xrite i1Studio

Started 3 months ago | Discussions thread
NAwlins Contrarian Veteran Member • Posts: 6,611
My experiece my more like Rich's
1

Maybe there are significant instrument to instrument variabilities? Are you using the most up to date software?

I’ve used two with the older Xrite brand and one with the new Calibrite logo. Exactly the same behavior.

Everything software wise is the latest stable version, both native software and OS. When I tested with Argyll it was the latest version.

Anyway as I wrote before it’s mathematically impossible to have optimum profiles with such a low number of patches.

At the outset, I've been pleasantly surprised by how well prints made using ColorMunki / i1Studio ICC profiles have matched the screen. Now to the details:

Uh, mathematically impossible to have optimum profiles with such a low number of patches?! Maybe this is showing my ignorance, but it seems to me that if the printer were perfectly well-behaved and linear, then theoretically one could create optimum profiles with as few as 27 patches. How many patches you need with any given real-world printer seems to be in part a function of how well-behaved and linear the printer is. It also seems to be in part a function of how well the software can predict where the non-linear areas will be and use a patch set tailored to mapping those nonlinearities.

The traditional approach is rather brute-force: create a patch for every combination of R, G, and B inputs with the ranges dived into N steps, which requires N^3 patches. So for example if the range for each of R, G, and B is 0 to 255, and you divide that range into 9 steps (like 0, 32, 64, 96, 128, 160, 192, 224, and 255), then you have to print and measure 9^3 = 729 patches. If you use 12 steps, then you need 12^3 = 1728 steps--and with that, the permutations use steps that remain 23 out of 255 apart from each other--maybe enough room for significant nonlinearities.

But there are a variety of strategies for getting better results from a given number of patches. X-Rite seems to use a quite clever one with the ColorMunki / i1Studio software. The first set of 50 patches is always the same, but the second set of 50 (or 100 for B&W) is custom-calculated. If the software can, from measurements of the 50 standard patches, make very good estimates of where the nonlinearities are, then it can create an equally-good or even better profile with a far fewer number of patches.

You always get very “sharp” spikes near primary and secondary colors with rough and flat approximations of the gamut, as it doesn’t have enough data to approximate near gamut limit colors.

No, I don't.

Comparing a 420/840 profile with a native ccStudio one the volume is almost similar, but the latter is sharper, flat edged and full of approximations, while the former has the expected typical shape of a pigment printer gamut.

My i1Studio-made ICC printing profiles have what look to me, when viewed in 3D at ICC View, have what look like normal contours, including compared to 'canned' profiles.

I also profiled an Epson WorkForce printer, which is not meant for real photo printing, just for the sake of it. I paid for a single matt paper profile with close to 1000 patches, then I profiled the same paper and few other by myself. The former is just what you expect: a quite small gamut with a different yet regular shape. My profiles however are very oddly shaped, with the volume going outwards and inwards where you wouldn’t expect, with a similar shape (different volumes) across several matte and glossy papers.

Yeah, I think either you're doing something wrong, or there's a hardware problem with the device(s) you used.

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