Recently I got access to the Z3100 Software Developers Kit. I am using it to develop some interesting apps that hopefully will be of interest to all Z2100/3100/6100 users.
While developing my apps, I discovered what I thought was a bug but turned out to be a "feature" in the Embedded I1 spectro aka ESP.
Here is what I sent to the HP developer support:
Basically the embedded spectro in the Z3100 is advertised as having a range of 400nm to 700nm in 20nm increments for a total of 16 measurements. It is also advertised as using a UV cut filter. What I am finding out is that what I really get are readings from 420nm to 700nm. 400nm readings are always 0. This is either a bug or a feature depending on your point of view. Ultraviolet light is generally considered light with a wavelength less than 400nm. So depending on the strength of the UV filter in the spectro, not having a reading at 400nm could be normal. But if it is, then all of HP's documentation is wrong! The specs should say 420nm to 700nm in 20nm increments for a total of 15 measurements. The reason all of this is important is because to generate accurate color profiles, the profiling package needs to know if the paper being profiled is using Optical Brightening Agents (OBA's). If OBA's are present then the profiling software may need the information at 400nm to properly compensate for them.
Here is there response:
The integrated UV cut filter (or actually, bandwidth limited illumination)
eliminates all signal up to and including at 400 nm, which is why that value
is always set to zero. The reason for this is that 400-700nm is a standard
spectral reporting range, whereas 420-700 would not be. We agree that this
can be confusing, but once you know what to expect it shouldn’t be a
problem. Regarding OBAs, there is no way to detect them with ESP, exactly
because of the integrated filter (or illumination).
They also sent me a wonderful PDF that explains in great detail how the ESP compares with other spectros. It also goes into detail some of the design limitations that had to be overcome.
Bottom line is the spectro in the Z series is very good indeed.
Enjoy
Jim
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