Non-neutral grays with R1800?

[poco]

Yesterday I was playing with my brand, spanking new R1800 when I came across a real problem. I was printing a shot with uniform overcast sky and kept getting a noticable magenta cast at one end where the sky was slightly darker, though still gray. I tinkered with the file up and down and finally, in an act of total desparation, desaturated the sky entirely and STILL got the magenta cast. I rotated the shot so it printed the other way around and that didn't solve the problem either-- that end of the sky where it got darker, drifted towards magenta as well. So what's up with that? What could I be doing wrong? Shouldn't all values with equal RGB values, though different intensities print neutral? If this is a printer "feature," it's going back on Monday.

[PViapiano]

Because color printers use all the ink colors even when printing B&W photos, a color cast is inevitable. It even looks different under different kinds of light. This is called metamerism, and it's always been a problem esp with dye printers like the 1800.

Epson's newer R2400 and 3800 pigment printers have a feature called ABW, which allows you to print a neutral print and/or tone it the way you want, if so desired. Custom ink sets from people like Jon Cone can transform a printer like yours to a B&W only printer with supposedly great results.

I've been printing with an older Canon S9000 dye printer and have been finding the same results as you have. I find that I can alleviate it a little bit by printing a Grayscale image in Photoshop, set for Same As Source in the Print with Preview dialog box. Not perfect but better...

Another option is to download the QuadTone RIP demo and mess with that until you get the result you'd like...

There's no easy way, besides buying a new printer...in your case, the R2400 may serve you best.

[Ron Marshall]

My solution was an refurb Epson 2200 and monochrome inks. I use the NK7 inks from Inkjetmall. They are seven serial dilutions of black ink so they are always neutral.

I also use the Quadtone RIP. Even with colured inks I have read that it improves the neutrality of grays. Good luck!

http://shopping.netsuite.com/s.nl/c.362672/sc.15/category.1258/.f

[Helen Bach]

Poco,

I got the impression that you are talking about neutral parts of a colour image. If so, it is a profiling problem. How are you applying your profiles? Which paper and which profile are you using?

Best,
Helen

[Ted Harris]

PV, the R1800 is a pigmented ink printer .... it is the wide versionof the R800. I agree that Quadtone RIP is likely the easiest answer. Back to poco ... is the print you are talking about B&W or color, that isn't clear from your post and all the answers so far, except Helen's (including my comments above) assume B&W.

If we are talking B&W another solutionis to use quadtone or duotone rinting whcih you can access from within PS (see Ken Lee's quadtones on his web page for example). If we are talking color then you may need to work more with your color mixing ... why not post a pjeg here of the print in question ... would be very helpful.

[dwhistance]

If you are trying to print B&W with the R1800 and the original Epson inks then you will struggle to get a totally neutral print due to the lack of grey's available in that printer. Instead of adding a "light black" as they did for the 2200 Epson tried to enhance the colour gamut by adding the red and blue inks. I suspect that the best solution available without changing inks is to use the Quadtone RIP (QTR) as suggested above. You will find some specific profiles for the R1800 on the QTR Yahoo forum: http://tech.groups.yahoo.com/group/QuadtoneRIP/ in ther files area.

If having tried this you are still finding that greys aren't neutral then I can recommend the Cone Piezography NK7 inks in this printer.

David Whistance

[poco]

Sorry, I was indeed talking about printing a color image. All the profile stuff still has me confused (slowly learning) but the printer profile is the same as the input file, Adobe RGB, and using the canned profile that came with the printer gets me results which are very close to accurate, so I don't think I'm using the wrong settings. Except for this neutral gray issue, I'm satisfied with the results.

Thanks...

[archivue]

if you are using profile, and you are printing from photoshop, make shure that :
you choose the printer profile "R1800+paper type"
you select : let photoshop control the color
and, in the epson driver : color : no calibration

[Helen Bach]

"Sorry, I was indeed talking about printing a color image."

That's what it sounded like to me - there are three good clues in your original post.

If you have followed the procedure that archivue describes* and still have the problem, would you like me to make you a custom profile to see if that's any better, or would you like me to print your image on my R800 to compare? Which paper and which printer profile are you using now? What image software are you printing from? The more you tell us about what you are doing, the easier it is to help.

* Just to clarify "in the epson driver : color : no calibration": In the Epson driver under Color Management select the ICM button, then under ICC/ICM Profile select the Off (No Color Adjustment) button.

Best,
Helen

[poco]

Helen,

Your generosity, knowledge, and unfailing good humor bowl me over time everytime I see your contributions here or on APUG. You're a gem. But before I put you out further, let me give as much info as possible to see if you or anyone else can spot where I'm screwing up:

I'm printing out of photoshop (though an ancient version), and when I click on File/Print/setup, I have Adobe RGB and Perceptual selected as Print Space Profile and Intent, and under Properties, I have Premium Glossy paper selected (what I'm using) and under Color Management, have ICM selected. Under ICM Mode, I have Driver ICM (basic) selected (I've tried all the other ICM options and they're no better and if I click on No Color Mangement, the colors really go batty).

