Yahoo Groups archive

QTR-Quadtone RIP

Index last updated: 2026-04-28 23:12 UTC

Message

Re: [QuadtoneRIP] Re: Trouble with Custom QTR Curves

2016-04-20 by Paul Roark

​See The International Color Commission Wiki page


Paul

On Wed, Apr 20, 2016 at 10:14 AM, artodd138@... [QuadtoneRIP] <QuadtoneRIP@...m> wrote:

I'll jump back in for a second to clarify my initial question. Brain hit upon my question when he said,


"Let's suppose we are in a room with no monitor, so no concept of matching. We place a piece of paper in front of a viewer with a series of unlabelled, evenly-spaced grey patches, i.e. evenly spaced luminosity values, ranging from white to black, and ask them if they are evenly spaced. It's my understanding that they would say no. So the question is, what series of patches would they consider evenly spaced? Again my understanding is that if the evenly spaced luminosity patches are converted to an ICC from QTR-Create-ICC and reprinted, then the observer would probably say yes."

Brain is correct that I wasn't referring to print-montior matching rather a visual perception of evenly spaced values on a print. If we achieved a print in which a standard observer agreed that the values are evenly spaced from pure black to pure white, then measured and graphed those patches, what would that graph look like? For me, the goal is to achieve a print in which I can produce perceptually evenly spaced steps from dMax to dMin with smooth gradations. If I can achieve that, and it looks right, I'm not concerned if the measured L* values are perfectly linear or not. In my experience, most prints are viewed exactly as described in Brain's hypothetical, "in a room with no monitor, so no concept of matching."


Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.