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Author Topic: Red River Palo Duro Etching matte paper on Epson 3880 - first look  (Read 5560 times)

Josh-H

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #60 on: July 12, 2017, 08:49:52 PM »

"Why ? Few observers will be wearing polarized sunglasses !

It's pretty simply - for creating profiles for reproduction for human observers, the best measurements are those that closely mimic what a human observer sees. So unless you are assuming all your viewers are wearing polarized glasses, it's hard to understand your enthusiasm for polarized measurements!"


I am not getting into a debate over this - I'm simply going to state that this is nonsense.

The use of a polariser when making profiles with matt paper significantly improves the shadow reads - it does so because the polariser removes light scatter. It has absolutely nothing to do with looking at images with polarised glasses and such a notion is laughable. If I show you two prints, one made with a polarised profile and one without you wouldn't know the difference other than the fact the polarised profile had much better shadow detail!

MHMG

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #61 on: July 12, 2017, 09:24:10 PM »


If I show you two prints, one made with a polarised profile and one without you wouldn't know the difference other than the fact the polarised profile had much better shadow detail!

Unless both image files used to make the two prints are carefully edited to bring out the desired amount of shadow detail using either type of profile. In which case, results will be entirely comparable. Been there, done that. The problem with the polarized data set is that it screws up the profile soft proofing accuracy significantly more than a non polarized set of data, so iterative printing is more likely to be required for other aspects of the image that have little to do with shadow retention when using a polarized data set to build the profile. I genuinely believe it's best to think of polarized data sets as special subsets of the general ICC profiling process, useful with some images for sure, just like choosing a particular rendering flavor, but not a universal win for all images in all situations.
« Last Edit: July 12, 2017, 09:27:35 PM by MHMG »
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GWGill

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #62 on: July 14, 2017, 10:25:35 PM »

The use of a polariser when making profiles with matt paper significantly improves the shadow reads - it does so because the polariser removes light scatter. It has absolutely nothing to do with looking at images with polarised glasses and such a notion is laughable. If I show you two prints, one made with a polarised profile and one without you wouldn't know the difference other than the fact the polarised profile had much better shadow detail!
Getting measurements that don't correspond to the visual characteristics is not profiling, and will just lead you astray in the long run.

It's possible you might get "better shadow detail" due to poor workflow :- i.e. if you are not properly linking the source and destination profiles using gamut mapping, but instead using a colorimetric (or poorly implemented perceptual) type intent, then yes the mismatch between the source black point (typically 0 for idealized source spaces like sRGB , AdobeRGB etc.) with the actual print black point will cause loss of shadows. So fudging the measurements to give the print an artificially good black point using polarized measurements will improve the situation, without actually tackling the underlying problem. The alternative is to not fool yourself - take measurements that actually correspond to the visual color, and use a good workflow that maps the luminances ranges of source and destination appropriately.
« Last Edit: July 14, 2017, 10:33:05 PM by GWGill »
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Doug Gray

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #63 on: October 16, 2017, 03:47:06 PM »

The use of a polariser when making profiles with matt paper significantly improves the shadow reads - it does so because the polariser removes light scatter. It has absolutely nothing to do with looking at images with polarised glasses and such a notion is laughable. If I show you two prints, one made with a polarised profile and one without you wouldn't know the difference other than the fact the polarised profile had much better shadow detail!

Actually, Josh, it does.  Reflected light from the rough matte, inked surfaces itself selectively reflects light depending on the direction of polarization of each photon.  Unpolarised light, when reflecting from a non-metallic surface with a different index of refraction from air will therefor reflect partially polarized light. M3 pre-polarizes light such that light that reflects off these surfaces towards the spectrophotometer is reduced. The effect is stronger with resin encapsulated pigment inks.

The black reduction effect is similar whether the polarizer is at the light source (M3) or at the viewer (polarized sunglasses).
« Last Edit: October 16, 2017, 03:52:29 PM by Doug Gray »
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Josh-H

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #64 on: October 16, 2017, 06:56:22 PM »

Actually, Josh, it does.  Reflected light from the rough matte, inked surfaces itself selectively reflects light depending on the direction of polarization of each photon.  Unpolarised light, when reflecting from a non-metallic surface with a different index of refraction from air will therefor reflect partially polarized light. M3 pre-polarizes light such that light that reflects off these surfaces towards the spectrophotometer is reduced. The effect is stronger with resin encapsulated pigment inks.

The black reduction effect is similar whether the polarizer is at the light source (M3) or at the viewer (polarized sunglasses).

