp that differs greatly from the previews in ACR/LR combined with the actual scene which adds its own patina.
Some Raw converters (iPhoto & SilkyPix my Pentax's Raw converter) think golden hour sun has the color of dingy yellow straw while ACR/LR maintains the required level of non-linear/non-uniform "selective" saturation increase to highlight/lower mids with the right=(more realistic) blue/amber hue to mimic the effect of how the sun low in the sky actually looks shining on real objects.
Other Raw converters add somewhat of a distortion to the hues and squelch this "selective" luminance/saturation increase to highlights to keep the overall image uniform and linear behaving so when actual saturation is applied all objects whether lit by the sun or in shadow increase equally in saturation giving an overall dingy patina and less realistic appearance.
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Hi,
Well, that depends if e.g. you are into accurate reproduction of artwork ... The mix of Red and Green pigments may produce the same yellow as a more pure yellow pigment, depending on the spectrum of the illuminant, and the sensitivity of the Bayer CFA filtered sensels.
In other circumstances, e.g. photo journalism, it may be less of a show stopper. It only becomes a hinderance if it's important and cannot be rectified by accurate profiling. After all, this is a forum about Color Management, so feel free to ignore if you do not care about that.
Cheers,
Bart
Colour management isn't an end in itself, or at least it shouldn't be. Unfortunately a lot of the posts on this forum seem to lead you to think so? At the end of the day it has to/should relate to the final output. That was my point.
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Colour management isn't an end in itself, or at least it shouldn't be. Unfortunately a lot of the posts on this forum seem to lead you to think so? At the end of the day it has to/should relate to the final output. That was my point.
If you care about the subtleties and overall look of the image (patina) derived from edits and you want that level of image quality preserved for all to see and appreciate, then color management is the best thing you've got to assure this.
If that's not of major concern to you then you might as well just shoot jpegs and present them as they are straight out of the camera. No one will really know the difference.
In fact I was at my local art galleries photography section where there were quite a few prints created that way. Of course I could see from the perceptually non-uniform levels of saturation between background and foreground objects (in this case a field of flowers) subtlety, nuance and overall balance of color was not of concern and I passed it by because I couldn't stand looking at it for more than a couple of seconds.
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> Not really. ... But I don't see the present controls having any negative effect on getting the color as I desire.
The first sentence and the second do not belong together.
Really, for different light spectrum one needs a different colour transform, not different chromatic adaptation. Tint and selecting colour temperature do not solve it.
As for the second sentence, you have no option of the correct workflow, so you can't compare.
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The first sentence and the second do not belong together.
Really, for different light spectrum one needs a different colour transform, not different chromatic adaptation. Tint and selecting colour temperature do not solve it.
As for the second sentence, you have no option of the correct workflow, so you can't compare.
Oh, there really IS a problem, I and the others using this product just don't see it? And you're quite certain this is the only product I've ever used? Thanks for setting me (us) straight and uncovering this a, problem we don't recognize.
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> there really IS a problem, I and the others using this product just don't see it?
Yes, there is a problem, and you and some other users may not see it.
Other products except Nikon Capture do not automatically take into account spectral properties of the light, you need to create necessary profiles yourself.
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Yes, there is a problem, and you and some other users may not see it.
We're all color blind? We don't see it, that's true. How that makes it a problem only you can say for certain if we are to accept your premise. You'll forgive me if I don't jump off that bridge (blindly)...
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We're all color blind? We don't see it, that's true. How that makes it a problem only you can say for certain if we are to accept your premise. You'll forgive me if I don't jump off that bridge (blindly)...
Your desperate attempts of sarcasm, Andrew, are funny. But you know well from your own experience - they do not work.
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If you care about the subtleties and overall look of the image (patina) derived from edits and you want that level of image quality preserved for all to see and appreciate, then color management is the best thing you've got to assure this.
If that's not of major concern to you then you might as well just shoot jpegs and present them as they are straight out of the camera. No one will really know the difference.
Unquote
If nobody has seen the initial file then they won't know what subtleties were there? They won't - or nor will they care - what hoops you jumped through to get there. I only shoot raw - not jpegs - and a good workflow is needed. However it seems to me - and others - that some get caught up in the workflow process and think it is an end to itself. I bet you have seen - and liked - some prints that have started life as a jpeg. As you stated...No one will really know the difference. :)
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Your desperate attempts of sarcasm, Andrew, are funny. But you know well from your own experience - they do not work.
Now you're just being ridiculous! You make a point that something is broken, that thousands if not tens of thousands of users of ACR/LR can't see and don't recognize? IF you have a raw file the rest of us can examine whereby you are unable to produce a rendering and can explain this, we're all ears. Otherwise you are taking us down a faith based rabbit hole. As I said and will say again with a library of 30K+ raws all handled within the ACR engine: There's no problem on this end, I have no issues, no problems producing a rendering I desire.
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> Now you're just being ridiculous!
You just added yet another reason to trust your perception, dear Andrew ;)
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You just added yet another reason to trust your perception, dear Andrew ;)
I'll take that as no, you have nothing to back up your 'theories'. All us users are just blind to 'the problem'.
Let's put it this way, until you do so, I don't trust your perception, I suspect I'm not alone.
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I'll take that as no, you have nothing to back up your 'theories'. All us users are just blind to 'the problem'.
Let's put it this way, until you do so, I don't trust your perception, I suspect I'm not alone.
Your use of quotes is funny. Theories are theories, they may be right and may be wrong, but they do not need quotes. You like ACR, I have nothing against it. It is a fact that ACR does not allow easy ways to compensate for spectrum, and you may continue arguing as much as you wish. If you do not see it in your images, what can I say...
As far as your "I suspect..." - of course you are not. You are not alone, but that does not make you right.
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It is a fact that ACR does not allow easy ways to compensate for spectrum, and you may continue arguing as much as you wish.
You are suggesting there's a problem only you can presumably see! The facts are, I and I suspect thousands of other users have no issues producing a rendering we desire as I stated several times. You 'seem' to want to invent a problem that doesn't exist and can't provide any means to prove your point. You can continue to argue that point as much as you wish and the rest of us will use this product to produce a rendering we desire. If we can't, then we have something to discuss. I've asked two of you to provide such examples and I'm still waiting which is a tad telling. I'm not suggesting the ACR engine is perfect, far from it. I'm stating that you are inventing a problem and further, saying it's there and I (and others) just can't see it. Which is fine since if I can't see it, it's NOT A PROBLEM. Get it?
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You are suggesting there's a problem only you can presumably see! The facts are, I and I suspect thousands of other users have no issues producing a rendering we desire as I stated several times. You 'seem' to want to invent a problem that doesn't exist and can't provide any means to prove your point. You can continue to argue that point as much as you wish and the rest of us will use this product to produce a rendering we desire. If we can't, then we have something to discuss. I've asked two of you to provide such examples and I'm still waiting which is a tad telling. I'm not suggesting the ACR engine is perfect, far from it. I'm stating that you are inventing a problem and further, saying it's there and I (and others) just can't see it. Which is fine since if I can't see it, it's NOT A PROBLEM. Get it?
Well. You are turning your nervous side on.
The fact is - thousands prefer other raw converters to Adobe products, and that is because many of them do have problems producing the renditions they find believable.
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Well. You are turning your nervous side on.
If that's how you want to read it fine. It's simply your perception which like the problem you've invented, seems to be solely inside your own head. I'm fine with that!
The fact is - thousands prefer other raw converters to Adobe products, and that is because many of them do have problems producing the renditions they find believable.
