Photo Contests, JPEG, and DPI

This post is about something that bothers me a lot. Especially, because it originates from a place where you think they should know better. It's about Dots-Per-Inch (DPI) and JPEG (the popular digital image/photo format).

It all starts, when I read the requirements of certain online photo contests. The criteria for entering the contest contain the following: The photo entering the contest must be in JPEG with maximum quality (least compression), AND 300 DPI.

Posted on August 26, 2016 and filed under Annoying, Photography, Personal, Tips'n Tricks.

Disable Fritzbox Provider Services

This weekend went my Internet (VDLS) down. The DSL part was still up, but the IPv4 connectivity (over PPPoE) was down. When I checked the Fritzbox (7340) I saw that the DLS had 'trained' on ~100Mbps down and ~30Mbps up. Connection speeds I could only dream of......

Trying to re-establish the IPv4 connection I restarted the DSL modem. Upon reboot, it trained on about 70Mbps download and 30Mbps upload, and the PPPoE tunnel for IPv4 established nicely..... for about 5 minutes.

It turned out that the DSL connection tried to get a better connection, and got it. So starting off at 70Mbps, it could establish a 74Mbps a couple of seconds later, and 75Mbps a bit later after that, and so on, and so on. During this time the PPPoE connection worked like a charm. Until the DSL reached the magical 100Mbps rate. That's when the PPPoE (and the actual IPv4 connection to the Internet) failed.

Posted on May 17, 2016 and filed under Annoying, Hardware, Internet, Tips'n Tricks.

The Moon and Jupiter

Last night I was able to capture both the Moon and Jupiter in one frame. Jupiter is (barely) visible on the left side of the photo.

Moon and Jupiter next to each other in the night sky

The following screen capture of the iOS app 'Star Walk' from my iPhone is added for reference.

Star Walk - Moon and Jupiter reference

Posted on April 18, 2016 and filed under Photography.

Why Encryption Matters

John Oliver addresses the need for encryption in an hilarious way. The clip is ~18 minutes, but well worth it.

If you still think that encryption is only used for evil (terrorism, child pornography, etc.), and that governments / security agencies should need (backdoor) access to your data..... Well, I'm not gonna end that sentence.

Posted on April 12, 2016 and filed under Fun, Internet, Privacy, Security, Video.

Run Juniper Virtual SRX in VMWare Workstation

The Juniper Virtual SRX firewall can run on multiple platforms, but VMware Workstation is not mentioned in the list of supported platforms. Having some experience with both, I know that almost all VM's designed for the VMware ESXi environment will run on the (stand-alone) VMware Workstation product.

I downloaded the .ova file from the Juniper website and imported it in VMware Workstation v12.1. During the import I adjusted the number of CPU's to save resources, which turned out to be a mistake. The VM really needs the two CPU's, because if you don't it just won't work (routing failures, etc..). So, don't change the defaults for CPU and memory.

Posted on January 12, 2016 and filed under Junos, Security, Tips'n Tricks.

Kodi Media Playback Stops Frequently

Ever since the good-old Popcorn Hour died last year, we've been consuming our media through a Minix media player with XBMC, or Kodi as it's called since version 15. And even though this was a complete package (everything configured and pre-installed), it had a learning curve and required more maintenance than the Popcorn Hour.

A couple of weeks back, we started to experience cut-offs in the media we were consuming. TV shows, and movies stopped for no reason. The image froze, audio cut-out, and the subtitles would go on like nothing was wrong. After a few seconds display goes black, and after 5 to 10 seconds the Kodi-menu would present itself.
At this point we would select play, and the TV show, or movie would continue were it had stopped.

The stopping (or crashing) of the media could occur 1-10 times in a movie and a couple of times in a TV show. One or two times is already annoying, so you can imaging what 10 or 15 'crashes' might invoke....

Posted on December 1, 2015 and filed under Tips'n Tricks, Software, Hardware, Annoying.

Firefox v42 Tracking Protection

With the launch of Firefox v42 (and up) they introduced an adBlocker in the browser. The ad blocking feature is available (by default) during the use of Private Browsing.

But if you don't want to see those advertisements, and for some reason you don't want to use Private Browsing (like me), than you're out of luck (by default). There's no normal way to enable this feature without the use of Private Browsing (or use an adBlocker add-on for Firefox). Thankfully, Firefox uses a config module in which you can tweak almost everything.... including the Tracking Protection.

Posted on November 4, 2015 and filed under Browsers, Internet, Privacy, Security, Software, Tips'n Tricks.

Fuji X-T1 Electronic Versus Mechanical Shutter

A couple of months ago, Fuji released a highly anticipated firmware version featuring several new functions for the Fujifilm X-T1 digital camera. One of those being an electronic shutter mode.

The original mechanical shutter gives you a or minimum shutter speed of 1/4000second. This is not that fast, compared to the average dSLR, where 1/8000 second seems to be the standard. Another 'problem' is that you can't use fast lenses (f/1.2, f1/4) in (bright) daylight, without the use of ND-filters.

Posted on August 30, 2015 and filed under Photography, Tips'n Tricks.

Apple iOS Personal Hotspot Annoyances

This week, I ran into an annoying feature regarding the Apple iOS Personal Hotspot function of my iPhone 5s. I had to do some software testing with various WiFi clients. This worked fine, up to the moment that new devices ran into connectivity problems.

The new devices could connect, but got a message that there was no/limited Internet connectivity. Checking the IP address of the devices showed that they had an 169 address assigned.
So the iPhone wouldn't give new IP addresses to the new devices. Earlier devices that connected correctly could reconnect without a problem though.

It turned out to be a 'normal' DHCP problem. The IP address scope on the iPhone was depleted.

The iPhone has a small DHCP address pool that can give out 16 addresses ( Of these 16 addresses are 3 taken by the network, broadcast ( and and iPhone itself ( Leaving 13 addresses for other devices.

In normal situations, this shouldn't be a problem, but when your testing stuff, you can run into a shortage of IP addresses. Besides the shortage of addresses there is another challenge; no way of altering the DHCP lease time, or even clearing the issued IP addresses.

The lease time for the DHCP address is approximately 1 day (85536 seconds), as shown by a little network traffic capturing below.

20:53:29.544291 56:e4:3a:38:4d:64 > 00:23:6c:8d:7f:8e, ethertype IPv4 (0x0800), length 342: (tos 0x0, ttl 255, id 45806, offset 0, flags [none], proto UDP (17), length 328) > BOOTP/DHCP, Reply, length 300, xid 0xfd7e0982, Flags [none]
      Client-Ethernet-Address 00:23:6c:8d:7f:8e
      sname "Free-Public-WiFi"
      Vendor-rfc1048 Extensions
        Magic Cookie 0x63825363
        DHCP-Message Option 53, length 1: ACK
        Server-ID Option 54, length 4:
        Lease-Time Option 51, length 4: 85536
        Subnet-Mask Option 1, length 4:
        Default-Gateway Option 3, length 4:
        Domain-Name-Server Option 6, length 4:

There is a function to reset the network settings on the iPhone, but that just clears everything regarding (wireless) network settings, but it doesn't touch the DHCP service in the iPhone. A reboot of the iPhone doesn't do the trick either. So you just have to wait till it clears automagically.

So there is room for improvement......

Posted on July 30, 2015 and filed under Annoying, Apple, iPhone, Tips'n Tricks.