Submitted by deejjjaaaa on
Forums:
I can use a friend's ColorMunki spectrophotometer, but I was wondering if it is decent enough to measure a target, so for example, I made a fresh .cie today for QP 202 and compared vs .cie supplied with makeinputicc = http://postimg.org/gallery/2lny8xm86/
so - shall I try procure something better elsewhere and redo all my measurements or those results look normal (nothing out of the ordinary) ?
Image:
With deltaE of about 1 I
Submitted by Iliah Borg on
With deltaE of about 1 I would not even start to worry ;)
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Best regards,
Iliah Borg
does it make any practical
Submitted by deejjjaaaa on
does it make any practical sense to repeat the measurement (__the same__ ColorMunki instrument) and average the results for __the same__ target or it will be a snake oil ?
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I do not think it makes sense
Submitted by Iliah Borg on
I do not think it makes sense to reperat the measurements - the results confirm that the target cie is close to the actual target, deltaE is mostly due to precision of the instrument and the results of consequative measurements will be skewed by repeatability.
The tech specs are:
Inter-Instrument Agreement Average 0.6 DE2000, max. 1.5 DE2000 on X-Rite factory standard Short-Term Repeatability Typical 0.1 DE2000 on white
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Best regards,
Iliah Borg
I also have 2 more .cie files
Submitted by deejjjaaaa on
I also have 2 more .cie files of yours:
"QpCard202and203_2deg_Lab.cie"
and
"QpCard202and203_10deg_flared_Lab.cie"
and there the difference is much, much bigger - there shall be some reason why makeinputicc does not use (I mean is not supplied with) those 2 ?
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The reason is that 10°
Submitted by Iliah Borg on
The reason is that 10° measurements are not supported with current profiling tools; and "no flare" conditions are something one can get only in a very tightly controlled environment in repro work (like I was doing for museums).
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Best regards,
Iliah Borg
do you know why the Lab data
Submitted by deejjjaaaa on
do you know why the Lab data ("Lab values representing D50 2deg calculated from spectral data") printed on the back of the actual QP202 card (at least on my copy) is __different__ from Lab data supplied by QP itself on their website ( www.dropbox.com/sh/nyxy0ht4zwkuuxb/8nlcBRk0At/QP203references.zip ) ?
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Submitted by Iliah Borg on
Seems that your measurements are in good agreement with mine, so the cie files are usable. I can ask, of course (and you can ask, too); but I doubt we will get any real answer apart from "use the measurements printed on the card" - which, incidentally, I would not use if they disagree with my measurements.
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Best regards,
Iliah Borg
but then one might ask a
Submitted by deejjjaaaa on
but then one might ask a question - what data QPCard software itself is using when making DCP (or ICC with plugin - which I don't have one) profiles... if they are using anything like the data from their own website or the one printed on the card - that is quite different from what people are actually measuring (mr Pereira's file supplied with makeinputicc, yours - "Seems that your measurements are in good agreement with mine", my own amateur measurment with ColorMunki)... so how come ?!
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Good question, and I think
Submitted by Iliah Borg on
Good question, and I think the answer is to use ICE or Hopper ;)
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Best regards,
Iliah Borg
I managed to borrow i1pro2
Submitted by deejjjaaaa on
I managed to borrow i1pro2 (ergonomics is way better than colormunki, I had to start with i1pro2 instead of colormunki from the very beginning !) to retest measurements and I have two questions
1) does it make sense to use the data obtained for "M1 measurement illumination conditions" instead of "M0" for targets where the resulting .cie file (spectral data) will be used for camera profiles generation ? spectral data is different between M0 and M1 - which one is more suitable for profiling intended for daylight conditions ? sounds like M1, right ?
and
2) does it make sense to use "XRGA" or not (I am using BabelColor Patchtool patch-reader and it offers this option) ?
Thank you.
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