Yes they do prefer other converters but for a host of reasons. That doesn't mean those who use ACR have this invisible problem you fail to illustrate! I'm fine with that too, it is simply a data point in ignoring your lack of science as faith based.
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If that's how you want to read it fine. It's simply your perception which like the problem you've invented, seems to be solely inside your own head. I'm fine with that!
Yes they do prefer other converters but for a host of reasons. That doesn't mean those who use ACR have this invisible problem you fail to illustrate! I'm fine with that too, it is simply a data point in ignoring your lack of science as faith based.
The problem is visible for those who want to see, and it is easy to demonstrate. Profile for D65, shoot under office fluorescent, compute deltaE.
As far as "the host of reasons", please give me at least 5.
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As far as "the host of reasons", please give me at least 5.
1) price
2) camera support (Sigma for one)
3) color rendition (not better or worse - but just personal taster vs effort/ability to get it)
4) certain technical aspects like : may be a particular person prefers demosaick/NR/sharpening options/blown highlights "recovering", etc)
5) certain technical aspects like : raw histogram, readouts in certain colorspaces, output to certain colorspaces, camera profiling abilities, etc
PS: #4 is clearly different from #5
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The problem is visible for those who want to see, and it is easy to demonstrate. Profile for D65, shoot under office fluorescent, compute deltaE.
Here you go. Shot under Fluorescents, using Adobe Standard profile to boot. It appears exactly as I desire, there's no problem in producing this rendering. See the Solux lights in the bkgnd which are 'warm'? Not a problem for me and easily fixed with selective editing.
(http://www.digitaldog.net/files/ACR.jpg)
As far as "the host of reasons", please give me at least 5.
1. Camera support (or lack thereof)
2. Easier to match to camera generated JPEG and use of proprietary camera metadata for proprietary camera processing
3. Tethering
4. Prefer UI
5. Performance
6. Bonus answer: anything that isn't made by Adobe (a prejudice).
Speaking of which, in terms of transparency, don't you have some vested interest in a 3rd party raw converter?
http://www.raw-photo-processor.com/RPP/Overview.html
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Speaking of which, in terms of transparency, don't you have some vested interest in a 3rd party raw converter?
http://www.raw-photo-processor.com/RPP/Overview.html
and pixelgenius is selling software for Adobe platform... 1:1
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and pixelgenius is selling software for Adobe platform... 1:1
Yes, PG does sell a PHOTOSHOP plug-in! And that's totally transparent in my case as all you have to do is click on the link in my signature and you'll see this on my web page, or look at what is reported by LuLa about me. Now try that with Iliah's link here.
(http://www.digitaldog.net/files/Bio.jpg)
That's WHY I brought up transparency, it's not about the film <g> but the person making posts.
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I purposely ignored this dE rabbit hole for the following reasons:
dE of how many colors from the scene, a few, a few hundred? Kind of makes an Avg dE report skewed depending on this selection. Colors that I know are easy to hit (paper white of the print) or far more difficult like the dark orange area's of the shirt Eric is wearing or the fellow in the red shirt next to him? If the dE values are off but I prefer the rendering, that means what? I should apply edits to produce an image who has numbers someone says are correct (based on what reference) or render the image as I desire?
Again, here's an image shot under Fluorescent with a daylight profile that appears as I wish it to appear. No problem.
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That's WHY I brought up transparency, it's not about the film <g> but the person making posts.
interested readers do know what both he & you are involved with... so that is irrelevant... on a positive side "we" (you both excluded) all can see images from both ACR/LR and RPP that "we" envy and images from both tools that "we" consider a junk ("colorwise")... so Iliah naturally tries to steer the topic to dE* to eliminate personal tastes/preferences/tolerances.
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> there's no problem in producing this rendering
Sorry not my cup of tea.
> Speaking of which, in terms of transparency, don't you have some vested interest in a 3rd party raw converter?
http://www.raw-photo-processor.com/RPP/Overview.html
And? What is my interest? How vested is it?
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Transparency... LOL
> 1. Camera support (or lack thereof)
> 2. Easier to match to camera generated JPEG and use of proprietary camera metadata for proprietary camera processing
> 3. Tethering
> 4. Prefer UI
> 5. Performance
> 6. Bonus answer: anything that isn't made by Adobe (a prejudice).
before:
>1) price
> 2) camera support (Sigma for one)
> 3) color rendition (not better or worse - but just personal taster vs effort/ability to get it)
> 4) certain technical aspects like : may a particular person prefers demosaick/NR/sharpening options/highlights "recovering", etc)
> 5) certain technical aspects like : raw histogram, readouts in certain colorspaces, output to certain colorspaces, camera profiling abilities, etc
> PS: #4 is clearly different from #5
That is funny.
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I purposely ignored this dE rabbit hole for the following reasons:
dE of how many colors from the scene, a few, a few hundred? Kind of makes an Avg dE report skewed depending on this selection. Colors that I know are easy to hit (paper white of the print) or far more difficult like the dark orange area's of the shirt Eric is wearing or the fellow in the red shirt next to him? If the dE values are off but I prefer the rendering, that means what? I should apply edits to produce an image who has numbers someone says are correct (based on what reference) or render the image as I desire?
Again, here's an image shot under Fluorescent with a daylight profile that appears as I wish it to appear. No problem.
True reason is that converters do not stand the test. None of them, unless a specific profile is possible.
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interested readers do know what both he & you are involved with... so that is irrelevant...
I don't see how you can speak for all LuLa readers. I do know one of us has decided to provide much information about themselves, the other as little as possible. It's irrelevant because you feel it is, but please let other's speak for themselves.
on a positive side "we" (you both excluded) all can see images from both ACR/LR and RPP that "we" envy and images from both tools that "we" consider a junk ("colorwise")... so Iliah naturally tries to steer the topic to dE* to eliminate personal tastes/preferences/tolerances.
Yet no examples of the invisible problem I am unable to detect. Do you really think the vast majority of photographers who process their raw files wish to eliminate personal tastes/preferences/tolerances?
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Yet no examples of the invisible problem I am unable to detect.
The image you just posted is a perfect example of the problem, and not just this one.
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The image you just posted is a perfect example of the problem, and not just this one.
Sure it is, sure it is... Despite the fact that I as the image creator have no issues with it. You're losing credibility as you keep typing. I'd say let's agree to disagree but you've done so little to express your point I don't know what to disagree with! You've invented a problem that doesn't exist except for those who believe you based on blind faith. You are of course entitled to your opinion but not your own facts. Time to move on unless you can, as requested, provide a sample of this problem anyone reading these posts can evaluate on their end.
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> You're losing credibility as you keep typing.
Sorry Andrew, but it is the other way around.
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Transparency... LOL
> 1. Camera support (or lack thereof)
> 2. Easier to match to camera generated JPEG and use of proprietary camera metadata for proprietary camera processing
> 3. Tethering
> 4. Prefer UI
> 5. Performance
> 6. Bonus answer: anything that isn't made by Adobe (a prejudice).
before:
>1) price
> 2) camera support (Sigma for one)
> 3) color rendition (not better or worse - but just personal taster vs effort/ability to get it)
> 4) certain technical aspects like : may a particular person prefers demosaick/NR/sharpening options/highlights "recovering", etc)
> 5) certain technical aspects like : raw histogram, readouts in certain colorspaces, output to certain colorspaces, camera profiling abilities, etc
> PS: #4 is clearly different from #5
That is funny.
Sorry not my cup of tea.
