On Nov 27, 2006, at 6:24 PM, Scott Martin wrote:
“Since XRite's linearization is chroma based you'll still want to have a UV filter for the best results”. Can you explain?
Their lineaization doesn't just linearize for density, it linearizes for neutrality. They way they have it implemented now optical brighteners can throw off the linearization with non UV devices. So, if you use XRite's linearization feature in either ColorBurst or MonacoProfiler you need to have a UV filter (at least when measuring papers with OBs).
I disagree with the above on a couple of points.
First, ColorBurst does NOT require a UV-cut spectro for linearization. This ONLY applies if you use one of their supplied linearizations (technically, you've have to use a UV-cut Pulse if you wanted to use a ColorBurst "factory" lin; even a UV-cut Eye-One would give you different results) but if you're building a linearization from scratch, you can use any instrument you want.
So, if you re-lin using one for their supplied lins, you should use a UV-cut Pulse. If you're building your own, doesn't matter.
Second, unless they've changed something, they linearize for NEITHER density nor neutrality; their linearization is chroma-based. What I mean by that is the chroma response of a specific ink channel and paper is made "linear" or, to put it another way, the linearization curve is adjusted so chroma values are evenly spaced throughout the tonal scale. With typical inkjet behavior (Epson Ultrachrome for example), you generally cannot have linear chroma on each ink channel AND gray balance/neutrality at the same time. It's one or the other.
Thirdly, the Linearization Feature in ColorBurst and MonacoPROFILER are two different things. ColorBurst linearization is a distinct step completely separate from profiling. MonacoPROFILER's linearization on the other hand is part-and-parcel of profiling. Once you feed it the linearization data from a special Monaco chart, PROFILER actually creates a CUSTOM profiling testchart optimized for that device based on the linearization data.
The difference is that ColorBurst is DIRECTLY affecting the output of the inkjet device whereas PROFILER's linearization is NOT affecting the inkjet device at all but they are instead altering the profile testchart to better map the inkjet's behavior.
2 UV or not UV? That is the question!...
OK, now, back to our regularly scheduled programming.... :-)