Monitor calibration - 3D LUTs for colour space emulation

richard

2C from me

I agree with this statement you wrote

"I 'program' my BenQ SW2700PT monitor to AdobeRGB, the profile I use is the standard AdobeRGB profile.  If it's been done properly there should be no need to have to characterise the monitor and produce a profile unique to that monitor. 

If I understand correctly what you want [accurate calibration to a standard], its a situation not unheard of in our industry - that’s what's been largely achieved in the world of offset and flexo. print.

The work of the print experts at BVDM, FOGRA , PSO and GRACoL has enabled the standardisation of CMYK file separation for most sectors of the print industry.

Yes, ICC profiles are used in the separations to CMYK, but all the data from any user (for the same target sector) is the same - it's a standard space not a custom ICC for each press. Kind of what you'd like with sRGB and displays.

Also, what you apparently seek is pretty close to what the video industry does in edit suites largely using LUT boxes. Calibrate with a hardware LUT, then chuck the unaltered data through that [no ICC profile - there is no mechanism for a profile] and it looks "right".

but I don't agree with this statement:

"That's 'old school' thinking.  If I do attempt to characterise and profile the monitor, the profile I get should be the same as that of the standard AdobeRGB profile, within the bounds of accuracy of the process.  It's a pointless procedure."

It's not old school to use ICC profiles in display situations where accuracy is needed. It's actually a great way of getting good (or at least acceptable) visual performance out of non ideal fairly low cost displays.

As you've seen its hard to achieve what you desire at low cost, maybe that’s why BenQ can't do it.

What you are describing [calibration (or programming) only to a standard space] is what Barco used to do (at massive cost) - and Colormatch too - long in the past. That's old school.

When HP and Microsoft came up with sRGB it was with the idea that it could be used to characterise the "average" display - [sRGB is based on the display characteristics of consumer-grade CRT monitors manufactured in the early 1990s].

But IMO sRGB's not good enough for

A: accuracy (displays are generally not consistent and most do not have the mechanism for accurate calibration)

B: those who sensibly like to use larger and various document color spaces* with print in mind.

     [*yeah a TRUE Adobe RGB capable and calibrated display would largely solve that but at what cost for a display that can 100% match Adobe RGB!]

c: those who want to make the best of far more capable [increasingly wider gamut] display systems

And, this is a good point:

"It could be argued that sRGB is the most important profile to emulate accurately, because it is the profile assumed by applications that don't colour manage."

Right, agreed.

But we need to get rid of applications that don't color manage, not dumb everything down to sRGB.

But what this conversation is all, about is, it seems,  proving that your BenQ display is incapable of what you want, a true emulation of sRGB, and asking us to agree - end of story.

We agree. It can't, but we don't care because an ICC profile used with a savvy application solves the issue.

The wide gamut display of course introduces another conundrum. Non color managed applications are useless on these displays - yes you could limit the gamut to sRGB but would you? Why pay for 98% of Adobe RGNB and do that.

ICC color management solves the problem, at least for intelligent applications.

Good hardware calibration displays can do it - basICColor SW claim to properly match sRGB with emulation in their display SW on both Eizo and NEC.

In your ideal world where ICC profiles are not needed, it seems -  everyone with a computer who is viewing images requires a high quality hardware calibration display [constrained to sRGB). That's not going to happen anytime soon and sRGB . is not the way the industry is going, in the interim we have the well tested and successful solution of ICC profiling.

If what you seek is a world where "calibrated (or programmed)" displays come off the production. line that may be some time in the future. And even if they do they likely will not be sRGB.

It's what HP seem to have achieved with may of their simple photo printers, sRGB files print pretty well and making custom profiles often may not improve upon that.

But it's unlikely to happen for displays

I hope this is of interest

thanks

neil barstow, colourmanagement