This is the kind of response one expects from 'true believers' who's faith based opinions divert from those who simply ask for actual examples to understand the potential issues. We've been told there is some problem with the ACR engine. We are told we can't see it. I was asked to provide an image captured in a fixed way, processed in ACR. It was ignored or course (not my cup of tea). That I the image creator have no issues with the rendering is ignored and the so called problem is said to be there but can't be illustrated. We are asked to provide examples of why people would use other raw processors, more than the requested examples were provided and of course, ignored. The poster assumes I only use one raw processor (wrong again), and I can't see the problem that I can't see but that's of course my fault. Iliah ignores the fact that his level of transparency is as little as one could provide here. One simply needs to go to the link I provide where more negative opinions about raw processors are found but little facts to backup the opinion. What a waste of time! At least Iliah is amused.
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Andrew, why not to invite some of your friends here to help you out?
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Andrew, why not to invite some of your friends here to help you out?
Sure Iliah...what would you like me to say...that you have a long history on multiple forums and email lists of being very anti-Camera Raw and dismissive of Thomas Knoll's approach to raw processing. Does that help flush out the background? It would als be useful for LuLa members to know that you've work with Alex Tutubalin on LibRaw (http://www.libraw.org/) and Andrey Tverdokhleb on RPP (http://www.raw-photo-processor.com). You are also a strong critic of Camera Raw on Dan's Color Theory email list. So, it's not like you are just some guy voicing an opinion here...you have an axe to grind.
But, one thing you haven't done (as far as I can see) is explain what's wrong with Thomas' approach.
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Sure Iliah...what would you like me to say...that you have a long history on multiple forums and email lists of being very anti-Camera Raw and dismissive of Thomas Knoll's approach to raw processing. Does that help flush out the background? It would als be useful for LuLa members to know that you've work with Alex Tutubalin on LibRaw (http://www.libraw.org/) and Andrey Tverdokhleb on RPP (http://www.raw-photo-processor.com). You are also a strong critic of Camera Raw on Dan's Color Theory email list. So, it's not like you are just some guy voicing an opinion here...you have an axe to grind.
But, one thing you haven't done (as far as I can see) is explain what's wrong with Thomas' approach.
I knew you would chime in, and thank you for the links. However I do not "work". I answer when being asked when it comes to RPP. LibRaw is a free and open source initiative to help maintain diversity of raw converters which IMO is in the best interest for all of us photographers. Good competition never hurts.
While you are in ad mode, why not to mention RawDigger? It is a very useful utility for those who want to know their cameras better and polish exposure technique.
Saying I have an axe to grind you need some better proves than you provided :) All I want is some good raw converter, Adobe or not, and spend as little time as possible out of my photography.
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One simply needs to go to the link I provide where more negative opinions about raw processors are found but little facts to backup the opinion.
technically that might be written by AT (the person who originally started RPP, not IB, who joined that later when, as far as I understand, another project, Rawmagick, prematurely died)...
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While you are in ad mode, why not to mention RawDigger? It is a very useful utility for those who want to know their cameras better and polish exposure technique.
I was going to mention RawDigger (http://www.rawdigger.com/) but didn't know you had anything to do with it...(other than use it).
:~)
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to know that you've work with Alex Tutubalin on LibRaw (http://www.libraw.org/)
that is quite irrelevant to any axes grinding... LibRaw refactors (along with certain performance improvements, etc, etc) dcraw code into C++ library, which makes it easier for 3rd party developers to use that Coffin's creation, and Adobe also does contribute to dcraw as their employees said on record and vice versa...
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> the person who originally started RPP
Ask Andrei, I'm sure he will explain.
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I was going to mention RawDigger (http://www.rawdigger.com/) but didn't know you had anything to do with it...(other than use it).
:~)
Read copyrights, you may find a dozen other projects with my name on them.
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> you have a long history on multiple forums and email lists of being very anti-Camera Raw and dismissive of Thomas Knoll's approach to raw processing.
Dismissive? Anti-Camera Raw? Or simply pointing out problems?
And why you guys, being friends of late Bruce (G-d bless him) never corrected technical inaccuracies in his CameraRaw article? I pointed those out many times.
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Dismissive? Anti-Camera Raw? Or simply pointing out problems?
What problems?
10 posts from Iliah since I posted the image he asked for, nothing yet on what the visible or more likely invisible problems are. That has to be a record in digressions in this short a period of time.
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And why you guys, being friends of late Bruce (G-d bless him) never corrected technical inaccuracies in his CameraRaw article? I pointed those out many times.
Which Camera Raw article?
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What problems?
10 posts from Iliah since I posted the image he asked for, nothing yet on what the visible or more likely invisible problems are. That has to be a record in digressions in this short a period of time.
I asked for deltaE report to keep it objective.
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Which Camera Raw article?
http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/products/photoshop/pdfs/linear_gamma.pdf
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I asked for deltaE report to keep it objective.
Not at all necessary for the reasons I outlined and further, you yourself have stated:
The image you just posted is a perfect example of the problem, and not just this one.
So what's so visually obvious and in what way does this dismiss my preference for the rendering I the image creator desired?
Again for the 3rd or fourth time, WHAT PROBLEM?
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What part of Bruce's article do you disagree with?
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What part of Bruce's article do you disagree with?
Read carefully, count sections on distribution scales, use your current understanding to rephrase or comment on "Linear processed raw captures look very dark."
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Not at all necessary for the reasons I outlined and further, you yourself have stated:So what's so visually obvious and in what way does this dismiss my preference for the rendering I the image creator desired?
Again for the 3rd or fourth time, WHAT PROBLEM?
That does not work for me. Compute deltaE and we will not be arguing impressions.
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That does not work for me. Compute deltaE and we will not be arguing impressions.
Poor and expected excuse. Understood clearly, it's an invisible problem as I suspected. Probably why you dragged me down that "show us an image" rabbit hole then decided that despite my expected and desired rendering, that couldn't be dismissed.
Further, without those dE values that are in this context quite useless, how do you explain what you wrote more than once, that the example was obviously a "perfect example of the problem"? Making up facts again?
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Read carefully, count sections on distribution scales, use your current understanding to rephrase or comment on "Linear processed raw captures look very dark."
Linear data without a profile to define it does look dark! I have plenty of examples of this as I'd hope you do too.
If that's the biggest beef you have with Bruce's article, I'd place that into the silly beef you have with invisible issues with the ACR engine.
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> Poor and expected excuse.
Andrew, again - other way around. You opted out and it is the obvious fact. I'm amazed how uninterested you are in this simple experiment.
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Andrew, again - other way around. You opted out and it is the obvious fact. I'm amazed how uninterested you are in this simple experiment.
It's up to YOU to prove there's an issue here and you haven't and apparently can't! The image is rendered as I desire, period. No dE values will change that fact. You are the one who raised this so called ACR problem but have zero proof to back up the claim. This isn't about copy work or producing an output referred image that somehow colorimetrically matches the scene! It's about creating an image as I desire and I've done that despite being shot under Fluorescent's with a daylight profile. Your demand. So the ball is in your court. You have this idea there's some issue with the ACR engine and DNG profiles built one way, shot under some illuminate. Prove your point. Based on the digressions you've made just today, doesn't seem possible. But I still have an open mind.
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That does not work for me. Compute deltaE and we will not be arguing impressions.
Note to self:
Ignore Iliah's postings from now on for they're a big waste of time to read. Iliah, you have not contributed anything of substance or use to this discussion as far as what I can gather for myself.
You've totally lost credibility with me for sure.
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> Linear data without a profile to define it does look dark!
Any, not only linear gamma image may look bad if proper profile is not assigned.
If matching profile is not assigned a wrong one is necessary assigned. Images may look green, over or underexposed, dark, bright,...
You Andrew being colour management proponent should know better than discussing the looks of images without profiles.
Simple thing, add a comment to Bruce's article to avoid those who did not know him seing him in a wrong light. Instead you are arguing here.
And while you will be on it, read carefully, do your best.
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> Iliah, you have not contributed anything of substance or use to this discussion
Apart from starting it :)
> You've totally lost credibility with me for sure.
Do you have mine?
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> It's up to YOU to prove there's an issue here and you haven't and apparently can't!
I like the mistake you are making :)
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> You've totally lost credibility with me for sure.
Do you have mine?
Frankly my dear I don't give a shit!
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Any, not only linear gamma image may look bad if proper profile is not assigned.
Maybe it will, depends on the data (like all the images on the web without a defined profile in sRGB). Further, I've yet to see any color space without a profile that looks as dark as a linear capture without a assigned profile. But the bigger issue is again, you take us down this rabbit hole, now with Bruce's article which is correct: The image will look dark without the profile.
Simple thing, add a comment to Bruce's article to avoid those who did not know him seing him in a wrong light. Instead you are arguing here.
Unnecessary. If the image is untagged, it looks dark. In the context of the article and how ACR operates, you'll never get an untagged image out of it. You are again nit picking when it isn't necessary but fail to address big issues like your concept that ACR has some problem which you cannot illustrate.
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Frankly my dear I don't give a shit!
Why do I?
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> Unnecessary.
Necessary.
> If the image is untagged, it looks dark
Depends on my settings.
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[/b] The image is rendered as I desire, period.
PS: Andrew, so next time do not come swinging about ICC profiles :-) because your logic can justify anything.
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I'll get to the point because now I've found an image example that Iliah needs to study concerning color metrically accurate scenes vs pleasing color...
http://www.janblencowe.com/resources/img/blog_img/4152/CarryingPLaceCrop.jpg
Examine the color rendering character in the digital capture and compare to the "pleasing centric" color rendering in the painting especially in the shadows. This is what Kodak color scientists studied and grappled with when they were deciding on what type of dyes and processes to implement in order to determine whether to render colorimetrically accurate or pleasing results when first coming out with color film processes. They noticed actual colored scenes look different viewed colormetrically accurate on a static 2D surface compared to the actual scene. Big problem if you want to sell film processes.
Since "pleasing rendering" was a subjective concept they decided to study the works of famous photo realistic color paintings such as Vermeer, Rembrandt, etc. in order to understand what "pleasing" color comprised because these were all they had to go on.
There is a lot of optical trickery going on in a painting that doesn't follow exact DeltaE definitions. I studied those optical tricks and understand why they're implemented and is what I see happening when I edit using ACR's color engine. It's just not as pronounced.
Now did I waste your time with that bit of FYI? Can you paint a photorealistic painting on a 2D surface and make it look 3D? I can and until you do you don't know what the hell you're talking about. PERIOD!
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> I've found an image example that Iliah needs to study concerning color metrically accurate scenes vs pleasing color
So you learned something new from that image. Better now then later. Unfortunately the digital part of it looks exposed and processed in a wrong way.
Thing is, we discuss here the tool we apply, and that tool is supposedly accurate colour transform, the starting point. Arguments like "I see it that way" simply do not cut here.
> This is what Kodak color scientists studied and grappled with when they were deciding on what type of dyes and processes to implement in order to determine whether to render colorimetrically accurate or pleasing results when first coming out with color film processes.
I'm afraid your understanding on what Kodak scientists were doing and what goals they were setting is a slight oversimplification and overgeneralization.
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the "pleasing centric" color rendering in the painting especially in the shadows. T
pleasing ? painting is absolutely horrible... if your are similar then :-\
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PS: Andrew, so next time do not come swinging about ICC profiles :-) because your logic can justify anything.
The logic is to dismiss what was written and not proven:
Yes, there is a problem, and you and some other users may not see it.
It's the writing of what I think now of a religious zealot what has no ability to prove his point. Worse, when asked to produce an image as specified, he tells us that: The image you just posted is a perfect example of the problem, and not just this one.
He then suggests that we (I) need to prove that there isn't a problem! There hasn't been one iota of proof to this claim. Then we're taking down another digression of his design about Fraser's article which is a sure sign this person can't prove his point. There may very well be an issue with the ACR engine, but I'm not going to buy that, based on my use of the product until I see demonstrable examples and that's not happened. Again, IF there is a problem, where is it in the image I posted? It appears as I want it to. My logic therefore demands either proof of the problem or I'm going to go my way and dismiss the nay-sayer if you don't mind.
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So you learned something new from that image. Better now then later. Unfortunately the digital part of it looks exposed and processed in a wrong way.
So you have some dE values to prove that or this is your subjective interpretation?
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So you have some dE values to prove that or this is your subjective interpretation?
Tim Lookingbill has them because he (Tim) was claiming that it (digital capture) was "color metrically accurate"... shall be so (to accurately capture "pleasing" painting)
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> I've found an image example that Iliah needs to study concerning color metrically accurate scenes vs pleasing color
So you learned something new from that image. Better now then later. Unfortunately the digital part of it looks exposed and processed in a wrong way.
Thing is, we discuss here the tool we apply, and that tool is supposedly accurate colour transform, the starting point. Arguments like "I see it that way" simply do not cut here.
> This is what Kodak color scientists studied and grappled with when they were deciding on what type of dyes and processes to implement in order to determine whether to render colorimetrically accurate or pleasing results when first coming out with color film processes.
I'm afraid your understanding on what Kodak scientists were doing and what goals they were setting is a slight oversimplification and overgeneralization.
Yikes! You really do need to win an argument at all costs that include embarrassing yourself with lame, pointless comebacks like that.
I had to over simplify Kodak scientist's studies because it's too big a subject to explain all the complexities of why judging color rendering performance through the static eye of a spectro in terms of DeltaE doesn't take into account the adaptive nature of human perception that is the cause for coming up with "pleasing color" over accurate when viewed on a 2D surface.
Got any more lame comebacks?
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Tim Lookingbill has them because he (Tim) was claiming that it (digital capture) was "color metrically accurate"... shall be so (to accurately capture "pleasing" painting)
The question wasn't addressed to Tim as I hope you're aware. It was addressed to the Iliah who claims there's this issue we can't see but presumably would accept my preferred rendering if provided some dE values of which I could easily create to prove my point as I illustrated (how dE values can be skewed). Iliah has made a comment about the exposure and processing of Tim's supplied image based on some visual interpretation yes? Yet when presented another image captured as he demands, he can't point out the issues he says exists and needs dE values. Kind of two-faced and convenient depending on how you wish to dismiss proving a point.
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Yikes! You really do need to win an argument at all costs that include embarrassing yourself with lame, pointless comebacks like that.
I had to over simplify Kodak scientist's studies because it's too big a subject to explain all the complexities of why judging color rendering performance through the static eye of a spectro in terms of DeltaE doesn't take into account the adaptive nature of human perception that is the cause for coming up with "pleasing color" over accurate when viewed on a 2D surface.
Got any more lame comebacks?
I don't think that Iliah has anything against your right to inflict any amount of color damage to our eyes with what you consider "pleasing", he however states that before such damage shall be inflicted it is a nice (or rather the only right) idea to get dE part right and then start hurting our eyes from that point onwards... just my 2c, I might be wrong.
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Yikes! You really do need to win an argument at all costs that include embarrassing yourself with lame, pointless comebacks like that.
You are being too kind to call it an argument at least based on this definition:
In logic and philosophy, an argument is an attempt to persuade someone of something, by giving reasons for accepting a particular conclusion as evident.