The setup noted above gets me very close to proper prints except that in general it yields ever so slightly exagerated subtle color shifts and, on the other hand, pretty notable muting of strong colors. It's like if the A and B curves where steepend in the middle of a LAB curve and the extremes flattened. I could learn to compensate for that in file prep, but the fact that a totally desaturated sky results in subtle hue shifts makes me think there's something seriously off with either my setup or printer.

Thanks...

[Daniel Geiger]

Is your monitor calibrated and profiled? If you monitor is off, then it really becomes a guessing game of how to adjust the file. I use a Monaco Optix spider to do that job. Also in PS, use the "proof color" setting to get a better preview of what the image could look like, an check the "out of gamut" option as well (although desaturation should alleviate any out of gamut problems, but good to check anyway). Last but not least, the differences in color representation (additive vs. subtractive) will lead to some inconsistencies, however slight.

When I got into color printing also with an Epson R1800, I read Real World Colormanagement from Peach Pit Press, and also have the Focal Press Color Management for Photographers volume. It helped me a lot to get through all the new terminology.

I did notice when I printed some pure black & white images, that depending on ink-levels in the various colors, slight hues are introduced. Basically what you would see in warm-tone vs. cool-tone papers. Nothing I worry about, but when I compared some prints from different batches, it is quite noticeable.

Best wishes

[Bruce Watson]

Shouldn't all values with equal RGB values, though different intensities print neutral? If this is a printer "feature," it's going back on Monday.

Should they? You can make the case that they should. Will they? Often not. And yes, this is a feature of trying to print B&W images with color inks. You are trying to get the printer, driver, and inks to do something they aren't designed to do, and certainly not optimized to do, so your results shouldn't be surprising.

Many of us, when faced with similar needs, use two different printers. One for color, and one for B&W. The B&W printer gets grayscale inks designed for the duty (think MIS, Cone), and many people are using QTR to drive the printer as it is also optimized for B&W printing.

Now if you want to have more fun, take those color ink B&W images around and look at them under different lighting. It's called metamerism...

[poco]

"You are trying to get the printer, driver, and inks to do something they aren't designed to do"

While I was late in clarifying it, all I'm trying to do is print a COLOR photograph containing a neutral gray sky without parts of that sky taking on a magenta cast. Surely a color printer, using color inks, should be able to do that.

[Bruce Watson]

"You are trying to get the printer, driver, and inks to do something they aren't designed to do"

While I was late in clarifying it, all I'm trying to do is print a COLOR photograph containing a neutral gray sky without parts of that sky taking on a magenta cast. Surely a color printer, using color inks, should be able to do that.

The Epson printers using gray inks (like the significantly more expensive 2400) will do a better job of this than a printer without a gray ink like the 1800. Good neutrals are hard to create using the inks that the 1800 has available.

[Helen Bach]

Poco,

I printed this picture of the interior of Peter Eisenmann's House VI on my R800 as a test. I used the canned profile for Epson Premium Glossy Photo, with the 'Best Photo' setting - which is what the profile was written for (SPR800 PremGlossy BstPhoto.icc). It wasn't perfect, but it was fairly close. I'd be happy to post it to you tomorrow morning for comparison if you PM me with your address.

http://gallery.photo.net/photo/5677598-lg.jpg

Which version of Photoshop are you using?

Bruce,

"Now if you want to have more fun, take those color ink B&W images around and look at them under different lighting. It's called metamerism..."

If that property, which used to be called colour constancy or inconstancy, is now called metamerism what do we now call the property that used to be called metamerism? This is a genuine question, not a snide remark - I realise that the meaning that you give to metamerism is widespread in this fresh-fangled digital printing business.

Best,
Helen

[poco]

Helen,

I'm in the dark ages with Photoshop 6.

PM sent, and nice subtle shot.


-Michael

[Ken Lee]

As Daniel Geiger says, unless you are using a completely calibrated and profiled workflow, it's a guessing game - and that's putting it politely. I'd call it "maddening" instead.

You can get a custom profile from inkjetart.com (http://www.inkjetart.com/custom/) for much less than the cost of the paper you have/will already wasted. The profiles you get from Epson are OK, but keep in mind that grey (http://www.kenleegallery.com/html/tech/calibrate.html) is the hardest tone to reproduce.

[Helen Bach]

With printers like the R800 and 2100/2200 it can take some effort to improve on the Epson profiles, particularly with the rendering of greys, if you are using the correct paper and ink combination and the right media and resolution settings. Before settling on Profilemaker 5 I tried a few well-known profiling services and then the PrintFix Pro, and often found that they couldn't beat the Epson profiles for neutrality.

Nobody is suggesting that perfection is possible, but acceptable deviation might be within reach. Of course, if you know you are going to deviate, al least you should choose the side to wander off to.

Photoshop 6 should be OK for colour management as far as I know - I still use it on one of my computers and it happens to be the general purpose one that is connected to the R800. I used PS6 for the test print I'm about to send you, so our software, printer, paper and ink should match. Well, apart from the old R800 / new R1800 difference.

