Originally Posted by lovingdvd
Thanks Manni. I thought I read that it was calibrated for BH1886 but I agree that the gamma graph doesn't seem to reflect that. Also an odd bump/dip in the top end from what I remember.
The main thing I took out of the calibration report was that delta L was high on all 6 colors - which is a good thing since it means the colors can be adjusted without lowering the overall white point. It would be great to see how the colors track natively, how well the internal grayscale and CMS controls work, and how well everything calibrates with a Radiance. I know that with my VW95 controls all at neutral and with using the Radiance I have dE's from 5-100% all under 0.5 and all under 1.5 for all colors including inside the cube across the entire ColorChecker SG results. That's extremely tight and I'd want the same out of the Epson.
Unless I missed it, I can't see anywhere the gamma curve target. Scott says the target for the gamut was rec 709, but that doesn't say what the gamma target was.
A 21 steps report for greyscale is needed when targeting BT1886 because the 5% point is the most important one in that case (that's the point where the impact of the black levels of the display on gamma targets have the most significance). There is really no way to assess a BT1886 curve with a 10 point graph/data.
Just to illustrate the point we were trying to make regarding how necessary it is to show how saturations track before/after calibration, I attach three graphs from a JVC rs49 (using my Discus trained to my i1pro2).
On the first graph, you can see how saturations track after setting the white point to D65. It's not perfect, for example if you look at red it's oversaturated at 100% but overall it's only a bit oversaturated at 75% sat and below, so red wouldn't look too bad with actual content using the default profile (standard) untouched, especially after a decent greyscale calibration.
On the second graph, it shows how saturations track using the JVC CMS controls to set red at 100% sat exactly to its rec-709 target (I only tried red because I wanted to check if the CMS was still behaving the usual way on the new models). It looks perfect, but the points at 75% sat and below are significantly undersaturated, which produces a very visibly undersaturated picture. Because there is much more information there than at 100% sat in actual content, a trained eye like Scott would say that this calibration looks undersaturated, and he would be right, even if a report showing only the points at 100% sat would make it look like he was wrong. This could very well have happened with the Epson: 100% was calibrated exactly to the target as shown in Kevin's report, but 75% and/or below could have been oversaturated, which might have caused Scott's impression that red was too strong. If you showed a report of the three calibrations attached below with only the points at 100% sat like in Kevin's report, this would be the most "perfect" looking calibration, yet it would be the one giving the worst results: it's way more undersaturated than the initial one is oversaturated.
On the third graph, it shows how you have to calibrate red at 100% sat to get a decent balance between the various saturation points. It has to be slightly oversaturated at 100% sat so that it's less oversaturated than when left uncorrected, but the other points are not as undersaturated as if you were trying to reach the exact rec-709 target at 100% sat, like in the second graph. In other words, to get a good-looking calibration (by this I mean accurate) using the JVC CMS, you need to get a report which doesn't look perfect at 100% sat.
Sorry for the long-winded post, but I just wanted to illustrate why a report like the one attached above doesn't say if the calibration is good or if the internal controls of the Epson can produce a good calibration or not.
Showing saturations, you can see that while the JVC CMS isn't perfect, you can get a very decent calibration with an imperfect report at 100% (third calibration), or you can get a poor calibration with a perfect-looking report (second), but you can't get both at the same time.
I'd like to know what's the situation with the Epson, if only to know whether it needs an external 3D LUT or not to produce decent results.