Color Spaces CIE and Adobe RGB

[Hudechrome]

Looking at monitor specs, usually, the color space of the monitor is given in terms of a target color space, like 96% Adobe RGB. Some give several, but along comes Dell, u2412, and they supply one: 82% CIE.

I know what CIE is, but making a guesstimate from the Dell spec requires more than what I presently know about such matters.

So, what are the expectations? Is that a meaningful spec for comparison sake? IOW, how much does Adobe RGB enclose CIE 1976?

TIA

Lawrence

[Chris Cox · Accepted solution]

CIE is a standards body.  There isn't really a CIE colorspace (well, there are many that have different names and don't apply to monitors).

So I'm not sure what they're referring to.

[Hudechrome]

Exactly. That's whay it's confusing.

I believe they are referring to this:

http://hyperphysics.phy-astr.gsu.edu/hbase/vision/cie1976.html

[c.pfaffenbichler]

I guess what they are trying to express might be that their monitor can reproduce 82% of all humanly perceptible color impressions.

But such a percentage number would not define a color space as it does not clarify which regions of CIELAB can and which cannot be reproduced by the monitor (not to mention that (edit:) monitor-ageing would probably also be a factor).

As for how »large« AdobeRGB is one can (on Mac) use ColorSync Utility to compare color spaces’ geometrical representations.

[Hudechrome]

That won't work as I am on PC. Further, it still will not give me any relative information as to the expected results from the monitor itself, since they haven't offered such a representation for the monitor.

It may be moot at this point as I thought I might score one that is advertised locally. Apparently, it was a Christmas gift insufficient (too small) for his needs. It seems to have been snapped up.

Yet it would be good to know. I suspect that it was their way of avoiding any discomfort as to it's real world performance.

[Chris Cox]

The "CIE diagram" is misleading (someone copied a graphic without knowing what it meant) -- CIE has many possible colorspaces.

It could be based on CIE XYZ, xyY, LUV, LAB, etc.

[Hudechrome]

From the Dell Spec:

Color Gamut

82% (CIE 1976)

From the attached link:

http://en.wikipedia.org/wiki/CIELUV

CIE 1976 corresponds to CIELUV (don't ya just luv it? )

I assume, since the transformation equations are specified, that some sort of transformation to Adobe RGB can be made, but I'm strictly out of my element here.

Seems an awful lot of work just to make an appraisal of their offering.

[Chris Cox]

There were a handful of standards from CIE in 1976.

Sigh, I just love advertising copy written by people with no idea....

And CIELUV is open ended, just like CIELAB.

If you could send me a link to the display in question, we can follow up with Dell about their not-quite-right advertising.

(the CIE and ICC lists should get a laugh out of it)

[Hudechrome]

Here it is. Check the spec tab

http://accessories.us.dell.com/sna/productdetail.aspx?c=us&cs=04&l=en&sku=320-2676

"(the CIE and ICC lists should get a laugh out of it)"

Just so long as it doesn't degenerate into that brouhaha you and Murphy had with that fellow calibrating for video a few months back. I'm on that list and really enjoyed lurking, although I actually e-mailed the fellow and looked at his website.

Still don't know what set him off so.

[D Fosse · Accepted solution]

From TFT Central:

The U2412M uses White-LED (W-LED) backlighting. The colour space of this screen is approximately equal to the sRGB reference and is considered a 'standard gamut' backlight type. Studying the detailed panel spec confirms the screen covers 71% of the NTSC reference, 74.3% of the Adobe RGB reference and 95.8% of the sRGB space. As a side note you will see reference on Dell's website of an 82% colour gamut. This refers to the NTSC coverage but is based on a different reference point (CIE1976 = 82%). More common is the CIE1931 standard which would equate to 72% NTSC which is more relevant when comparing with other screens quoting NTSC gamut specs. While a 95.8% coverage of the sRGB space is decent enough and in line with most W-LED backlit screens, some higher end uses may require a wider gamut with a full 100% sRGB coverage (and beyond) for graphics and colour work. A wide gamut screen is another option for those wanting to work outside of the sRGB colour space.

http://www.tftcentral.co.uk/reviews/dell_u2412m.htm

[Hudechrome]

Thanks for the link. I need to bookmark that site.

[Hudechrome]

Quite the site! How did I ever miss it doing the Google Search!

So, the dilemma. It actually appears damn good for my b&w work, which has primacy here. I am especially gratified to see the linear relationship between contrast and brightness, which means that when I compare the print to the screen, the screen can be set not to shout!.

But then, the color. That it cannot even do 100% of sRGB is depressing. From a practical point of view, the times when I did see an extended color while editing in ProPhoto or Adobe RGB compared to switching to sRGB is pretty small, but when it showed up, it certainly did.

I suppose a way out would be to go with it for now, then at a later time upgrade to another, but keep the 2412 as a second monitor, maybe dual cards so that I might keep it's profile, then use it for b&w if the  high end is a ccfl.

Decisions, decisions!

[D Fosse]

Wide gamut is very nice if you have it, especially for someone like me who work mostly for offset print and usually stay in Adobe RGB throughout.

