Hardware Calibration – Benq SW321C

[Bogdan Boeru]

Hello,

Is there a way to use DisplayCal to calibrate the hardware LUT inside my SW321C? I do find that Benq’s software is a bit simplistic and I’m curious if DisplayCal would achieve a better calibration. I’m also hesitant to apply a DisplayCal software calibration OVER the hardware calibration on the Benq as that might induce banding.

So is there a way to make DisplayCal write in the actual monitor’s LUT?

Thanks!
Bogdan

[Vincent]

As any other HW calibration it uses propietary libraries to upload LUT data to USB, so you are forced to use the incomplete and innacurate calibration of Palette Master Elements.

AFAIK Benq lacks of a public SDK sou you cannot even “code” a way to store a DisplayCAL GPU 1D grey calibration for a native gamut HW cal and upload it, while HP and Dell have one and this can be done.

All the errors caused by PME like wrong white point because of wrong colorimeter correction on certain units (colorimeter firmware dependent error) or bad grey a*b* range due to bad quality not neutral panel response would need to use a GPU calibration on top of it.
On an AMD GPU since they have LUTs with high bitdepth and dithering there is no banding at all caused by calibration itself. Software color management implementatiosn add its own source of banding, but it’s unrelated to calibration.
On newer nvidias ther is a way to activate dithering on registry but it may stop working on some conditions, some caused by MS on Windows, some caused by nvidia. There should be a sticky thread here about how to enable it.

My recomendation is to calibrate with PME, as limited and innacurate it is, then verify resulting profile with DisplayCAL (better using actual colorimeter correction for backlight rather the innacurate one used by Benq… but you may choose to use the same innacturate one to find specific PME errors even if it measured OK).
See how bad it is for your particular unit using your particular colorimeter (if using one). Do not care about profile WP vs actual whitepoint, its a Benq ICCv2 error (stores PCS D50 whithout a way to recover actual WP).
If all is OK, your are OK.
If WP error is bad but all the others are OK and display looks “visually white” most people can live with it.
If there are grey range errors (total range considering al greys, not just individual vs reference) you’ll need to use GPU calibration on top of it. Otherwise you’ll suffer grey neutral errors.
If white is OK, grey range is OK there are other significative number of NOT OK patches and you use MS Windows, reconsider to “just profile” your display with a XYZLUT profile. It you change calibration tab settings to native/measured there should be no GPU calibration, just build a profile from actual DisplayCAL measurements, solving your issue for most image editing software. On MacOS you’ll be lmited by defective “dekstop” color management engine, so choose the lesser evil for you on that situation.

I would check uniformity too, since the vast majority of 27″ or 32″ benq widegamuts have color uniformity issues and/or destroyed contrast in exchange. That’s the reason they are not recommended displays having a 27″ Eizo CS for less money that that 32″.
You may had luck with your unit, but chances to get a good one with Benq are bad.

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