Re: Epson canned profiles
Re: Epson canned profiles
- Subject: Re: Epson canned profiles
- From: Steven Kornreich <email@hidden>
- Date: Mon, 16 Apr 2018 14:56:44 -0600
Sorry guys I didn’t mean to start a huge debate the reason why I first posted
the question was my beloved Spectrolino/Scan finally died last week and started
using new Epson branded papers and was curious on if it had mattered if I
printed at 1140 or 2880 on my P500 I called Epson support and they had no clue
at all in regards to my original question
__________________________________
Steven Kornreich
email@hidden
http://www.kuau.com
> On Apr 16, 2018, at 12:18 PM, Andrew Rodney <email@hidden> wrote:
>
>> On Apr 16, 2018, at 12:03 PM, ben <email@hidden> wrote:
>>
>>> On Apr 16, 2018, at 10:18 AM, Andrew Rodney <email@hidden> wrote:
>>>
>>> THREE different settings in the print driver to make 918 color patches.
>>
>> Just to make sure I'm understanding your workflow...
>
> You don't. At all!
>
>> you have a 306-patch chart that you print three different ways?
>
> 918 patches per target. Three different print parameters changed in the Epson
> driver as outlined for English speakers, between the two print samples.
> Measured on an iSis XL and not totally dried down. The differences (Avg dE)
> between the two targets are INVISIBLE. Hence, no problem as you suspect,
> assume and are incorrect in stating.
>
>> And then you read each chart independently, merge all samples into a single
>> results file with 918 samples, and generate your profile from that?
>
> Have you ever measured a target for a profile? Ever saved CGATs data and used
> software to compare the dE of the measurements? Seems not.
>
>> (Seems weird and highly questionable without some solid colorimetric data to
>> back up such an approach...so either you've got that sort of data or I'm
>> misunderstanding your workflow or your workflow is invalid.)
>
> Because you're so confused!
>
>> 5000 patches, the average dE was 0.5!
>>
>> Yes, that's maybe a tenth or two of a dE better than what Argyll generates
>> on an iPF 8100 with similar-sized charts.
>
> You are confused again. The difference (distance actually) between 5000 color
> patches, the average from two of the same Epson printers is 0.5 dE 2000.
> Invisible.
>
>> But you're still not even pretending to answer some really, really basic
>> questions.
>
> You're asking silly questions and I refuse to answer with silly answers.
>
>> You've told us how tight a fit your profiles are to the measurements you've
>> made, which is probably good.
>
> No I did not. You're confused a lot. This has ZXERO to do with ICC profiles.
> There's no reason to introduce that into the mix. I'm telling you the
> measured differences in either 918 or 5000 color patches from printers that
> are measured.
>
>> (It's possible to over-fit to the detriment of profile quality...probably
>> not a problem with a thousand-patch chart on a modern printer, but a decade
>> ago I would very much have suspected over-fitting with the numbers you
>> supplied. And, if you really are only sampling a few hundred locations in
>> the printer's color space, I'd definitely start to suspect over-fitting --
>> especially since the triple redundancy may well trick the profiling engine
>> into over-emphasizing those locations.)
>
> Go onto the topic and don't go into areas that will only confuse the
> discussion.
>>
>> But I'm asking a trivial question completely unrelated to profile fit.
>
> This has NOTHING to do with profiles Ben. It has to do with device behavior
> before profiles are built. Data that is measured to create a profile.
>
>> What, exactly, in D50 L*a*b*, is the darkest color the printer generates
>> with the most economical setting? And what does it generate with the highest
>> quality setting?
>
> Doesn't matter. You're asking about ONE color and I'm provding data about 918
> or 5000! It appears you have no idea how to read a dE report, what the
> average of thousand of meaured colors tell us about color differences
> (distance) of two sets of samples.
>
>> You've got your just-printed chart there in front of you, right? And you
>> just measured it, no?
>
> Yes. How else do you think I made the dE report in ColorThink Pro? Unlike
> you, I'm actually measuring data on an iSis XL and comparing actual
> colorimetric data.
> You're making stuff up.
>
>> Unless you're doing something utterly bizarre, at least one of the patches
>> on that chart will be R=G=B=0.
>
> I'm not doing any bizarre utterly or otherwise. What's bizarre is that you'd
> come onto this list with such a poor understanding of colorimetry.
>
>> All you have to do to answer this very simple question from me is find that
>> patch in your measurements, once for the one setting and another for the
>> other setting, and report what the measured D50 L*a*b* (or XYZ or other
>> absolute coordinate system) values are.
>
> I answers 917 and 4999 questions of colorimetric data.
>
>> Is it really so hard for you to understand what I'm asking for?
>
> Is it really so hard for you to understand how we measure color and produce
> dE reports of output?
>
>> Really so hard to answer it? Really so hard to understand why it might
>> matter? Really so hard to believe that, whatever Epson is doing today, it's
>> been a source of challenge in the past?
>
> Is it so hard for you to understand that what you state is rubbish and
> unproven colorimetrically? This from a fellow with NO experience with Epson
> printers. Sad.
>
>> I mean, it seems like not that long ago that forum posts were about nothing
>> but printer dMAX this, dMAX that -- obsessing over which made the darkest
>> blacks, which ones were problematic because the lowest L* colors they could
>> print were so far off the neutral axis, and so on. Sure, technology has
>> improved dramatically...but do you really expect us to take your perfectly
>> unremarkable error fit report as evidence that Epson's dMAX is the same
>> regardless of driver settings?
>
> Posts you appear not to have understood.
>
>> ...er...you _do_ know what that error report is, right? You supply your
>> profiling engine with the RGB values you printed and the L*a*b* (etc.)
>> values you measured from the print. The engine builds an ICC profile that
>> maps requested L*a*b* values to RGB values to send to the printer. Your
>> report is the result of taking your measured L*a*b* values, running them
>> through the profile, seeing what RGB values the profile generates, and
>> comparing them with the actual RGB values you sent to the printer. In other
>> words, all you've done is tell us how tightly your profiling engine was able
>> to fit the profile to the measurements; you haven't told us anything about
>> the measurements themselves....
>
> Bla, bla bla. The more you write assumptions and FUD, about the behavior of
> Epson printers, the more there is no doubt:
>
> It is better to say nothing and be thought a fool than to open your mouth and
> remove all doubt. - Abraham Lincoln
>
> Andrew Rodney
> http://www.digitaldog.net/
>
> _______________________________________________
> Do not post admin requests to the list. They will be ignored.
> colorsync-users mailing list (email@hidden)
> Help/Unsubscribe/Update your Subscription:
>
> This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
colorsync-users mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden