W520 colour sensor

[magekyou]

Can anyone tell me about the colour sensor ? What is its purpose ? Given its low price is it advisable to buy it ?
Thank you.

[MikeM]

Can anyone tell me about the colour sensor ? What is its purpose ? Given its low price is it advisable to buy it ?
Thank you.

I just today returned my W520 with the color sensor / calibrator back to Lenovo for a refund so I will not be able to answer much since I do not have possession of it any longer, but while I had it I used it twice. This is how it went:

The display looked fine to me when I started up the laptop fresh from the factory. I used the color calibrator, which has a sensor next to the fingerprint scanner, by starting the software and closing the lid so the sensor can scan the screen. You are supposed to leave the lid closed while the scanner runs and while the scanner runs the screen changes colors. I know because I cheated and peeked while it was running. I had to start the scan over after it sensed that someone had popped the lid, so I let it cycle out, which took not a very long time - I'd guess a minute or so. While it scans it beeps intermittently and a green indicator LED tied to the calibrator illuminates on the back of the computer lid. After it ran it asks how you like it and you can save it. This is all from memory, so bear with me if I miss dotting an I on this. You can select before you calibrate one of like 3 different schemes.

After I ran the calibration the photo that I was using as the desktop background, the Windows 7 pic of the large brown rock with a blue colored beach had the rock looking like the dawning sun was going to scorch the side of it off. It looked pretty good, but I can't say it was better than how the monitor was calibrated at the factory. The W520 screen that I had was very nice. It did look hotter after I calibrated it though.

I worked in the commercial printing business for over 30 years but I don't have a Pantone book here anymore so I did not check it for color correctness or anything. I'm not a pro photographer, so I couldn't say how accurate it was for that purpose, but what was neat was that I could easily adjust it for different purposes with results that were perfectly satisfactory for my humble uses. I bought it only because it was so inexpensive and I have a personal penchant for sometimes playing with computer hardware that I don't need.

Hope this helps you out.

[davidhbrown]

The color sensor / calibrator profiles the built-in monitor *only*, allowing the computer to adjust it to better match the color temperature and gamma you specify. Given the limitations of the 95%-NTSC gamut and 6-bit-per-pixel FHD screen (and the others are worse), this needs to be considered a "best effort" not a proof-quality setup.

Still, I spent a *lot* of time trying to adjust the individual gamma curves on my dearly departed T61p's screen to get anywhere close to my main monitor. Having the color calibrator in the W520 lets me just not worry about it -- I presume the software/hardware is doing better than I could without investing in additional hardware.

If you already have a standalone monitor calibrator, purchasing one that works only with one screen wouldn't make much sense. I haven't done more than very occasional prepress work for about 8 years, so while it still bothers me when a screen is very wrong, I haven't bought such hardware.

[magekyou]

Thank you guys! Your help is greatly appreciated! So if I understand correctly, it does not hurt to get it. Is it easy to revert to factory settings after use

[davidhbrown]

A one-time hurt to your wallet, I suppose. And perhaps a bit of hurt if you show it to someone and they say incredulously, "that's calibrated??!?"

A quick answer to "is it easy to revert to factory settings" is yes... you'd go to the Color Management control panel and delete the custom profiles.

The way the calibrator works with the OS is to create a ".icm" profile which can be viewed through the Color Management control panel. (The filename is [tt]ThinkPad Display 1920x1080_D##_ddmmyy_hhiiss.icm[/rr] where ## is the white point (D50, D65, D75) you selected and ddmmyy_hhiiss is when you created the profile. (I suppose if you don't have the FHD screen, the 1920x1080 could be different, too.) The gamma you requested isn't part of the filename.

Now, I've turned off part of the software so it doesn't nag me about calibrating the external monitor. So, my problems with the calibration not always coming up at restart may be my fault. However, with calibration being baked into the OS, what you want to do is go to the "Advanced" tab and make sure the "Use Windows display calibration" is turned on in the System Defaults screen. (You will to be an administrator.) Then the display reflects whatever you have selected as the default ICC profile for the device. [Edit: that wasn't the most understandable thing I ever wrote. But there is online help for the CP, too!]

And, so, to turn it off *without* deleting your profiles, you can just select "Lenovo ThinkPad LCD Monitor" and make that the default profile for the ThinkPad Display 1920x1080 device.

It is nice to be able to jump among these saved white points. That sure beats tweaking gamma by hand in the NVIDIA control panel!

[Volker]

After I ran the calibration the photo that I was using as the desktop background, the Windows 7 pic of the large brown rock with a blue colored beach had the rock looking like the dawning sun was going to scorch the side of it off.

Sounds about right, standard desktop backgrounds have distorted colors to look good on crappy panels with bad color reproduction. Calibration isn't about making pictures look better on screen, it is about showing the same colors as in the print.