Comparing lenses

I got my ReasyCase yesterday! The case feels fine. It is sturdy, reasonably slim, and carries a small serrated metal pice which also works as a bottle opener. Also on the back is a slim USB memory (16GB) which doubles as a stand for the case – handy!

With it came two lenses. Since I already had a couple of Gizmon lenses, I made a comparison between the two pairs.




The top image compares the lenses marked as “fisheye”. As you can see, the Gizmon on the right is the best.

The middle image compares the wide lenses. Not much difference, but again, the Gizmon is wider.

The bottom picture is taken without a lens.

The wide lenses can be “opened” and used as macro lenses. Here the ReadyCase lens has a better magnification than the Gizmon.


Thoughts from my first Mentimeter experience

Today I tried Mentimeter for the first time in the classroom. Previously, I have been using the ActiVote system from Promethean, but as I only have access to 32 units and my student group has 51 students, I had to find an alternative solution.

Last year I tried to use Socrative instead of the ActiVote, and got quite bad feedback from the students. The ActiVote, as a physical device has an ease of use for the user that I believe is very hard to transfer to a screen based system. With a physical device, there is no need to log in or start anything, you just pick up the device and press a button.

Anyway, I prepared a set of questions to use at the end of my lecture. Mentimeter’s question presentation is much better than Socrative’s and ActiVote’s. Also, it is good that the students are able to see the question and answer on the device if they find it hard to read the question projected in the front of the lecture hall.

My use of the student response system today was to implement peer instruction. I do not use it as a grading mechanism, so not having to create an account or provide a user name when using Mentimeter works out great for me. This is also possible in Socrative and GoSoapBox which is another system I have been looking into.

Of these services, Mentimeter is the only one to provide a projector view. What both Socrative and GoSoapBox use which Mentimeter does not provide is a virtual “room” or “event” that students can join. GoSoapBox e.g. lets me create an event and a custom event ID which the students enter to join. Once in the room or event, I can open questions that are “pushed” to the students interface. They do not need to enter a code each time.

However, as I only had one session at the end of the lecture, the lack of a room in Mentimeter was not an issue. The process was also streamlined enough that I do not think it will be a large obstacle when I have multiple quiz sessions in future lectures.

Overall, I will continue to use Mentimeter for my lectures. I think I will have to try GoSoapBox also though.

Installed CrashPlan on my ReadyNAS Ultra 4

I use CrashPlan+ (20% discount link, I do not get any bonus) to backup my computer (Mac) to the cloud in addition to using TimeMachine. I just installed CrashPlan on my ReadyNAS Ultra 4 for automatic backup 🙂 Here is how I did it (adapted from these instructions. You will have to buy an extra subscription for the NAS or upgrade your existing subscription to a Family subscription. Installing CrashPlan on the ReadyNAS itself rather than adding the NAS when mounted to your computer means that the NAS can backup itself. In my case this also means a faster backup since I use WiFi on my computer and the NAS is directly connected to my router.

Go to the CrashPlan-install directory and run ./

% cd CrashPlan-install
% ./

Below follows a dump of my interactions:

Do you accept and agree to be bound by the EULA? (yes/no) yes

What directory do you wish to install CrashPlan to? [/usr/local/crashplan]
/usr/local/crashplan does not exist.  Create /usr/local/crashplan? (y/n) [y]

What directory do you wish to link the CrashPlan executable to? [/usr/local/bin]

What directory do you wish to store backups in? [/usr/local/var/crashplan] /crashplan-backup
/crashplan-backup does not exist.  Create /crashplan-backup? (y/n) [y]

What directory contains your SYSV init scripts? [/etc/init.d]

What directory contains your runlevel init links? [/etc/rc2.d]

Your selections:
CrashPlan will install to: /usr/local/crashplan
And put links to binaries in: /usr/local/bin
And store datas in: /crashplan-backup
Your init.d dir is: /etc/init.d
Your current runlevel directory is: /etc/rc2.d

Is this correct? (y/n) [y]
  • Configure the client on the ReadyNAS via GUI on desktop by following the instructions for configuring a headless client. Below is a summarization of the steps.
    • Quit the CrashPlan Desktop client on the machine you want to use to configure the client on the ReadyNAS (machine will be referred to as
    • Edit the file (on a Mac: /Applications/ to use service port 4200 (uncomment and edit the line servicePort parameter)
    • Create a SSH port forward to your ReadyNAS (from a Mac, open a terminal and type ssh -N -L 4200:localhost:4243 root@<ReadyNAS IP-address>)
    • Start the CrashPlan Desktop client on
    • Configure backup of ReadyNAS (login to account, set up subscription, select folders to backup).

Update: Here is a post on how to update the CrashPlan client/Java version.