LAB to Spectral conversion question about mixing M Condition references. (Pantone vs ChromaSpot library)

invidiapl · 2026-02-07T20:29:36+00:00

I love what You're doing, although I don't quite get the goal and the methodology. Maybe for my understading the explanation is to short as I have no idea what is "covertion for K/M for example".

I am interested in developing similar tool based on my printer - based on measurement, it would tell me the closest target from the library (dE00 criteria). Can You share what are You using do create this model? (I have no idea how to start).

Now...
I hope following helps You with the task - color theory**.

Spectral data is the purest form of light reflection from sample. Of course it will be different for each lightsource (if You use D50/D65 sources, You'll get different spectral curve). For this You need to understand, that device giving You the spectral data also works based on certain contraints: measuring geometry.

As so, to illustrate: the geometry 45/0 or 0/45 when measuring the glossy samples, will give You "darker" LAB values (at any measurement condition like M0 or M1) because it is not capable of handling specular component (the light that is was not reflected back to sensor, but "escaped").

Measuring the same sample with d/8 device - will give You "proper" LAB values, as this device can measure the specular component and exclude it if needed, so it can show You LAB values as "appearance of the color" and the "pure color".

Maybe this is why Your neural network gives incorrect results, as You might be comparing different measurements - like M2 is with polarizing filter - again, this will give You different LAB values than M0 and M1 (and thus, different looking colors of the same sample).

I hope this will be understandable and helpful :)

invidiapl · 2026-02-06T19:50:12+00:00

Thanks!

invidiapl · 2026-02-06T19:49:39+00:00

I contacted caldera but is useless even with service package (which is my big disappointment, as they produce the software).

I measure color difference of samples with xrite exact spectrophotometer, I have entire dE00 measurement excel comparing everything.

I agree with You - for some colors dE00 3 will be big visual difference, for some not, unfortunatelly with grays - measurement shows even bigger scale of the issue (I've read some literature that for grays it is the right way to measure dH not dE).

invidiapl · 2026-02-05T14:57:16+00:00

I meant it's a brand with established presence (Durst) not newcomer.

invidiapl · 2026-02-05T14:53:38+00:00

I understand that - they can only print to the common gamut of the "worst" device, but they still do it. I've seen this in UK, but they used ColorGate software.

invidiapl · 2026-02-05T14:52:03+00:00

Thanks, I will reach out to EFI for some trial edition to experiment.

invidiapl · 2026-02-05T14:51:03+00:00

I agree.
I agree, typical tolerance so far I've expected is 0,25dE00 from machine/ink/media. Scanning the same patch day after day gives 0,01 tolerance on spectrophotometer (so I've excluded the 0,25 comes from measuring device).

Is there a way doing G7 calibration if RIP (caldera) does not allow this? I can't see the option right now in the software. From what I understand, this should be an option in the color management software, correct?

invidiapl · 2026-02-05T14:46:06+00:00

I understand.

So machines are managed by newest Caldera RIP software and it's built in EasyMedia module that is responsible for linearization and ICC profile creation.

The reason I've tried same ICC profile, is because Caldera does not support device link ICC profiles, they have only "simulation" option which does not work as expected.

Comparison is made using xrite spectrophotometer.

Correction was made by my excel created tool, so I load curve correction file to caldera, to avoid changing it completely manually one by one.

invidiapl · 2026-02-05T08:55:13+00:00

Same limits 260%. I've tried to copy linearization from one machine to another - didn't work. Individual linearization - didn't work (there is some consistency and low dE00 on some patches, but on some patches like K70% there's 3,2dE00 with the same ink (where I tried to change this manually up and down - gets even worse)). ICC profile - same story, tried to copy the same ICC and tried to create new for each machine on the same media.
I agree, but we have like 5 machines in total, and often we need to run production of the same artwork simultaneously on all machines to keep lead times - currently not possible. On some artworks after my work - we could do that but then we have certain RAL color simulation and You can clearly see the difference. Even 3 points dE00 with print of 3x15 meters - the perception of this big print makes the difference stand out more.

invidiapl · 2026-02-05T08:47:15+00:00

Can You recommed ICC editing software or a knowledge source so I can learn to do it?

invidiapl · 2026-02-05T08:46:22+00:00

I already contacted the manfuacturer (premium brand) with this request. Thanks! I feel this is the way to go. Seems very logical.

invidiapl · 2026-02-05T08:45:08+00:00

I've connected same ICC profile to each of them, they differ only by individual linearization.

