Re: Epson canned profiles
Re: Epson canned profiles
- Subject: Re: Epson canned profiles
- From: Andrew Rodney <email@hidden>
- Date: Tue, 17 Apr 2018 10:38:27 -0600
On Apr 17, 2018, at 10:15 AM, ben <email@hidden
<mailto:email@hidden>> wrote:
>
> On Apr 17, 2018, at 6:02 AM, email@hidden
> <mailto:email@hidden> wrote:
>
>> If you inhabit the "dE differences of .85 at the 6ish L value level make no
>> difference”-world then it does not discount all the people who that would
>> make a huge difference to.
>
> I've avoided getting into _why_ Andrew is spouting nonsense about the
> supposed insignificance of 0.85 dE because I couldn't even get him to put any
> actual data to his claims, but I think it's very much worthwhile having a
> side discussion on that point.
>
> Yes, Put a pair of patches side-by-side that differ by 0.85 dE and most
> people would be very, very hard pressed to tell you which is which.
It's invisible to the Standard Observer. As to your need to speak for most
people or everyone, it's troubling and a tad foolish.
> But even more important, especially with respect to profiling, is that you
> can pick basically any pair of colors that differ by 0.85 dE, place them
> adjacent to each other with no space separation, and the line dividing them
> will be instantly visible to everybody. You might not be able to describe the
> difference, but that there's a line between them will be obvious.
>
> Which is why we don't use seven-bit color.
You don't seem to understand the differences between device values and color or
device values as their result of encoding of numbers; that's why we don't have
7-bit 'color' (device values).
When encoding 16-bits per color, the math allows us to define billion’s of
color values, but that doesn’t change the fact we still can’t see all 16.7
million color values in the 24 bit encoding of these pixels. As such, it’s best
to talk about encoding as having a potential to define millions or billions of
numbers, DEVICE VALUES, that could be associated to a color value and thus
color, if we can see them. If you can't seem them, they are not colors.
Don’t confuse a color number, a device value based on some encoding of simply
numbers, as a color you can or cannot see!
Educate yourself:
http://digitaldog.net/files/ColorNumbersColorGamut.pdf
<http://digitaldog.net/files/ColorNumbersColorGamut.pdf>
> I would hope that everybody here is well familiar with how easy it is to see
> banding in eight-bit gradients. Banding in a seven-bit gradient is far more
> glaring -- and the difference between steps in a seven-bit gradient is a mere
> 0.78 dE.
You don't seem to understand the differences between device values and color or
device values and encoding of numbers; that's why we don't have 7-bit 'color'
(device values).
Educate yourself:
http://digitaldog.net/files/ColorNumbersColorGamut.pdf
<http://digitaldog.net/files/ColorNumbersColorGamut.pdf>
You think that the vast majority of printers send more than 8-bits per color to
the print driver? VERY few due and the result isn't banding on the print. High
bit data is about editing overhead such we can send the best 24-bit device
values to the printer. Now if you had a lick of experience using Epson printers
on the Mac, with some of their drivers, you'd be able to run actual visual and
colorimetric tests sending high bit (16-bit) data to that driver. Then you'd
know, from actual experience and testing that there's no difference sending
high bit or 24-bit color to such a printer! One can do this with a 3880 for
example, on the Mac, there IS a 16-bit check box in the driver.
> So Andrew's blather about how a difference of 0.85 dE in profile building is
> invisibly meaningless is exactly equivalent to a claim that 7-bit imaging
> ought to be good enough for anybody, and his pouting that you can't identify
> the difference between 0.85 dE samples is irrelevant.
You don't seem to understand what a 0.85 dE of one patch, an invisible
difference means in the grand scheme of things.
> It further illustrates a very disturbing shortsightedness on Andrew's part.
> Profiles can be used for spot color matching, yes, but that seems to be the
> Alpha and Omega of Andrew's goal in profile building. For everybody who's not
> printing corporate brochures where the company logo has to be the right
> Pantone number, profiling is all about image quality, especially fine detail.
> Open shadows and clear highlights in black-and-white fine art; smooth (and
> natural) skin tones in fashion and portraiture; that sort of thing.
It further illustrates a very disturbing (to your) aspect on my part; totally
dismissing your misinformation about ICC profiles and Epson driver settings
being a problem. As I said two days ago, and further proved, there is no such
problem.
> Missing the black point by 0.85 dE might not be as big a deal for a printer
> as well linearized as the new Epsons appear to be, but that would be entirely
> thanks to Epson engineers.
Nothing is missing, there's a difference (distance) between two device values
that equate to 0.85 dE 2000. That you believe something is missing shows you're
missing an understanding of what two device values with a dE 2000 of 0.85 mean!
> Indeed, I wouldn't at all be surprised if you'd get more detail from a matrix
> profile than from one made the way Andrew's been describing.
More assumptions; guessing is easy. Why not provide one post with some
colorimetric data?
> ...which is why context is so important.
I suspect only for you.
> Miss some super-saturated yellow by 0.85 dE and nobody will care. Miss the
> black point by 0.85 dE and some will.
There's nothing missing, again! There's a difference; that's it.
Andrew Rodney
http://www.digitaldog.net/ <http://www.digitaldog.net/>
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