So far, nothing provided has been even close to evident. We're dealing with a faith based concept, not one expressed with any demonstrable facts.
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Tim Lookingbill has them because he (Tim) was claiming that it (digital capture) was "color metrically accurate"... shall be so (to accurately capture "pleasing" painting)
No, I didn't say the digital capture was color metrically accurate. I said notice the differences (the alternating hues) in the color renderings of shadow detail in the painting compared to the digital capture.
It's the differences that point to an understanding about optics (in the painting) established by the masters on how to render color that would appear to have depth and three dimensionality that is not in the original scene=colormetrically accurate.
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It's the differences that point to an understanding about optics (in the painting) established by the masters on how to render color that would appear to have depth and three dimensionality that is not in the original scene=colormetrically accurate.
I am sorry - paining looks very flat to me...
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> I had to over simplify Kodak scientist's studies because
you do not know those studies.
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Below shows on the left a colormetrically accurate=(exactly what my eyes saw) version of food items I shot under 100watt GE Soft White tungsten bulb using my Pentax K100D's Tungsten WB preset and viewed with ACR's defaults.
I couldn't believe how ugly the image looked because when I kept looking back at the scene next to my display the food looked fresher and more vibrant. That's because my eyes already adapted to the amber color cast of the 2800K tungsten lights.
To support the adaptive effect as the cause for the mismatch I turned away and stared into a dark corner under the table not lit by the tungsten bulb and waited for my eyes to adapt and then looked back at the scene and sure enough I got a match between the ugly ACR preview shown in the sample below and the actual scene.
The scene changed color so how the heck is DeltaE numbers going to help me if my eyes don't see what a spectro does.
Now I had to make the image look "pleasing" (version on the right) but didn't know where to start because the actual scene now looks like crap. I had to use my memory of the colors I saw of greens, reds and tans from lettuce, tomato hamburger buns I saw in old '90's Dairy Queen commercials of flying hamburgers and DQ ice cream cones and manipulated the HSL tables and WB to trick the eye into seeing fresher looking food. Spectros can't do that so DeltaE's are useless.
My point behind this is that ACR's tools are simple and act on the color in such a way that deliver quicker "pleasing" results when relying on edits similar to this in order to fight the adaptive effect. Other Raw converters I've used do things to the color with regard to hue/sat and WB during edits that makes this a slower process for me.
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So you have some dE values to prove that or this is your subjective interpretation?
Red channel on the palm blown out prematurely.
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Red channel on the palm blown out prematurely.
What? From what image, the one downloaded from the web page? Don't see it. I see all three channels blown out in the sky area (so what)?
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> From what image, the one downloaded from the web page? Don't see it
That explains it all.
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> From what image, the one downloaded from the web page? Don't see it
That explains it all.
Nah!...My last post explains this subject better than all your posts combined.
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I am sorry - paining looks very flat to me...
Well, the purpose of the thing was a little different http://www.janblencowe.com/blog/maine-plein-air-landscape-painting-a-meritorious-entry/
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Nah!...My last post explains this subject better than all your posts combined.
Yes, "a colormetrically accurate=(exactly what my eyes saw)" made my day.
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> From what image, the one downloaded from the web page? Don't see it
That explains it all.
You make lots of assumptions and pass em on as fact (like the primary issue you have conveniently ignored all day, this "problem" with ACR). That may fly when you post on DP Review, but doesn't wash with the LuLa audience as well. Anyway, you wrote:
Unfortunately the digital part of it looks exposed and processed in a wrong way.
You have Tim's raw? If not, you once again made a big assumption and passed it off as a fact. You could have no way to know anything about the exposure. It could have a stop or more latitude. Hence my question to you (From what image, the one downloaded from the web page?) which you conveniently haven't answered, like most of the questions presented to you. Again, you have the raw? You're making points about exposure and development based on Tim's post to the web? Is this yet another digression (like the one on the Fraser piece) to ignore your lack of any facts presented here in terms of this invisible ACR problem?
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Here's another demonstration of how some Raw converters follow colormetrically accurate constructs of color appearances that shows up in their edits I see quite a bit and is the reason I like ACR's color engine which bases its color appearances with regard to contrast and densities from a more color purity construct.
Below are links to two versions of subtractive color mixing samples of cyan, magenta and yellow which were first established and implemented into color film processes and dyes.
The first is an actual photo of these purities in the form of individual filters viewed on a light table...
http://www.cis.rit.edu/fairchild/WhyIsColor/images/SubtractiveColorDisks.jpg
The link below is a synthetic RGB representation of the same filtering process and color mixing with special attention to densities and how more richer they appear than the ones above...
http://www.jiscdigitalmedia.ac.uk/images/cmy_01.gif
If you had a choice between the two colorants and their palettes in order to create a painting, which of the two would you choose? I pick the synthetic version for its more dense and rich colors in the shadows and vibrance in highlights which mimics the behavior of very expensive dyes on paper including inkjets.
If you can't figure this out from this, then you're just too dense to teach to.
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> You have Tim's raw? If not, you once again made a big assumption
I do not need the raw to know exposure is off on this one (if there even was a raw), and I also know that perfect exposure was never the goal for this shot. I know this shot was measured "evaluative", and it can't be perfect. By the features of the image I can say I doubt the camera can record raw, as it must be a rather compact one; and being compact it should not allow a lot of DR to get the whole scene DR into the shot without help of filters, especially given the fairly high sensor density.
I did not download the web image, I see no need for it. But you can, and if you will - select R255 and see. For me the colour gradation on the palm is enough to say red is saturated above correct, and some red must be at full 255. And also, if you will download - check EXIF.
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Yes, "a colormetrically accurate=(exactly what my eyes saw)" made my day.
Yes as defined by lining up the Lab numbers to the CCchart pictured below which is colormetrically accurate by the numbers as well as visually accurate. That's what I mean when I make the connection when a machine's numbers actually match up to what I see which is rare because my eyes keep adapting to every scene I photograph which are not CC charts.
Did that make your day?
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Here's another demonstration of how some Raw converters follow colormetrically accurate constructs of color appearances that shows up in their edits I see quite a bit and is the reason I like ACR's color engine which bases its color appearances with regard to contrast and densities from a more color purity construct.
again - there are a lot of nice images from ACR, but a lot of shitty ones ("I see quite a bit")... says nothing about ACR, more about the person behind it... the same it true about other raw converters.
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Yes as defined by lining up the Lab numbers to the CCchart pictured below which is colormetrically accurate by the numbers as well as visually accurate. That's what I mean when I make the connection when a machine's numbers actually match up to what I see which is rare because my eyes keep adapting to every scene I photograph which are not CC charts.
Did that make your day?
we are getting close... now an actual raw file shot under a regular domestic (like some average Joe has hanging somewhere) fluo coupled with conversion parameters (ACR) & Adobe Standard (from OEM distribution) will certainly put a nail in Iliah's coffin.
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we are getting close... now an actual raw file shot under a regular domestic (like some average Joe has hanging somewhere) fluo coupled with conversion parameters (ACR) & Adobe Standard (from OEM distribution) will certainly put a nail in Iliah's coffin.
Getting close to what? I don't understand what you're getting at.
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Boiling this quarrel down to real problems, the only one I can see is that ACR engine determines which profile to use from the color temperature, specified at development stage. It means that:
- it would use the profile built for daylight for shots made under LEDs or cold fluorescent lights;
- it would use the profile built for daylight for shots made in twilight or in open shade, where CCT is much higher than 6500K and color shifts are already noticeable;
- it would use some mixture of two profiles for shots made under warm flourescent lights, which do not resemble neither tungsten nor daylight;
- it would use some mixture of two profiles depending on the color cast that its user finds pleasing at the moment and introduces using WB slider.