Its the notion that you need polarised glasses to look at a print made with an M3 polarised profile that is laughable.

By that logic we should we look at photographs shot with a polariser with polarised glasses on!

Steve Upton

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #65 on: October 16, 2017, 07:22:58 PM »

Its the notion that you need polarised glasses to look at a print made with an M3 polarised profile that is laughable.

By that logic we should we look at photographs shot with a polariser with polarised glasses on!

I totally agree, it's a simplistic view of the problem and the use of M3 in profiling.

To continue the flawed logic, it would follow that any profiles built with UV filtering should only be viewed with UV filtered lighting - not a bad idea but also definitely not necessary.

We agree that the proofing intents of M3 profiles need to be improved and we're working on the process.

But, our belief is that M3 measurements, when used with certain media, creates significantly better rendered output and we have years of experience and happy customers to back that up.

An important question that has to be asked here is "Why do people presume that M0, M1 or M2 measurements are necessarily correct?". Our feeling is that the profiles built from those measurements also contain measurement flaws, especially when the media has an optically bumpy surface that reflects a significant amount of light off the surface. It's likely that the best set of measurements is some blend of M3 and others.

We're working the issue and will respond to the list when we know more.

In the meantime, try profiles built with M3 on different before condemning the practice. Mark S (to his credit) approached the idea with an open mind and came away preferring the M3 profiles.
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Doug Gray

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #66 on: October 16, 2017, 08:11:05 PM »

Its the notion that you need polarised glasses to look at a print made with an M3 polarised profile that is laughable.

Obviously. However, M3 can overstate DMax by discarding light that would normally reach a viewer of the print. Read again what I wrote. It is the reflections themselves that preferentially select and de-select polarized light reflected at an angle. The purpose of M3 is to discard that portion of light preferentially reflected to the viewer.  This creates a false DMax and should not be done. The spectro should be measuring exactly the same light levels that unpolarized light at 45 degrees produces.  Which is what M0-2 accomplish though with varying levels of uV to complicate life.
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Mark D Segal

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #67 on: October 16, 2017, 08:31:28 PM »

This creates a false DMax and should not be done.   

The DMax comes out differently in the M3 mode, but false relative to what? It may well be correct within the framework of its own technology - one can discuss that, but of what practical significance, the objective being to produce visibly better prints. So to say it should not be done kind of surprises me, when a number of us have seen that in certain contexts it produces visually superior results - in particular, Black shade appearance and shadow detail in the deep quartertones, and as Josh Holko demonstrated in his article, superior rendition of highlight tonality in very delicate photographs. The effect varies from substantial to insignificant depending on the photo and the paper. So I for one, based on what I've seen and experimented with, would not come down so categorically on it.
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Steve Upton

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #68 on: October 16, 2017, 08:48:54 PM »

Obviously. However, M3 can overstate DMax by discarding light that would normally reach a viewer of the print. Read again what I wrote. It is the reflections themselves that preferentially select and de-select polarized light reflected at an angle. The purpose of M3 is to discard that portion of light preferentially reflected to the viewer.  This creates a false DMax and should not be done. The spectro should be measuring exactly the same light levels that unpolarized light at 45 degrees produces.  Which is what M0-2 accomplish though with varying levels of uV to complicate life.

So what I hear you saying is that you choose to believe the non-M3 measurements as gospel.

Why?

With all the spectral reflections off the surface of glossy canvas, and the human tendency to slightly move one's head to minimize such reflections, yet the instruments inability to move from the 0/45 geometry, why are you thinking that the instrument is seeing things like you?

Again, I agree that the dMax returned from the profile is too dark, but I also counter that the dMax returned from non-M3 profiles is too light
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Doug Gray

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #69 on: October 16, 2017, 09:45:18 PM »

So what I hear you saying is that you choose to believe the non-M3 measurements as gospel.
Not at all. M0-2 have their own, very real limitations. M3 takes those limitations and alters the lighting by using polarized light that creates measurements that overstate both dynamic range and saturation. Unless, of course, the prints that use the profiles are illuminated from 45 degrees with polarizing filters. In that case they would be quite nice. And the dynamic range and colorimetry baked into the profile would be exactly right. The viewer wouldn't need polarizing glasses either. But illuminated "normally" they would exhibit poorer dynamic range and less saturation.
Quote

Why?

With all the spectral reflections off the surface of glossy canvas, and the human tendency to slightly move one's head to minimize such reflections, yet the instruments inability to move from the 0/45 geometry, why are you thinking that the instrument is seeing things like you?

