My impression is that the DISCUS has worse matching to standard observer CMF
than i1D3, so it needs precise calibration for a given backlight spectra. The
difference in low luminance reading and inter instrument agreement is not night
and day, the measurement is much slower. Personally I had sold it and kept
Marcin Kałuża, Artis
+48 604 466 330 | +48 12 290 65 40
On 22 Sep 2017, at 02:58, Graeme Gill <graeme@xxxxxxxxxxxxx> wrote:
James Finnie wrote:
It's hard to know isn't it - there is a general dearth of good
quality data out there for these devices and the spec sheets
themselves are "looser than a wizard's sleeve"... Vs the i1d3 they do
at least specify chromaticity is valid down to 0.05cd/m2 - whereas
I1d3 only specs luminance down to 0.1cd/m2 with no real indication of
what can be expected of the chromaticity readings below 100cd/m2.
A while back I did a comparison between the i1d3 I have and the Klein K10,
both calibrated to a JETI 1211, and the i1d3 tracked rather well, given the
great disparity in price.
The individual "certificate of performance" sheet received with the
Discus unit I just took delivery of claims a verified 0.0017-0.0021
dE(xy) avg for 439 colour samples against 4 different LCD display
backlight technologies using the inbuilt calibration matrices. Seem
like impressively low numbers.
I'm sure it's a higher quality, more capable instrument. But is
the improvement worthwhile for most people ?