Worse, this way of using profiles is embedded into DNG specification.
On the other side, the engine allows us to use any single-illuminant profile we want to use. So this seems to be a problem only for uneducated users who, as usual, are left to enjoy the results of the process they do not completely understand.
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I do not need the raw to know exposure is off on this one
Of course you don't. You just assume and speculate and pass it off as a fact. You can't have any idea about the camera original, raw or JPEG without having the camera original. But why go down another of your digression designed rabbit holes? In the course of one day, you've provided at least three examples of making things up and passing them off as facts, the most egregious being the original flat earth theory you continue to ignore: the invisible 'problem' with the ACR engine that we can't see. We'll skip the awful mistakes you had to correct numerous times in Bruce's piece (being friends of late Bruce (G-d bless him) never corrected technical inaccuracies in his CameraRaw article? I pointed those out many times) when what he wrote isn't incorrect. Now we are to believe that simply viewing a web image, you know all about the capture, exposure and processing of an image without even looking at it's histogram. Basically the bread crumb trail you've built in writhing here is easily dismissed as you are unwilling to back up your assumptions with fact. That leads me to believe, for the first time on this forum, you have a significantly large BS factor! So why go on? When (IF) you can get back OT and show us how the image I posted as per your request is a perfect example of the problem, and not just this one, I'll attempt to examine if you've provided an ounce of science or a pound of BS. Based on all your postings today, the later would not surprise me a lick.
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Boiling this quarrel down to real problems, the only one I can see is that ACR engine determines which profile to use from the color temperature, specified at development stage.
ACR/LR doesn't determine this, it's a setting that is sticky OR someone sets it (upon import with a preset etc). And of course anyone can change this profile at any time. But yes, someone can set a profile that's inappropriate for the capture as I did using a daylight profile shot under Fluorescent light (and there was no negative issue I could see after white balancing and applying tint/temp season to taste). So this so called ACR problem is a huge mystery to me and apparently Iliah who can't explain it other to say it's there. A problem that is valid that you point out are users who do things they shouldn't or as Vladimirovich correctly states, produce shitty images due to a lack of understanding how to use the product.
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The problem, from my point of view, is providing dual-illuminant profile as a simple solution to the problem that has no simple solutions.
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The problem, from my point of view, is providing dual-illuminant profile as a simple solution to the problem that has no simple solutions.
One doesn't have to use dual illuminant profiles but further, where's the actual problem? Is it a problem that is rare or very common and if the later, where are all the complaints?
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One doesn't have to use them. But most people use them, and most people do not know it.
And those who do know seem to think that using dual-illuminant profile and setting "correct" white balance is enough to get a decent rendition of colors.
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> You just assume and speculate
No, I see. You may need EXIF.
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> You just assume and speculate
No, I see. You may need EXIF.
Wrong again! I did see the EXIF data, it doesn't let you off the hook one bit. As usual, you fail to read what I've written: You can't have any idea about the camera original, raw or JPEG without having the camera original.
You don't have the camera original. You have zero idea what was done to the image in terms of processing. You assume as usual. And you continue to keep moving down this path to digress from your original silly idea about this ACR "problem" you can neither illustrate or identify.
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Yes as defined by lining up the Lab numbers to the CCchart pictured below which is colormetrically accurate by the numbers as well as visually accurate. That's what I mean when I make the connection when a machine's numbers actually match up to what I see which is rare because my eyes keep adapting to every scene I photograph which are not CC charts.
Did that make your day?
sRGB rendition of CC24 can't be colorimetrically accurate as it exceeds sRGB gamut. The image has no value without the actual raw and repeatable steps.
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Wrong again! I did see the EXIF data, it doesn't let you off the hook one bit. As usual, you fail to read what I've written: You can't have any idea about the camera original, raw or JPEG without having the camera original.
You don't have the camera original. You have zero idea what was done to the image in terms of processing. You assume as usual. And you continue to keep moving down this path to digress from your original silly idea about this ACR "problem" you can neither illustrate or identify.
Good that you saw it. Now is it Tim's image? Could it be shoot in raw? Is there any burnt red on the palm? Was this image to demonstrate any accuracy, even an accurate representation of the painting?
Sometimes one can't judge exposures without looking at original, sometimes one can.
Your talk in regards to this image here http://www.luminous-landscape.com/forum/index.php?topic=80130.msg647205#msg647205 saying
"You have Tim's raw? If not, you once again made a big assumption and passed it off as a fact. You could have no way to know anything about the exposure. It could have a stop or more latitude. Hence my question to you (From what image, the one downloaded from the web page?) which you conveniently haven't answered, like most of the questions presented to you. Again, you have the raw? You're making points about exposure and development based on Tim's post to the web? Is this yet another digression (like the one on the Fraser piece) to ignore your lack of any facts presented here in terms of this invisible ACR problem?"
is obviously showing lack of attention. It is as close to original as it can be because original is most likely OOC JPEG.
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Good that you saw it. Now is it Tim's image?
Why not ask Vladimirovich who wrote first:
Tim Lookingbill has them because he (Tim) was claiming that it (digital capture) was "color metrically accurate"... shall be so (to accurately capture "pleasing" painting)
Could it be shoot in raw?
Nope, but that's pointless as I said later as you can't speak to the processing since you do NOT have the camera original.
Is there any burnt red on the palm?
Not that I see (not that it matters).
Was this image to demonstrate any accuracy, even an accurate representation of the painting?
I don't know what the point of the image is. I know you can't make any points about how it was captured or processed and I know this is yet another unnecessary digression you've continued to discuss to presumably ignore the bigger issue, your idea that ACR has a problem you continue to fail to address!
Sometimes one can't judge exposures without looking at original, sometimes one can.
And sometimes pigs can fly, so what?
At what point will you address the actual issue: this invisible problem with the ACR engine?
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Yes as defined by lining up the Lab numbers to the CCchart pictured below which is colormetrically accurate by the numbers as well as visually accurate. That's what I mean when I make the connection when a machine's numbers actually match up to what I see which is rare because my eyes keep adapting to every scene I photograph which are not CC charts.
Did that make your day?
That's a pretty good calibration, but hardly colorimetrically accurate. The image is in sRGB, and as Iliah has pointed out, patch 18 (cyan) is out of the sRGB gamut. According to Bruce Lindbloom the sRGB values for that patch are -49, 135, 166 and you have 0, 140, 175. Shown below are analyses of your rendering according to Imatest. What you do not seem to understand is that the sensors of our cameras do not meet the Luther-Ives criteria and metameric error occurs. You can optimize the matrix for some colors under a given illuminant (in this case for the color checker), but other colors not shown in the chart (as purple with flowers) will be off. What Iliah showed in his original post is that metameric error with tungsten illumination can be reduced with an 80a filter and this can be documented by DeltaEs. For art reproduction and scientific photography where accurate color is the goal, this could be useful. His useful observation was sidetracked by your and others' rants about accurate and pleasing color. Kodachrome strove for accurate color but many photographers preferred Velvia for landscapes and Astia for portraits. Generally, most photographers like increased saturation but hue shifts are less welcome. For artistic rendition, pleasing color may not even be desirable.
Bill
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sRGB rendition of CC24 can't be colorimetrically accurate as it exceeds sRGB gamut.
Interesting. Could you please post the reference for that statement and tell us what "it" is referring to?
Please don't side-step the question . . .