Again, I agree that the dMax returned from the profile is too dark, but I also counter that the dMax returned from non-M3 profiles is too light

Yes, and that illustrates the limitations of both profile colorimetry and non-Lambertian prints. No profile can account for how people will view prints with specular effects from any glossy or luster type print. Which is why, when I discuss hard proof comparisons I take pains to point out that the illuminant should be at an angle (45 degrees preferably) and the ambient at much lower lux levels.

And, to your point, if properly made glossy type prints are displayed in a white room, evenly lit with diffuse lighting, they will appear to have much lower dynamic range as well as significantly reduced saturation.

Which is why prints of images that are in gamut on both matte and glossy paper, the glossy one will appear quite poorly in the white room environment while the matte prints made with m0-2 profiles will retain their proper appearance. Well, unless you put that matte prints behind standard glass.

But there is a case to be made for M3. If you display both matte prints and glossy type prints in the same white room and illuminate the prints only by ambient room light then matte prints made with M3 will better match glossy prints made with M2. The glossy prints will be effectively reduced in saturation and dynamic range to closer to that of the matte print.

« Last Edit: October 16, 2017, 10:10:23 PM by Doug Gray »
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Doug Gray

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #70 on: October 16, 2017, 09:52:50 PM »

The DMax comes out differently in the M3 mode, but false relative to what?

The Dmax is calculated directly from the spectrophotometer measurement of reflected light from the blackest patch. With M2 it is from reflected, randomly polarized light. When M3 is used it measures the fraction of reflected light that was polarized prior to reflection off the print. That will be significantly different on most matte paper surfaces and doesn't scale from the white reference white. Interestingly, it makes little difference on glossy papers. It is only accurate if the print is illuminated with polarized light in the same orientation. That's possible to do but can't say I've seen it done.

Additional info:
I don't want to overstate opposition to M3. There are situations where M3 can produce better visual results:
I do believe it's likely to make better profiles (in a visual sense) with canvas. Especially canvas with enough texture that significant specular reflections are present. Canvas presents a particularly difficult profile target in shadows because specular noise is unavoidable. One approach could be to create a larger set of duplicate patches. Scan them and reject the higher luminance outliers but this is tedious and time consuming. Normal use of a single, if large, patch set is not sufficient. One needs to create at least 3, and likely more duplicate prints of the patch set. Further, averaging is sub optimal. It's the outliers that need to be rejected. Just one remaining outlier can easily bump a patch luminance enough to create strange gradient bumps in prints using that profile.

Matte prints with M3 profiles are more problematic - see the discussion of how they are illuminated and the diffuse light (white room) ambient. I suspect M3 provides better results in the latter situation. Especially when comparing to glossy prints in the same setting. The colors should be more consistent between the two in that environment.

Also, while cross polarization is used for M3, it's not necessary for viewing prints from them to use polarized glasses since the light that is reflected is already highly polarized unless coming off things like metallic surfaces. Polarizing the illuminant accomplishes most of the specular attenuation.

Creating profiles using a light integrating sphere spectro would significantly decrease the DMax of glossy prints and drop the profile gamut considerably but it would provide a more colorimetrically accurate print when viewed in the diffuse white room I mentioned in earlier. It's also highly impractical, slow, and expensive.

The ICC recommends not using M3 and I believe I understand their reasoning. However, I suspect it is at least a reasonable choice on some substrates such as canvas.
« Last Edit: October 17, 2017, 12:48:16 AM by Doug Gray »
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Steve Upton

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #71 on: October 17, 2017, 12:53:53 AM »

But illuminated "normally" they would exhibit poorer dynamic range and less saturation.

But they don't. That's the point
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Doug Gray

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #72 on: October 17, 2017, 02:00:55 AM »

But they don't. That's the point

That's a question that can be resolved simply by analyzing the profiles with M2 and M3. Or colorimetric prints made with them viewed side by side. By definition, if the prints are illuminated in the same manner as profiles are made, that is from the side at 45 degrees, the reflectance of D50 from the prints will match the M2 profile uV effects aside. If the M3 profile differs then the illuminated print will not be the same using colorimetric intents (Perceptual and BPC realigns the tone curves but not the saturation reduction). How visible the difference is depends on the magnitude of the difference and the simplest approach is to compare the profiles.
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Alan Goldhammer

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #73 on: October 17, 2017, 08:01:36 AM »

I do not print on canvas but from my reading on LuLa, most printers coat canvas prints prior to framing.  Does the use of such coatings mean that the profile which is likely done on non-coated canvas targets is not as accurate?

