You are currently browsing the archives for the Computers category

Spyder4Pro vs X-Rite ColorMunki

Spyder4Pro and X-Rite ColorMunki are the two most popular consumer-level monitor calibrators available in the market. Like many people, I also asked myself the question “Which one is better and which one should I buy?”. They both are priced similarly and therefore the money is not an important factor for the decision.

Previously, I had borrowed Spyder3Elite from a friend to calibrate my laptop’s monitor (Dell XPS 15z) and my external monitor (HP ZR24w). Then I was quite happy with the result. Later, with the increased importance of the accurate color representation in my photos I had the necessity to buy one for myself and stop borrowing from friends.

Since I was already familiar with Spyder I decided to buy Spyder4Pro. However, the calibration results for my laptop display didn’t seem satisfactory to me, although the calibration for the external HP monitor was very good. The laptop had some green tint on grays and yellow to beige cast on whites. I tried many different types of calibration configurations but the green tint did not go. I even get in contact with the customer support at Datacolor but they happened to be quite unhelpful.

Then I start reading in forums about the issue. I found that many people complain against Spyder4Pro because of different reasons including a green tint but also there were quite satisfied users. At several places I read that X-Rite is the choice for professionals. Then decided to buy X-Rite ColorMunki, too. I bought X-Rite ColorMunki together with a Color Passport Checker for the same price as Spyder4Pro.

Unfortunately, X-Rite did not provide satisfactory results, either. The calibration with ColorMunki had also green tint on grays and yellow to beige tint on whites. I would say that the perceptual results were even more disappointing mainly because the calibration with X-Rite ColorMunki somehow had less contrast compared to the calibration with Spyder4Pro. It is well studied that the higher contrast makes the perceived image more aesthetic.

Like with the Spyder4Pro, the calibration of the HP monitor with X-Rite was also very good but again with slightly lower contrast. Having consistently bad calibration results for my laptop display and consistently good calibration results for the external monitor I concluded that my laptop’s monitor is not as good as the external HP monitor. In fact, Spyder4Pro reported that the laptop’s display covers 79% of the sRGB color space whereas the HP cover 98% of the sRGB color space. Probably, the calibrators fail to make a proper calibration for not so good monitors that have poor sRGB coverage. In few forums I have read reviews people complaining about green tint on grays and yellow to beige cast on whites. This further supports my hypothesis – you cannot make a monitor display a color if it simply has no capabilities to do so.

Differences between Spyder4Pro and X-Rite ColorMunki

So here I will outline the main differences between these two calibrators by giving examples and referring only to the calibration of my external HP ZR24w monitor. These two calibrators definitely operate in different way and generate different results.

The Luminance Reading

During the calibration process, both devices ask you to manually adjust your monitor’s brightness and contrast until the calibrator reads 120cd/m2. I find this the most important difference and a proof of how different these devices are. Spyder4Pro reads 120cd/m2 when the monitor’s brightness is set to 70 and the contrast to 75. However, with the same monitor settings X-Rite ColorMunki reads 163cd/m2. On the other side, X-Rite ColorMunki reads 120cd/m2 when the monitor’s brightness is set to 60 and the contrast to 64. But then, Spyder4Pro reads 91.3cd/m2. The mismatch in this reading shows that Spyder4Pro is less sensitive to light or simply one of the devices malfunctions. I would ignore the latter option.

High vs Low Contrast

Spyder4Pro generates a profile where grays appear darker or as if there is more contrast. As shown in the photo of the monitor below, somehow the gradient is not liner. The darks become suddenly too dark. On the other side the gradient on a calibration with X-Rite ColorMunki looks smoother. In fact in a properly calibrated monitor (with proper gamma value), the luminance (perceived intensity) of the grays should be linear (smoother). Because of this I would say that X-Rite ColorMunki achieved better gamma setting than Spyder4Pro. Nevertheless, these two calibrators seem to be good enough for most people out there.

1920x1080 same luminance reading without text‚Äč

You can also watch the short clip which I took while doing this experiment.

Vodafone ADSL Turbo 35Mb/s in Spain – Speed Test

For some time I have changed my ADSL internet provider to Vodafone.

I have contracted the marketed ADSL Turbo – which promises download speed up to 35Mb/s and upload speed up to 3.5MMb/s.

Here is my actual speed results which I got from

Download speed: 30.3Mb/s

Upload speed: 4.65Mb/s


Vodafone ADSL Turbo Speed Test


Well the download is not 35Mb/s but it is still good. I mostly care for the upload becaus which seems to be good. Typical ADSL providers offer upload speed up to 1Mb/s which is quite a junk – especially these days when we share quite a lot of home media files. Overall I would say I am quite satisfied for the price quality – probably it is the best on the market as of today.

