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Author Topic: Using the HP Z3200 spectrophotometer to generate profiles for other printers  (Read 10312 times)

Ernst Dinkla

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Good posts never die.  As doesn't my Z3200. 

2. I've never understood why only RGB (and not CMYK profiles) are used to profile printers that have both sets of inks.  If someone could lift this burden, I'd be grateful.

Thanks

With the RGB inks in the 12 ink set of a Z3xxx you can not make a full color print. Papers can not reflect enough light for additive RGB mixing and that is the only way RGB colors can create full color images. That in contrast with light emitting/transmitting displays where enough light is emitted through the RGB pixels. It would be interesting though whether the RGB inks of the Zxxx ink set could be addressed independently (with a very flexible RIP) and print on a transparent foil in additive dithering and displayed with light thrown through it. The inks are actually red, mint green and violet so not ideal either for that task. "interesting" as in having too much time and experimenting as an artist. Like I have done ages ago with RGB inks silkscreen printed in a line raster on foil.

The RGB profiling is aimed at OEM drivers that have their color management at the RGB side of the conversion from RGB images to CMYKetc ink sets, so called RGB-device printer color management. The CMYK profiling is aimed at RIPs that have their color management at the other side of the RGB>CMYK (and CMYK space>Printer CMYK) conversion or maybe better described; have their color management on the conversion itself.

The RGB inks in the Zxxx printers have a different task; they replace mixes of the LcMY inks at certain color hue angles when the required saturation gets too high for resp MY, LcY, MLc ink mixes. So less of the LcMY inks are used there and more of the RGB inks. It is comparable to the use of the grey inks where the low saturation mixes are gradually replaced by the grey inks till neutral only contains grey/black inks. At that side to create more consistent neutrality.


Met vriendelijke groet, Ernst

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« Last Edit: June 26, 2017, 06:21:23 am by Ernst Dinkla »
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Geraldo Garcia

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Good posts never die.  As doesn't my Z3200. 
Thanks!  ;D

Quote
1. I am unsure I understand Geraldo's quote further below (I am certain it's my ignorance).  Does this mean the Argyll profile is useful only in printing/converting using relative colorimetric?  Should I create both ICC sets and use one for strictly relative colorimetric work and another for conversions to perceptual?  As background, I soft proof ProPhoto RGB TIFFs using relative colorimetric in Photoshop, but render them usually out of PS or LR in perceptual, and sometimes using HP's 16 bit web-based RIP.

That statement/behavior from Argyll almost fried my brain too. The thing is, their profiles work perfectly for RelCol conversions. For perceptual intent you should specify the input colorspace during the profile creation. That means you will have a profile that can only (properly) render images from that colorspace, lets say, AdobeRGB. Of course you can create several profiles from the same data file, one for AdobeRGB, one for sRGB, one ProPhoto... and choose the right one when you need.

Now, I can't understand why you softproof using RelCol and prints using Perceptual. You should use the same!

Regards.
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Brad P

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Thanks Geraldo.  I think I got it.  I always render my files now out of Phocus to ProPhoto RGB, then take them into LR, PS and other ProPhoto compatible plugins in my workflow.  And I pretty much always print in relative, so unless you or someone corrects me, I'll follow method 2 in your first series of posts. 

Proofing in RelCol and printing in perceptual is a small part of a relatively new larger proofing process for me.  Since you asked, I use ColorThink to identify out of gamut colors of an image I'm about to print. Then I manipulate those specific OOG colors using PS hue/saturation layers with luminosity curve masks to push the offending colors into print gamut, checking on the results of that against the soft proofing gamut warnings in PS.  Because PS's gamut warnings do not identify all OOG colors and round tripping to CT is a pain, when I get most or all of the PS gamut warnings to disappear, I proof print in Relcol first to see if I care about the differences, then aim to final print in perceptual because at least in theory that preserves at-the-margin hidden color detail.   Having typed that out and reflecting on my experience so far, the RelCol print is the least important part, and I might just as well rely on the perceptual rendering proofs since I'm getting pretty darn close using PS gamut warnings anyway.  Will save paper too.   ;)   

Thanks to Ernst too!
« Last Edit: June 26, 2017, 06:08:44 pm by Brad P »
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Brad P

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I now have everything uploaded and have a couple of comments.

Importantly for those following this thread, the original intent of this thread is to use the Z3200's internal spectrophotometer to create profiles for other printers.  In contrast, I like some other followers am attempting to create a better profile for my Z3200ps (version B) using an expanded color profile described in the first few posts.  This is a larger gamut profile that natively prints and scans by the Z3200, but does not appear at least to me to natively process and upload. Manual tweaks like this seem capable to improve the Z3200's printing gamut a bit.   

1. Looking with ColorThink my "before" printing gamut (created with the Z3200's canned hardware and programming) and the "after" gamut (created with the much larger sample, run through Argyll), I'm just barely over the fence that rendering of the larger profile is worth the time, money and effort.  It seems for now to be.  The new gamut appears well matched to the old and maybe up to 3-5% bigger overall.  Worthwhile to explore. 

2. I ended up following Geraldo's original instructions rather than a few well intended offshoots here and elsewhere.  Very well done Geraldo.  For Mac users, you may need to include root directories in the terminal program names and file names as I did.

3. I am having soft proofing issues with the new gamut. All appears normal in Photoshop, but Lightroom (which I usually print from) now shows the printer gamut blown out. Probably user error, possibly something else. 

4. Simultaneously I am working with CHROMiX on a custom built profile for the same paper I am profiling here. The first round of that separate process is encouraging in that the printer gamut appears to be much larger (Maybe 15% in ColorThink, smaller in places too), but appears from tonight more difficult to install. 

We'll see how it goes.

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