CHROMiX

Eye One Strip Reading

What detailed documentation of Eye One capabilities can I get?

For example I’d like to know what measurement mode “correlate” with corr_colorants_count “2” does with all of those extra blue and green patches?

Can I make my own test charts that don’t have all the extra blue and green patches? Bill Atkinson’s targets and reference files for the Eye One don’t operate in that same mode. Upside looks to be more real color patches being measured. What’s the downside?

The green & blue patches are how the i1 & Gretag/X-Rite profiling & measurement apps know which row the user is scanning & if scanning from left-right or vice-versa for programs that allow scanning from both directions.

I had immense difficulties trying to use Bill’s profile targets when I tried to use his original targets & reference files. I would sometimes have to rescan a row up to 5 or more times before getting a successful scan & it would often take me about an hour or so to scan a single A3 page.

When I used his reference files & created new targets using GretagMacbeth Measuretool 5 I would have absolutely no problems whatsoever & can scan in both directions & SO much faster than I could using Bill’s original versions. With the Measuretool reconfigured versions of Bill’s targets I can scan an A3 page in about 15-20mins & that’s using an i1 that’s about 4 or 5 years old (rev A).

As a side note, I believe the Measuretool created targets are far better than Bill’s in every way. Georgio Truchio (sorry if I messed up your name Georgio) came to the same conclusion about Measuretool vs MonacoProfiler targets, showing in easy to understand graphs how the Measuretool targets have many more patches sampling the neutral, near-neutral & pastel/low saturation/low chroma areas of the printer’s gamut. If you have a look at Bill’s targets in a 3D graph in ColorThink, you’ll notice there are very few neutral, near-neutral & pastel/low saturation/low chroma patches. When inspecting the Measuretool targets (original Measuretool targets created in Measuretool using the target creator, not just Bill’s targets rebuilt using Measuretool) it is immediately obvious how many more neutral, near-neutral & pastel/low saturation/low chroma patches there are. There is a huge column of dots going almost inline with L* axis & a bunch more around the L* axis, which are completely absent in Bill’s targets. Even when looking at his targets in photoshop, you can see there are very few neutral & low saturation patches. This can obviously only be a good thing as it is sampling a far greater range of the printer’s gamut.

As for your question about measuring more “real colours” when using your own targets, there is absolutely no advantage (unless you count using less paper/ink) because whatever number is in the target name, as in TC918, TC1728, TCwhatever, the number indicates the actual colour patches used in creating the profile. The green & blue place-markers are not counted & this can be verified by multiplying the rows by columns & subtracting the green & blue patches & also the empty white patches at the start.

If you’d like me to create some targets for you just PM me with your specifications & I can email them to you. They can be made for any size paper that will fit in the i1 scanning backboard ruler (width that is, length is just about unlimited) & can be up to around 11000 patches max I think.

Hope that helps.

Thank you for the excellent response. I see exactly what you mean about Bill’s targets versus Measuretool targets with their emphasis on different areas of the gamut. Very interesting to me.

I’ve been an ImagePrint user on 9600 and 9800, but now, with my new 9900, I’m using PM5, Eye One, and ColorThink to build and analyze my own profiles.

Currently I’m trying to define a methodology for picking the best 9900 native Epson driver Media Type and Color Density settings for each of my production papers in preparation for building final profiles.

I’m closely examining what happens as I increase Color Density in the Epson Driver: line pair resolution, ink mottling, bleeding, running, paper cockling, black point shift, shadow compression, linearity, chroma gain in some colors, chroma loss in some colors… other effects? I’m trying to understand the tradeoffs so I’ll know WHY to choose one setting over another.

I’m also wanting to figure out the best target for final profiling. Tested 283 versus 918 and saw major quality difference on printed test images. Built my own 2625 using Measuretool and it was obviously better than 918. Latest effort is 3875. That’s a LOT of strip reading! – hence my desire to know the purpose of all those extra green/blue patches. I’d like to understand the potential point of diminishing returns for increasing the number of patches (e.g. for those with a critical eye and real world experience, would 5000 patches yield any real visual print improvement over 3875)?

As I increase the Color Density setting, chroma improves (to a point of diminishing return) but I think linearity suffers (though I’m not sure); do additional patches help Profilemaker mitigate the negative linearity effects of increased density? What’s the best way to quantify and compare linearity? I’ve built a 33 patch linearity chart (0, 8, 16 … 248, 255), but how to interpret results and how much does it matter?

The printer profiling process is new to me, so I’m on a steep learning curve – and at this point a bit obsessed with gaining an understanding.

Thanks for your help.

  • Brad

I can see both sides of this issue - the Atkinson and the ProfileMaker point of view. The Atkinson targets are probably best intended for building profiles using Monaco Profiler, and I don’t know of anyone who makes profiles using a 1-page Atkinson target. Usually it is the 1728 patch target that is used as a minimum. Naturally, this has more patches in all areas of the spectrum, not just the neutrals - but it includes more patches in the neutrals - so it should do a good job with neutrals even in the ProfileMaker software. The ProfileMaker software tends to “need” these near neutral patches in order to get accurate grays, while it is said that Monaco Profiler does a good job with neutrals without needing so many patches. So it rather depends on your perspective. In general, it’s best to stick with the target generation method that is intended for your particular software.

Brad, you’re already delving in deeper than many dare to tread! More ink will tend to get you more saturation as you are seeing, but when it starts to puddle up or take too long to dry, you’ve gone too far. We find it helpful to print a “visual” profiling target (instead of a randomized target) so we can see the gradation of colors and make a visual assessment of linearity and issues with dark colors & shadows. 2000 patches seems to be a rough working limit for quality profiles. You might get better results with more patches but in many cases (not all) it’s not going to be significant in the final results of your printed work.

