Monitor colour control

[DaveO]

We ponder and agonize over "neutral" tones but do we know if the colours we see on the monitor in front of our eyes are anywhere near "correct"?

 

Here's a useful link about monitor calibration, scroll down to the bottom to see how the grey scale and coloured scales look to you. You might just be surprised.

 

http://www.imagescie...rol+on+Monitors

 

Dave

[colinbm]

Dave, Don't you like Shirley ?

Col

[enricosavazzi]

Several years ago I used to calibrate my CRT monitor with one of the USB devices that, basically, take a one-pixel image of part of a monitor and send it to software that then creates a profile for the monitor. The recommendation of the maker of the calibration hardware+software package was at the time to repeat the procedure at least once a month, or perhaps once a week, I don't remember. I did this a few times, but the changes were extremely small. I got bored afterwards.

 

I did the same a few times with my first LCD monitors (equipped with electroluminescent backlighting) out of curiosity, and after the first calibration I always obtained the same readings. I did not try to recalibrate my LCD monitors with LED backlighting, but I should expect they are even more stable. On the other hand, I looked at the spectra of the electroluminescent backlighting, and it has literally dozens of peaks and valleys. The spectrum of my LED backlighting is instead the same as a typical "white" LED (one sharp peak in the blue and a rounded one in the green-to red region, with a deep valley between the two peaks).

 

Regardless of what the makers of monitor calibration devices say, I think what we really need is one initial calibration, and perhaps repeat it every few years afterwards. However, there are limitations to what a monitor profile can do. Since all these monitors only have three color channels that can be balanced (each containing in practice one or multiple peaks that cannot be balanced), there will always be some peculiar subjects that emit narrow-band spectra that will look different to our eyes on direct visual observation and after a lens-camera-debayering-storage-display chain.

 

I don't know how consistent is the color-rendering quality of a modern LCD monitor factory. We all know that, in a TV shop, it is easy to see that many TVs display their own personal interpretation of color, different from other neighboring TVs. However, TVs have plenty of user settings that can be played with by the shop personnel and customers. Computer monitors typically don't, except for color saturation, contrast/luminosity and, in some models individual levels of the three color channels. In fact, LCD computer monitors on shop shelves seem to display a more consistent color rendering than TVs.

 

It would be good to be able to rent a monitor calibrator and use it to create the initial monitor profile. A good monitor calibrator is probably too expensive for the large majority of us to justify buying. Of course this is not what the makers of monitor calibration devices want us to do.

[nfoto]

I'm using Eye-One probe (by GretagMacBeth, now known as X-Rite) everywhere (stationary machines as well as lap ops). The old CRT monitors changed colours quite substantially over their life span so at least monthly recalibrating was required. Today's flatscreens are much more stable and checking them a few times per year suffices. Do beware they also will alter their response towards the end of their life span, so if your monitor suddenly cannot achieve the brightness off its earlier days, colours are likely altered as well.

 

Most lap top displays are not aimed at being used for image evaluation and often have a restricted gamut. Any calibrating on these is likely to yield poor results and image processing with such devices can be a hit-or-miss affair. The W-series Thinkpads from Lenovo do have very decent display though and they are claimed to be 95% of Adobe RGB in gamut.

 

A final point worth noting is that most monitors are set to run at far too high brightness and this causes issues if you are into pre-press production preparing files for printing to books or magazines.

[nfoto]

By the way, the test chart Dave linked to came across perfectly on my current working machine (a W520). So what I see is probably what the image is supposed to look like.

 

Set up in a stationary configuration, the W520 drives two additional monitors and the colour shift occurring on these additional monitors can be alarming (they only serve to increase screen estate to 5120x1200 pix for programming, TV watching, and other non-critical tasks so nothing to worry about). If I really wonder how an image is supposed to appear, I just move it to the main monitor.

[Andrea B.]

I really like that Aus website. Have gone there in the past to learn from.

 

The colour and tone patches showed up well on my Macbook Pro Retina except for the two darkest patches in each row which were not easy to separate.

[nfoto]

Perhaps you have gone in the opposite direction from the usual and run your monitor at too low brightness?