All the patches on my mini-card are in-gamut except for cyan. As are the patches on Norman Koren's sRGB simulation . . .
(http://kronometric.org/phot/gamut/ColorCheckerKoren_sRGB.jpg)
[edit] I see Bill posted similarly to the above while I was typing . . . [/edit]
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All the patches on my mini-card are in-gamut except for cyan. As are the patches on Norman Koren's sRGB simulation . . .
I also see this (only Cyan OOG in sRGB) but before we go farther, we need Tim to let us know if he's referring to sRGB or that's just what he used to post his image to the web. It's possible his testing was done in a larger color space whereby Cyan would fall into gamut and as expected, sRGB was posted for a web page.
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I also see this (only Cyan OOG in sRGB) but before we go farther, we need Tim to let us know if he's referring to sRGB or that's just what he used to post his image to the web. It's possible his testing was done in a larger color space whereby Cyan would fall into gamut and as expected, sRGB was posted for a web page.
Maybe so, but in any event the orange is in sRGB gamut and has a delta E even larger than the cyan. The image is not a perfectly colorimetric rendering as Tim claimed. He does not seem to appreciate metameric error.
Bill
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I also see this (only Cyan OOG in sRGB) but before we go farther, we need Tim to let us know if he's referring to sRGB or that's just what he used to post his image to the web. It's possible his testing was done in a larger color space whereby Cyan would fall into gamut and as expected, sRGB was posted for a web page.
My posting the CCchart got totally taken out of context of my original point and now is being scrutinized as some kind of empirical scientific evidence of a representation of split hair accuracy errors in relation to the numbers and how they appear in sRGB space.
According to Eric Chan, the actual CCchart Lab numbers can be off by as much as 5 points in either channel before you can see a substantial color difference or for it to have a noticeable effect on a wide range of images applying the DNG profile that created the slightly off CCchart numbers. I meant it as a loose guide to define what I consider colorimetric accuracyfrom a visual perspective more so than by the numbers in defining ACR defaults for my camera. And if you want to argue that go talk to Eric.
And of course the "painting held in hand in front of the actual scene shot with what I'm guessing is a P&S camera" I linked to was also taken out of context of the point I was trying to make which was to illustrate optical tricks implemented in painting techniques to imbue a 3D effect to a 2D image that the ACR color engine employs only not so pronounced. But I see nobody picked up on that and I doubt any of you ever will so I'm done here cuz' I'm not going to repeat myself here anymore. You either get it or you don't.
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to imbue a 3D effect to a 2D image that the ACR color engine employs only not so pronounced. But I see nobody picked up on that
no takers for snake oil... "ACR color engine" is as capable to produce (in certain hands) dull images as quite opposite ones and so do other raw converters.
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no takers for snake oil... "ACR color engine" is as capable to produce (in certain hands) dull images as quite opposite ones and so do other raw converters.
Show us an example.
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> My posting the CCchart got totally taken out of context
Where is the raw?
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Bill, I would start my analysis with checking light uniformity and geometrical flatness of the card.
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> He does not seem to appreciate metameric error.
It is not just metameric error what I encounted because using LUT profiles one is getting much smaller deltaE.
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Your assumption that for this image raw is needed to judge the exposure is wrong, isn't it?
> And sometimes pigs can fly, so what?
Really? In raw?
> Not that I see
Well, you just said it.
> At what point will you address the actual issue: this invisible problem with the ACR engine?
All in good time. But it will not help as the way ACR treats images won't change.
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But it will not help as the way ACR treats images won't change.
Bullshit bud...while it's true that Thomas won't change things based on crackpot, half-baked ideas, Thomas is certainly willing to make major and substantial changes if somebody can prove to him he should...PV 2003 was the original pre DNG profile process version...which didn't change till PV 2010 which incorporated a lot of changes.
Then in PV 2012, a complete wholesale change to the processing was added. I would count this as proof positive that the ACR/LR engineers WILL make changes, sometimes massive, if somebody can prove what they are doing can be improved. Apparently, you've been unsuccessful in proving that to Thomas. I wonder why? Could it be your approach? Or could it be that Thomas doesn't think too much about your rants? In my experience, Thomas is almost always right, except when you can prove him wrong and then he's willing to turn on a dime because Thomas really does want to do the right thing...
Thomas has a track record...he co-authored Photoshop, he was the founding engineer on ACR and worked closely with Mark Hamburg in developing Lightroom...these guys have a proven track record and in effect, created this whole friggin' industry...you gotta have some stones to want to go up against the likes of those guys. So far, I don't think you match up. I'll back Thomas over you.
BTW, as to your OP, the results should have been self-evident...of course a capture under tungsten with LB filters would produce a better result than trying to WB a tungsten shot. DOH...so, yes, you original question has been proven. All the rest has been mental masturbation...something you are good at.
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> while it's true that Thomas won't change things based on crackpot, half-baked ideas, Thomas is certainly willing to make major and substantial changes if somebody can prove to him he should
We will see.
> Then in PV 2012, a complete wholesale change to the processing was added. I would count this as proof positive that the ACR/LR engineers WILL make changes, sometimes massive, if somebody can prove what they are doing can be improved.
And who was that? Themselves?
The change of the main idea of interpolating between 2 profiles - I do not see it coming before 2018.
> Apparently, you've been unsuccessful in proving that to Thomas
> BTW, as to your OP, the results should have been self-evident
For me - yes. For many photographers attempting to profile using HomeDepot halogens - apparently no.
> All the rest has been mental masturbation...something you are good at.
You realize of course how thick is my skin, yet you waste time trying to get under it :)
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You realize of course how thick is my skin, yet you waste time trying to get under it :)
No, I'm not trying to get under your skin...I just want other readers to be able to grok what you are doing. Some people don't know you and your tactics...I do. Next?
BTW, Sorry I didn't respond to your assalt on Bruce's article...my wife and daughter decided today would be a good day to see The Lone Ranger...pretty good movie.
As to what Bruce was a bit foggy on was the fact that he presumed that linear exposure had some sort of relationship with levels in a 12-bit linear capture vs actual photons captured. But remember, Bruce wrote this in 2004...very early on in the whole digital capture business and was trying to explain linear vs gamma encoded color spaces. I'm pretty sure Bruce would have something different to say today. Sadly, he's not here to explain himself...personally, I'm inclined to let what Bruce wrote stand on it's own terms. Where possible, I've tried to extend and expand on what I think Bruce thought. But I'm not Bruce...nor are you–not even close.
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> I just want other readers to be able to grok what you are doing
They need your help? LOL
> Sorry I didn't respond to your assalt on Bruce's article
It was not an assault by any means and any standards. Knowing me as you claim you should have known better. Maybe you just don't know me :)
Since the article is on-line, and normal user knows to set PS colour settings to ask when opening on missing profiles, a comment not to make the article look wrong would help. Certainly a technical inconsistency with the number of separating lines on gradients for linear and gamma-corrected distributions should be taken care of too.
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It was not an assault by any means and any standards.
Yes it was...your pointing to Bruce's writing came out of left field and had nothing to do with you OP...so, you agree that doing a CT correction in a digital capture is useful for better color accuracy? Regardless of the raw processing engine being used? I just want LuLa members to get something positive from all this verbal diarrhea...you know, giving the members something to do to improve their output?
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> Yes it was...your pointing to Bruce's writing came out of left field
It is just a simple demonstration that you guys are defending your mistakes and avoid making corrections even when the mistakes are plain obvious, even for the sake of the good memory of your late dear friend.
> you agree that doing a CT correction in a digital capture is useful for better color accuracy?