Because you really have to micromanage some of those easily-distracted Epson consumer printers into doing a proper job, I'd suggest using a larger number of patches for profiling than would be adequate for better-behaved (more expensive) printers. There's a four-page target with 1452 patches that has a good set of neutral patches (those all have R = G = B and you don't need a profiled monitor to tell you that that should print neutral) that I could send you if you wished to try a custom profile. First let's see how your printer compares with my old R800.

Best,
Helen

[Bruce Watson]

If that property, which used to be called colour constancy or inconstancy, is now called metamerism what do we now call the property that used to be called metamerism? This is a genuine question, not a snide remark - I realise that the meaning that you give to metamerism is widespread in this fresh-fangled digital printing business.

I was indicating a condition called "illuminant metamerism" in which a given sample will show variance in color depending on the spectral power distribution of the light source.

What I remember about "color constancy" is that the term is used mostly in discussions of how the human eye/brain system perceives color, and describes how the eye/brain system keeps perceived color constant in changing lighting conditions. For example, a red truck driving from sunlight into shadow continues to register as the same red even though the actual reflected spectrum has changed.

[Helen Bach]

I was indicating a condition called "illuminant metamerism" in which a given sample will show variance in color depending on the spectral power distribution of the light source.

What I remember about "color constancy" is that the term is used mostly in discussions of how the human eye/brain system perceives color, and describes how the eye/brain system keeps perceived color constant in changing lighting conditions. For example, a red truck driving from sunlight into shadow continues to register as the same red even though the actual reflected spectrum has changed.

That's how I understand colour constancy as well: the degree to which a colour appears to be the same under different lighting conditions. If it doesn't look the same, it exhibits colour inconstancy. So if something looks neutral in one type of illumination and green in another, it can be said to exhibit colour inconstancy.

My understanding of metamerism is that defined by the CIE in the CIE International Lighting Vocabulary: spectrally different colour stimuli that have the same tristimulus values. The corresponding property is called metamerism. (ie two different materials that appear to be the same colour although they don't have the same spectral characteristics. The entire field of colour reproduction depends on metamerism.) For example a painted wall and a photograph of the wall that has been colour matched to the wall can be said to be an example of metamerism. Under the CIE definition, the greater the degree of metamerism the more they look alike under different illuminants. What you call metamerism, others would call metameric failure.

Best,
Helen

[Bruce Watson]

That's how I understand colour constancy as well: the degree to which a colour appears to be the same under different lighting conditions. If it doesn't look the same, it exhibits colour inconstancy. So if something looks neutral in one type of illumination and green in another, it can be said to exhibit colour inconstancy.

Arguing definitions can be fun, but I doubt it's helping the OP. Still, since we are here...

I don't think we are in agreement here. I said that I recall that color constancy is a property of eye/brain perception. You are saying that it's a property of the object. They aren't at all the same thing.

Color constancy is the property of color perception that keeps the world from looking like a kaleidoscope. Without it, we would see a landscape of constantly changing colors. Every changing lighting condition would result in color shifts. Stepping out from the shadow of a building into sunlight would be a disorienting experience. One of the theories about how the eye/brain system accomplishes color constancy postulates the existence of a "black channel" that's actually somewhat separate from the rest of the visual processing wetware. IOW, the eye/brain system does not see in RGB, but in RGBK. Interesting ongoing research.


My understanding of metamerism is that defined by the CIE in the CIE International Lighting Vocabulary: spectrally different colour stimuli that have the same tristimulus values. The corresponding property is called metamerism. (ie two different materials that appear to be the same colour although they don't have the same spectral characteristics. The entire field of colour reproduction depends on metamerism.) For example a painted wall and a photograph of the wall that has been colour matched to the wall can be said to be an example of metamerism. Under the CIE definition, the greater the degree of metamerism the more they look alike under different illuminants. What you call metamerism, others would call metameric failure.

One of the joys of language, particularly English, is that individual terms often come to have many meanings. This is particularly true of languages used over wide geographic areas.

In this case, I am using the term as you say. The definition I was taught for metamerism is that it is the property of an object to change color under different lighting -- the object is said to exhibit metamerism. For better or worse, that's what I was taught.

I have a failed ink experiment that provides a neutral B&W print only under 3200K halogen lighting. It's been years since I looked at it, but IIRC, with a 5000K fluorescent it turns green, while in direct sunlight it turns a striking blue. Metamerism or metameric failure, it's still bad ink, and an unacceptable print.

[Helen Bach]

"The definition I was taught for metamerism is that it is the property of an object to change color under different lighting..."

Now that is what I would call colour inconstancy, definitely not what I would call metamerism.

The CIE definition of metamerism is that metamers look the same, not different. You appear to be using it to denote difference. Metamerism is not a property of one object, it is a property of at least two objects, according to the CIE. In this case one of the objects seems to be a hypothetical, perfectly neutral, object.

Well, I knew that there were two different and opposite meanings in general use for metamerism. Now I have discovered that there are two different meanings for colour constancy as well. It's a good job that this is an inconsequential issue in the grand scheme of things, but it's probably worth bearing in mind that the two terms appear to have no internationally accepted consistent meaning.

Best,
Helen