But I'd still put it pretty far down on the priorities list. I managed very well without it. So if you have your hands on a 2412 and it's otherwise good, I'd say go for it.

[Hudechrome]

I missed the craigslist posting. It went practially instantly!  But even at full price, especially since I got an Amazon gift card, It's a bargain. I checked out several competeing versions like the closest HP and it's more money.

[Hudechrome]

One aspect I haven't gotten around to (missing my usual roundtuit on my desk lately!) is what exactly (or approx, if that's all there is) does my Epson 3800 cover? So I started a search and instantly, some work done by Eric Chan showed up:

http://people.csail.mit.edu/ericchan/dp/Epson3800/gamuts.html

Not only does he use the 3800, he also has a monitor which does not cover aRGB, but sRGB.

The conclusions are interesting, along with his methodology. I realize it's 3 years old but then, so's my 3800!

So D Fosse is philosophically right on.

You guys are saving me bux!

[Hudechrome]

I took delivery of a Dell (gulp!) 2410 today, and after getting the calibrator up and running, I have to say it's much better than I ever expected.

No, it's not a Lacie or certainly not Eizo, but the essential characteristic for which I searched, beetter separation in the shadows, is there. Reminds me of the first time I used Plus -X. It was so linear.

For $400 expidited delivery, it's a bargain.

Av dE, 0.4, max dE, 1.47

Thanks again for all the feedback.

[Hudechrome]

Whoops! Make that the Dell 2412!

[D Fosse]

That's a good deal. Here in Norway it's $550 (and the U2410 by comparison $830).

Enjoy!

[D Fosse]

Hudechrome wrote:

it's not a Lacie or certainly not Eizo

One thing that was sort of missing in all the monitor discussions we had on the Windows forum is this: It is perfectly possible to do fine work on a less-than-perfect monitor, as long as you can identify the shortcomings and find ways to work around them. Although I'm happy with my particular Eizo, that's not to say it doesn't have its own shortcomings, so it's not an Eizo either .

[Hudechrome]

Quite true. I continued to do fine work with the old crt and it occurred often, the thought: "Why replace it now?" But then the foldover and edge contamination finally got to be too much. You can play Beethoven on an upright but oh that Steinway 9'!

Of course, my kids chiming in at Christmas with gift certificates to Amazon had nothing to do with it!

For the record, what are the cons to your Eizo (and which one?)

Message was edited by: Hudechrome

[D Fosse]

Hudechrome wrote:

what are the cons to your Eizo (and which one?)

Well, the S2243 is a PVA monitor, and PVA panels will always have some trouble in the deep shadows. But I knew that before I bought it, so it was no surprise. I've learned to interpret - and trust - the histogram to get my black levels right. It's not a problem.

The EV2335 that I use at home is IPS and probably comparable to your U2412. Since the price is less than half that of the S2243, I'm sure it has to be inferior in a whole number of ways, but I'll be damned if I can see how...except that it's standard gamut of course.

But pricing is a mystery to me. In general monitors become cheaper and cheaper, and generally Eizo has dropped dramatically in the last year or so. But some models go up and down without any apparent pattern, even directly from Eizo Norway. And one webshop sold the same model in black and gray for an extended period - at 30% price difference! And the funny thing is that the more expensive one went out first...food for thought...

Edit: there is one other thing: the EV2335 cannot be hardware calibrated to monitor LUT, it has to go via the video card. Not even the Eizo easy-pix (still hate that name) calibrator will do it.

[Paulo Skylar]

Along the same line of thought, it is possible to get adequate display performance when "full" color range is achieved with 6bits + FRC  (frame rate control). It depends on how well the FRC is done. I have no experience with the 2412, which does use 6it + FRC, but just because it is not 8-bit does not mean it is inadequate for good work. I believe the 2410 has 8-bit drivers and it might be interesting to see if users can tell the difference.

Paulo

[Hudechrome]

Here you go:

http://www.tftcentral.co.uk/reviews/dell_u2412m.htm

That was the big hurdle I saw because of the lack of any serious investigation until this review. When the 2412 was on the radar screen, I dropped it because of the 6+ bit but here is one review anyway that seems to indicate it not  be a problem.

I haven't run any other tests myself for things like banding but will do so soon.

In any case, I have 2 machines that both used crt's so this monitor would be the replacement for the LaCie crt.

Side note: The 21" Mitsubishi was almost more than I could handle getting it off my desk! Weight and clumsiness aided and abetted each other to cause consternation in the removal, not to mention a back that goes at the most inopportune times! I finally had to put it on a swivel chair to wheel it out of the room. But would you believe I just got an e-mail asking if he could have it? (I think he just bought a boat and forgot the anchor!)

[Hudechrome]

By the way, now that I am on a montor with restricted aRGB capability, would it be better to reset Photoshop color space to sRGB or leave it where it is: ProPhoto? I left it alone at the moment because it would seem to me that allowing the files to live in the larger color space to be adviseable in the long term.

[D Fosse]

Leave it in ProPhoto. You never know what the future brings