Another point to consider is smoothness of the profile. More patches might make a more “accurate” profile, but will probably give you a less “smooth” profile. We want colors in an image to blend smoothly throughout a gradient, from one subtle color to another.

The ColorThink Pro grapher is a great tool for checking linearity. There’s even a workflow in the ColorSmarts Guide to evaluate a devices linearity:
colorwiki.com/wiki/Evaluate_Device_Linearity

The ends of the spider graph start to curve around into different hues and even reverse in chroma when you have too much ink on a page.

I went through almost the exact same process & steps (it’s kinda scary how identical everything you’ve mentioned is to the things I was trying - almost seems like you must have some sort of parallel universe brain scanner because you might as well have been writing from my memories. Seriously, near identical thoughts, trials, things that are holding you up/trying to figure out) a couple of years ago when I had a 3800.

In the end I found the greatest problem I had was not being able to limit the individual ink/channels as I too was using the Epson driver, couldn’t afford a rip at the time - still can’t. I found that as I would increase the ink density, 1 or 2 inks would be near perfect while others would obviously be over- or under-inking & because of the lack of granular control over what the printer is doing & how it’s laying down the ink, I couldn’t really go much further.

What I found after literally months of tests & measurements & Colorthink analyisis & PatchTool analysis & of course, prints of actual real world images (not just PDI test print images, etc) was that no matter how many test one runs or charts are measured, with the Epson driver & having only a single ink density control to really play with, other than paper types & platen gap - and platen doesn’t affect colour at all I found, just head strikes & perhaps some might say detail - it pretty much does come down to a visual inspection as Pat mentioned. I was constantly on the lookout for the graininess & break-up that occurs when there is too much ink & trying to keep that to a minimum while still having the maximum ink density setting I deemed satisfactory.

And after all those months of testing & way too many late nights, I found that I did actually prefer MonacoProfiler profiles over the PMP5 profiles. I only print RGB images, never CMYK & never proofing another device. I found that profiles from both apps would give excellent soft proof on my Eizo CG242W but I preferred the printed output from MonacoProfiler.

That made the descision about target patch numbers irrelevant as 1728 is the maximum number of patches that can be used for creating an RGB profile with MonacoProfiler 4.8. And they were definitely the equal or better than profiles created with up to ~4200 patches (that was the most my arm could take, scanning using the i1 white backboard ruler device).

As Pat again pointed out, these days it isn’t really necessary to have so many patches in our targets because the printers are so much better behaved (read linear) that around 1500-2000 was the maximum I ever needed. With the 3800, more patches didn’t seem to have any effect, good or bad. I’d have to guess that the 9900 would be even better in regard to linearity & predicatbility than 3800/3880.

Now that I have a 3880 for the past (can’t remember how long it’s been out, got it few days after release) however long it’s been, I sorted out the ink density by going for Dmax & smooth patches in my printed targets & smooth gradients or solid colour areas in images. The only problem now is that with the controls inside MonacoProfiler, allowing control over the amount of gamut compression for both lightness & chroma I’m almost creating new profiles on a per-image basis. Not quite, but it seems that way at times.

I guess it all depends what one is doing with their printed output. I wasn’t proofing or doing commercial work so deltaE numbers really only mattered to my ego. Much more important is how the final print appeared visually because that’s all that matters once it’s in a gallery or on someone’s wall.

Thanks Patrick and Aaron. Having reached the same conclusion as both of you, I’d already built my own “visual” chart with groupings of pure color patches in a rainbow line followed by patches stepping down from quarter tones for each color. This lets me clearly see, compare side-by-side, AND measure the effects of increased density.

Quantifying device linearity is still confusing to me. The L in Lab or LCH is human perceptual linear, not physical reflectance linear, correct? (i.e. 18% physical reflectance gray is human perceptual luminosity of 50%). When we talk about device linearity, are we referring to physical reflectance? Is it a different metric if we’re talking about color channels versus grayscale? Am I losing my mind?

I had tried the Colorsmarts device linearity evaluation early on, but wasn’t sure how to interpret it. Also, I was analyzing simple step charts, not yet measuring full targets and building profiles. Guess I was yearning for columns of numbers and quantitative comparisons rather than graphical representations, but maybe that was the wrong approach.

Aaron, I agree with you about basic limitations of having a single setting for density control and also your statements about effects of platen gaps. An FYI… for the 2880/MK media type settings on 9900, all the basic color characteristics are nearly identical with the exception of Ultrasmooth Fine Art, which has hyper greens and dead blues compared to the others. Haven’t tested below 2880 or PK yet.

The patch count information you both provided helps me immensely. The idea of the smoothness of the profile hadn’t occurred to me. I knew there must be a point of diminishing return on patch count, but hadn’t thought that, given the same inking, more patches versus fewer could ever result in a profile that produces a less desirable print. I’m very sensitive to the smoothness of gradients. The test images I’ve collected over the years include a lot of natural gradients, and I’ll be watching those closely as I analyze my profiles.

Now that I have access to different gamut mapping strategies (PM5 classic, chroma plus, colorful), I see the temptation to experiment with different profiles on an image by image basis, yet that’s exactly the image specific complexity I’d hoped to avoid by using profiles in the first place! Yikes. But, hopefully, as I gain an understanding of what’s going on with the various mappings – and any other options that come along, like the Monaco lightness and chroma gamut compression controls Aaron mentions – it will all work to my advantage.

Thanks.

  • Brad