Funny you should say that. Since year 2000 I practice that, and posted many times on that topic. While "useless filters" comments are still flooding in 2013.
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While "useless filters" comments are still flooding in 2013.
Care to point to any posts where I said doing proper color correction of the taking light source was "useless"? I seriously doubt you'll find any since I advocate optimal raw capture parameters where possible. Since sensors are generally optimized for daylight (do you disagree) and capture at less than the optimized light source will produce suboptimal results. Agreed?
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It is just a simple demonstration that you guys are defending your mistakes and avoid making corrections even when the mistakes are plain obvious, even for the sake of the good memory of your late dear friend.
Careful bud...I don't take potshots at Bruce lightly. You want to rewrite what Bruce wrote in 2004 for 2013, go right ahead. But you better be real careful...what Bruce was trying to explain was the difference between film and digital captures...you got anything useful to add to that? Do so...Otherwise, shut up...get it? It would be useful if you had anything useful to add vs crap you want to use to distract.
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> Care to point to any posts where I said doing proper color correction of the taking light source was "useless"?
I hope you did not; but maybe you can point to any your posts saying those are necessary? It would be certainly a useful reference for those who want to avoid problems.
> Since sensors are generally optimized for daylight (do you disagree)
Generally yes, but not all of them, for example D4 is optimized for a little different spectrum, starting from 5800 and up to about 3800, including HMI and other types of lights commonly found on arenas. Some Canon models also tailored for arenas better then others.
It is important also to realize that spikes in the spectrum are not very well corrected with filters, and camera sensors are generally optimized for continuous spectrums.
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> You want to rewrite what Bruce wrote in 2004 for 2013
No. I think some comments and explanations are due. The article itself is very good and also has historical value. It should not be edited, maybe apart from that technical issue with separators. But even that I would think has its place in comments.
Now, the problem of raw vs. film is usually that people are not comparing apples to apples. From certain perspective raw is a latent positive image, and should be compared to latent film image which is also mostly linear.
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It is important also to realize that spikes in the spectrum are not very well corrected with filters, and camera sensors are generally optimized for continuous spectrums.
Correct...obvious if somebody had half a clue about sensor response to various light sources...which you could have advocated in your OP.
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Correct...obvious if somebody had half a clue about sensor response to various light sources...which you could have advocated in your OP.
Quite a lot of shots under office FL lights are taken using shutter speeds of 1/200, 1/100 (in USA with 60Hz mains freq.). Next folks wonder why they have very different WB and very different resulting colour rendition even after correcting WB. I guess a lot of explanations is needed. People tend to trust that "cameras know what they are doing"
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> At what point will you address the actual issue: this invisible problem with the ACR engine?
All in good time.
I do not see it coming before 2018.
Why not invite some of your friends here to help you out?
Tim, don't close the door behind you, I'm coming!
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Some general responses to your general statements:
Quite a lot of shots under office FL lights are taken using shutter speeds of 1/200, 1/100 (in USA with 60Hz mains freq.).
I see that "office" FL lighting is expected to have range of 2:1 lux in USA? Your reference, please?
Next folks wonder why they have very different WB and very different resulting colour rendition even after correcting WB.
Could you try to clarify the above rather confusing statement? Under what circumstance is "very different" WB obtained?
For example, my SD9 and SD10 Sigmas are usually set to sunlight. Whatever that is in deg K and tint, it is fixed and not "very different". In fact not different at all. Works for all the shots I take around here - no incandescent lighting anywhere. Any glaring color inaccuracies are fixed to my satisfaction in post - or the shot is sent to the trash.
Could you please quantify "very different resulting colour rendition" in concrete terms, e.g. delta-E's? After all, one man's meat is anothers poison; horses for courses; etc; etc.
I guess a lot of explanations is needed
They're all out there on the Web. Go Google or Bing or Yahoo or Alta-Vista (remember that one?).
<People> tend to trust that "cameras know what they are doing"
With tongue firmly in cheek, I'd say that readers of this forum are not instances of members of your set <People>.
Perhaps: Pedants tend to distrust anything that the camera does. I am one such ;)
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> I see that "office" FL lighting is expected to have range of 2:1 lux in USA?
Not what I said.
> Could you try to clarify this rather confusing statement?
If shutter speed is set incorrectly and the light is from FL lights powered at 60Hz consecutive shots have different WB and different colour rendition after correcting WB.
> It's all out there on the web
And lots of it is wrong.
> readers of this forum are not instances of members of your set "People"
Rule #6
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> I do not see it coming before 2018.
Hehe
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>I see that "office" FL lighting is expected to have range of 2:1 lux in USA?
Not what I said.
My apologies. You said 'shutter speeds of 1/200, 1/100'. Did that imply a ratio of possible office illuminance or something else? Obviously I did not understand the generalization. Please clarify.
> Could you try to clarify this rather confusing statement?
If shutter speed is set incorrectly and the light is from FL lights powered at 60Hz consecutive shots have different WB and different colour rendition after correcting WB.
> It's all out there on the web
And lots of it is wrong.
I could be glib and say "And lots of it is right" but does it not go without saying that cognoscenti such as ourselves will make the right judgement?
> readers of this forum are not instances of members of your set "People"
Rule #6
Too terse for me, I have no idea what that means.
You might make more headway in persuading this forum that (effectively) what comes out of the camera is not what went in if you would use full sentences, give credible references, post illustrative images and refrain from using phrases like "mental masturbation" (even if provoked).
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> mental masturbation
Jeff used it. I never even think of using such words.
> You might make more headway in persuading this forum that (effectively) what comes out of the camera is not what went in if you would use full sentences, give credible references, post illustrative images
I made a post providing data and description of what was done. Most of the discussion that followed is offtopic and in a lot of cases it is out of the line.
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> mental masturbation
Jeff used it. I never even think of using such words.
Oops. Shame on Jeff, then ;)
> You might make more headway in persuading this forum that (effectively) what comes out of the camera is not what went in if you would use full sentences, give credible references, post illustrative images
I made a post providing data and description of what was done. Most of the discussion that followed is offtopic and in a lot of cases it is out of the line.
That you did, but I was talking about all of your posts and your literary style. If you see nothing wrong with those, then "as ye sow, so shalt thou reap" ::)
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> "as ye sow, so shalt thou reap"
When in Rome
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> "as ye sow, so shalt thou reap"
When in Rome ..
. . do [your imaging] as the Romans do ;D
Happy sowing and reaping, I'm bowing out for now to give the heavy-weights a chance.
'Bye
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Before you leave, is my point with FL lights clear?
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Before you leave, is my point with FL lights clear?
My understanding is that you're telling the forum that setting the shutter period to more than the flicker rate of the lamps is bad practice.
TTFN,
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One can use 1/30 (not always practical), 1/60 (may be too long as well), or 1/120.
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One can use 1/30 (not always practical), 1/60 (may be too long as well), or 1/120.
Indeed one could. You said "FL lights". Would your advice apply also to modern lamps with electronic ballasts?
From Wikipedia:
Fluorescent lamps using high-frequency electronic ballasts do not produce visible light flicker, since above about 5 kHz, the excited electron state half-life is longer than a half cycle [citation needed], and light production becomes continuous. Operating frequencies of electronic ballasts are selected to avoid interference with infrared remote controls. Poor quality (or failing) electronic ballasts may have insufficient reservoir capacitance or have poor regulation, thereby producing considerable 100/120 Hz modulation of the light.
(my bolds)
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> Would your advice apply also to modern lamps with electronic ballasts?
If one can't check the lamps operate at high freq. - yes.