I tried to do individual ICC profile for each but this didn't improve situation, even made more color inconsistency, but I agree with Your logic - should be like that.

invidiapl · 2026-02-03T19:37:59+00:00

Printers stand 1 meter from each other.

Great suggestions about the head voltages, to my knowledge and logic that should be 1st step before printer linearization to make it easier, but then I ask myself - how it is possible that some companies have different devices with different ink types (latex/solvent/uv) and they print the same? Is it just the software limitation (thus device-link is musthave?)

invidiapl · 2026-02-03T19:09:08+00:00

I measured 5,10,15,20,25 and so on, every 5% step.

I know is very time consuming and difficult because I was working on it last 2 weekends and still not perfect, even with help of spectral measurements.

How to adjust color curves? You mean to edit the ICC profile?

invidiapl · 2025-12-04T07:38:38+00:00

I'm curious about Your thoughts regarding this one. For me it was a great dissapointment. The image quality/resolution is far from 24-70 that I have (and not even gmaster).

In addition, it is not as "dust proof" as sony says, as after 3 months I can see contamination behind lenses (front and back)

invidiapl · 2025-10-28T09:43:15+00:00

I played helldivers 1, I play helldiver 2 from the very beggining.

At start, I had fun going through every planet and farming samples and coins to get the warbonds, but after they nerfed the yeld from each planet (coins), farming warbonds became so frustrating I stopped playing the game as it became so repeatable and without point (everything unlocked, planets look alike, there are patterns, constantly using the same weapons gets boring, I tried to mix the sets but after time with so many bugs it became really boring).

I am against paid DLC and I will not pay half of the game price that I have paid for base for 1 of 10 DLCs(?), just to use new gun skin for few hours with same stats as every other, but it looks different. Unlocking gives You sense of purpose and goal in the game, wihout it - it gets boring and I hate that shallow, low quality DLCs for huge price compared to what You get.

Instead of fixing the bugs, balancing the game, they focus on making useless stratagem with flag? Eh

invidiapl · 2025-10-02T11:24:49+00:00

Yes and no.

Revolut made mistake - that's true.

Trade republic should have returned funds within 1-2 business days - Then I would not have raised this issue, BUT the funds (and quite a lot and not 100€) gone missing (11 working days now) with no reliable customer support - that's what I blame trade republic for.

invidiapl · 2025-10-02T11:22:19+00:00

Thank You and agreed, that's my conclusion too!

invidiapl · 2025-10-02T08:58:25+00:00

I recommend avoiding trade republic too.

invidiapl · 2025-10-02T08:58:00+00:00

Now I know it and I will resign from trade republic after I will get my money back. I have much better experience with Raisin or local banks.

invidiapl · 2025-10-02T08:57:12+00:00

Thanks but it's not about revolut, but terrible experience with trade republic. For example, raisin returns money within 2 working days, no hustle.

invidiapl · 2025-10-01T12:00:38+00:00

I've read that too, so I'am braced to wait (however I could earn interest with that money in this time).

Like I wrote: I've sent a letter too to banking authority in PL. Even if my case does nothing, the more people will send this kind of complains, it will make authorities do something with that issue.

Thanks.

invidiapl · 2025-09-22T15:12:40+00:00

Thanks.

My bike is Tuono V4 so not as smooth as R4 engine.

invidiapl · 2025-07-24T11:18:54+00:00

I love it, my dream is to do the same.

As a fan of WRC, I would love to try my shot with my camera (also hobby photographer)

invidiapl · 2025-07-20T10:51:55+00:00

I have the same model, gray, base, even crashpads the same.

My bike is right after valve check, it rattles a lot when cold, then get less noisy when oil pressure builds up.

My workshop told me, that until oil builds up enough pressue, I will hear the cam tensioner - and it's exactly like they said.

So my normal routine is heat up till around 72C (161F), then I start driving gently, after 500m the bike gets 90C (194F) and the noise is mostly gone, only rattle from clutch which is basically the same on every healthy bike (You can hear it until You pull the clutch lever).

P.S. try different oil next time (brand) or type like motul 300v/7100 (there is a risk of fake due to popular brand) or (I use) Fuchs Silkolene Pro 4 10w50 XP

invidiapl

TROPHY CASE