Doug Gray is correct about viewing conditions.  I was down at my old office over the summer taking some light measurements of a series of prints that have been on display for 10 years.  I wanted to get some Lux measurements to get an idea about print stability.  I should have hung a color checker swatch that could be measured for fading but folks would probably have thought it was just some kind of op-art print.  As I reported at the time, the prints still look as good as when they were originally hung.  It's interesting that the display conditions, traditional office lighting, are illuminated at almost the 45 degree angle that Doug mentions. 
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Mark D Segal

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #74 on: October 17, 2017, 08:52:19 AM »

That's a question that can be resolved simply by analyzing the profiles with M2 and M3. Or colorimetric prints made with them viewed side by side. By definition, if the prints are illuminated in the same manner as profiles are made, that is from the side at 45 degrees, the reflectance of D50 from the prints will match the M2 profile uV effects aside. If the M3 profile differs then the illuminated print will not be the same using colorimetric intents (Perceptual and BPC realigns the tone curves but not the saturation reduction). How visible the difference is depends on the magnitude of the difference and the simplest approach is to compare the profiles.

In my experience comparing numbers and 2D/3D diagrams of many profiles with their corresponding prints, I've come to the realization that numbers and diagrams only take you so far, then you need to look at the prints. The numbers and diagrams are useful so I use them, but prints are the final product - the rest is inputs. The print producer needs to care about the inputs, but not be mesmerized by them. My normal viewing environment is roughly in the range of D50/45degree to the light source, but not exactly, so my comparative vantage point is within a range of near consistency, and I've seen disconnects between what one may infer from data and what one sees on paper - sometimes rather glaring ones - so one needs to have a balanced approach to reliance on inputs and product in deciding what works best for the print of a photograph (not a patch chart).
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Mark D Segal (formerly MarkDS)
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Doug Gray

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Re: Red River Palo Duro Etching matte paper on Epson 3880 - first look
« Reply #75 on: October 17, 2017, 06:43:40 PM »

In my experience comparing numbers and 2D/3D diagrams of many profiles with their corresponding prints, I've come to the realization that numbers and diagrams only take you so far, then you need to look at the prints. The numbers and diagrams are useful so I use them, but prints are the final product - the rest is inputs. The print producer needs to care about the inputs, but not be mesmerized by them. My normal viewing environment is roughly in the range of D50/45degree to the light source, but not exactly, so my comparative vantage point is within a range of near consistency, and I've seen disconnects between what one may infer from data and what one sees on paper - sometimes rather glaring ones - so one needs to have a balanced approach to reliance on inputs and product in deciding what works best for the print of a photograph (not a patch chart).

First, a comment about 2D and 3D gamut plots. To me they are eye candy and rarely useful. They tell nothing about Perceptual Intent, and nothing about how colors that are outside the gamut are mapped to printable colors. They are useful largely for just determining whether a color is printable and while of value for repro work it isn't useful for most photographic prints because even with Relative Colorimetric, one has to convert the color values to the scaled L* values actually printed. So, mostly eye candy. But I do use the 2d gamut viewer in PM5's profile editor (or more likely a Matlab routine) when a color I'm trying to print may be marginal. Usually I'm doing repro in those cases.

But as for instruments, I too have had unexpected "surprises."  I love them! In large part because I come to printing from an engineering background where the most interesting questions, and often opportunities, show up when a discrepancy occurs between something instruments say should happen and what actually happens. That means the instrument readings are outside operating parameters, a mistake was made, or my understanding is wrong. Since it's usually the latter, especially doing something new, I become obsessive about understanding the discrepancy then verifying it.

Also, my earliest printing work was creating analog charts with superimposed sine waves to measure imager registration plane error to sub micron accuracy where printing controlled linearity was critical.

So whenever I get results that apparently differ from what instrumentation says, I dig into it until I understand why.

As an aside, My experience with canvas is limited. When I tried, years ago, to make profiles - and canvas prints - for some artist friends, the results were not pleasing. Especially in shadows. I was getting erratic results in the darker patches and wound up using Epson's canned canvas profiles. That has been the only media I have wound up having to use canned profiles. And they worked quite well. I suspect if I had M3 it would have produced better visual results even if at the cost of colorimetric accuracy. However, colorimetric accuracy is of value mostly in repro and printing proofs. Using BPC and/or Perceptual intent already discards colorimetric accuracy. Obviously not a big problem in the photographic world since Lightroom forces BPC.

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