Upload speed on Ethernet very low

Today I had installed fiber optic internet – 100Mbps download and 10Mbps upload. I was eager to test the speed. I immediately run to which measured download at the rang of 93Mbps but the disappointing 1Mbps upload. Then I urged to check the speed on my wife's laptop. Her upload was about 11Mbps. Then I tested the speed with on my laptop (Dell XPS 15z) over the WiFi. On the WiFi the download was 20Mbps and the upload around 11Mbps. This was a really strange situation. Then I searched on google and found this article on Dell's forum describing the exact problem which I had – The problem was that I had installed a program Expact Shield which I used to watch BBC iPlayer. Expact Shield installs a VPN which somehow tunnels and slows the upload speed (probably they get a copy of what I send). After you uninstall it the problem upload problem over the Ethernet disappeared.

Disable the auto popup toolbar during full screen mode in VMWare Workstation 8

I frequently develop in a guest OS which I run on VMWare Workstation. I usually run the guest OS in full screen mode in one of my monitors. However, when I move the mouse to the top corner the monitor VMWare's toolbar pops up. Sometimes this can be very annoying because the application menu under it is not accessible and you have to wait until the toolbar hides again. I always wanted to disable the toolbar at all. However, I could not find any way to disable and remove it – as I understand there is not such functionality in VMWare Workstation 8.

Luckily I found a workaround for it. I used special configuration parameters to delay the popup of the toolbar with arbitrary time. What you need to do is add the following lines (colored in green) in VMware's preferences.ini file.


pref.fullscreen.showDelay = "5000" — delay the showing of the toolbar 5000ms (5 seconds) 

pref.fullscreen.hideDelay = "1000" — hide the toolbar after 1000ms (1 second)

In Win7 the preferences.ini file is located at




How to – Dell XPS 15z – Battery Replacement

I have just seen on Dell's support site a how to for replacing a battery of Dell XPS 15z. The battery of this computer is embedded and the replacement requires opening the box. But the procedure is really straightforward. I have also searched a non-Dell place where one could buy a cheap replacement battery but unfortunately did not find any. The only I know is Dell and price tag is about $185 – which is pretty expensive.

By the way, there is one procedure which I follow to extend the battery life of my computer. When it is plugged, I disable battery charging from the power options – (down right next to the clock or Fn+F3). Based on my prior experience this approach extends the battery life to years unless the battery has some fabrication defect. 

Backspace in Vim does not work

Soon I had a problem of the backspace key in vim. I am connecting to a remote machine through VNC. When I open Vim in Xterminal (xterm) and press the backspace key it prints ^? Instead of doing deleting the character before the cursor. I did waste few hours to find a fix and here it is:

In Vim when you press the backspace key it prints ^?
Solution 1
Try adding the following line in file .vimrc
set backspace=2
It did not work?
Solution 2
Add the following lines in your .vimrc file.
if &term=="xterm"
  set t_kb=<CTRL+V><BS>

<CTRL+V> means to press the control key and “V”. Not to type the string as is
<BS> means to press the backspace key
This combination of keystrokes will generate the code mapped to backspace key.
And all the lines above essentially will make proper correct mapping for the backspace key.

It did not work? Then, I don’t know how you can fix it.

Dell XPS 15z

I have just ordered the new and very elegant Dell XPS 15z and don't have patience to have it in my hands. This laptop seems to be quite powerful.

CPU: Intel Core i7-2620M 2.7 GHz
HDD: 750GB 7200rpm
Screen: 15.6” 1920×1080 resolution HD
Video card: 2GB NVIDIA GeForce GT 525M
Battery: 8 cells
Weight: 2.5 kg (5.5 lb)
Price: 1399 Euros

All these power is in a stylish box less then 1” (2.5cm) thick and weights 2.5kg.

It’s competitor which comes behind it is Mac Book Pro 15. Although its less powerful characteristics, Mac Book Pro 15 is way overpriced and costs 2229 Euros (830 Euros more). But never mind, Apple worshipers like to be ripped off :)

The unpacking and hands on post comes soon.

Hamachi Bug Is Causing DNS Problems

I have installed hamachi on my windows 7. When I change my network adapter, after a while my computer cannot resolve DNS addresses. For example, at home I use WiFi. I suspend my computer and go to the office. At work I connect to the wired Ethernet connection (i.e. change the network adapter) and after a while my system is unable to resolve DNS addresses.

Solution for this is either to reboot the computer or disable the hamachi adapter from Network Connections (Control Panel\Network and Internet\Network Connections).

C# application for IBM/Lenovo Thinkpad Temperature and Fan Sensors

I have soon implemented a C# application that reads and displays the temperature and fans sensors in IBM/Lenovo Thinkpad laptops. You can download it from It is free and open source (GPL v3.0).

Compatible with:

  • ThinkPad A31
  • ThinkPad R51
  • ThinkPad T40
  • ThinkPad T43, T43p
  • ThinkPad T60
  • ThinkPad T61
  • ThinkPad T61p
  • ThinkPad X31
  • ThinkPad T400
  • ThinkPad T400s
  • ThinkPad T500


WebCam A4Tech Drivers (PK-35N, PK-635, PK-935)

I am uploading my old webcam's drivers so that I can find them easily when I need them and also those who lost their drivers:)

WebCam A4Tech Drivers (PK-35N, PK-635, PK-935)